Journal

2025

1. J. Park†, B. J. Kang†, G. Seo, J. Kim, T. G. Park, S. Nam, J. J. Yoo, K. Lee, Y. U. Jeong, M. Park, S. S. Shin*, F. Rotermund*, "Cross-correlation between crystallinity and optoelectronic properties of mixed perovskite thin films through multiple time-resolved spectroscopy," Adv. Energy Mater. 15, 2400225 (2025).

2. J. Lee†, C. Sun†, J. Park†, C. Kim, S. Lee, D. Lee, M.-H. Lee, B. Kim, Y. H. Kim, J. Kim, S. Lee, S. Jeong, W. B. Ying, X. Song, S. Cho, F. Rotermund*, Y.-H. Kim*, J.-Y. Lee*, "High Efficiency (>10%) AgBiS2 Colloidal Nanocrystal Solar Cells with Diketopyrrolopyrrole-Based Polymer Hole Transport Layer," Adv. Mater. (2025) in press.

2024    

1. I. C. Yu†, J. H. Oh†, J.-H. Shim, K.-J. Kim, B.-G. Park, D.-H. Kim, K.-W. Kim, H.-W. Lee, K.-J. Lee*, F. Rotermund*, "Laser-induced coherent spin change due to spin-orbit coupling," npj Spintronics (2024) in press.

2. D. W. Kim†, S. Won†, J.-H. Park, Y.-J. Kim*, F. Rotermund*, "Sub-picosecond mode-locked laser operation in a femtosecond-lased-inscribed Yb:CaF2 channel waveguide," Opt. Express 32, 42801 (2024).

3. T. G. Park, S. Baek, J. Park, E.-C. Shin, H. R. Na, E.-T. Oh, S.-H. Chun, Y.-H. Kim*, S. Lee*, F. Rotermund*, "Spectroscopic Evidence of Ultrafast Topological Phase Transition by Light-Driven Strain," ACS Nano 18, 30966 (2024).

4. C.-W. Lee†, C. Kim†, W. Yoon, H. Yun, M. Jazbinsek, F. Rotermund*, O-P. Kwon*, “Organic THz crystals based on off-diagonal optical nonlinearity with optimal in-plane polar axis,” Adv. Opt. Mater. 12, 2401590 (2024).

5. H. S. Bark, M.-W. Park, J. E. Bae, K.-H. Jang, Y. U. Jeong, K. Lee, F. Rotermund*, T.-I. Jeon*, "Enhanced terahertz characterization of multilayer graphene on guided-mode resonance filter: Boosting sensitivity and precision in electrical and optical characteristics," Adv. Mater. Technol. (2024) in press.    

6. D. W. Kim, K. H. Ko, F. Rotermund, "Soliton mode-locking and numerical analysis of Yb3+-doped potassium double tungstate lasers in compact laser cavitiy geometries," Kor. J. Opt. Photon. 35, 241 (2024) (in Korean).

7. S. C. Lee†, S. Park†, D. Suk, J. Hwang, K. Ko, W. B. Cho, D.-Y. Choi, K.-H. Ko, F. Rotermund*, H. Lee*, "On-chip mid-infrared dispersive wave generation at targeted molecular absorption wavelengths," APL Photon. 9, 080802 (2024).  

8. J.-A Yang†, C.-W. Lee†, C. Kim†, M. Auer†, I. C. Yu, J. Oh, W. Yoon, H. Yun, D. Kim, M. Jazbinsek*, F. Rotermund*, O-P. Kwon*, “Chiral cationic chromophores: A new class of efficient ultrabroadband THz crystals,” Adv. Opt. Mater. 12, 2400343 (2024).

9. G.-E. Yoon†, D.-J. Kim†, Y.-J. Park†, C. Kim†, S.-J. Kim, B.-R. Shin, Y.-S. Lee, C.-W. Lee, J.-W. Park, I. C. Yu, W. Yoon, H. Yun, D. Kim, M. Jazbinsek*, F. Rotermund*, O-P. Kwon*, “Symmetry reduction of molecular shape of cationic chromophores for high-performance terahertz generators,” Adv. Opt. Mater. 12, 2400413 (2024).

10. J. E. Bae, M. Hyun, D. W. Kim, X. Mateos, J. G. Ajates, C. Ro,ero, J. R. V. D. Aldana, J. Kim*, F. Rotermund*, "Characterization of noise spectra in low-jitter GHz mode-locked fs-laser-inscribed waveguide lasers," Opt. Laser Tech. 179, 111412 (2024).

11. C. Lee†, E.-T. Oh†, T. G. Park, S. Lee, S. J. Kim, Y.-S. Choi*, F. Rotermund*, D. K. Yoon*, "Terahertz-polarizing Effect Based on Geometric Anisotropy of Ti3C2Tx MXene Nanosheets," Carbon 225, 119156 (2024).

12. I. C. Yu, B.-G. Park, S. B. Kim, N. Noh, J. M. Yuk, Y. Kim, F. Rotermund, "Study on microscopic origin of spin excitation in TmFeO3 by time-resolved muticolor optical pump-probe spectroscopy," Curr. Appl. Phys. 62, 54 (2024).

13. V. Juvekar, D. J. Lee, T. G. Park, R. Samanta, P. Kasar, C. Kim, F. Rotermund*, H. M. Kim*, "Two-photon excitation photosensitizers for photodynamic therapy: From small-molecules to nano-complex systems," Coord. Chem. Rev. 506, 215711 (2024).

14. T. G. Park, C. Kim, E.-T. Oh, H. R. Na, S.-H. Chun, Y.-H. Kim, S. Lee, F. Rotermund, "Ultrafast acousto-optic modulation at the near-infrared spectral range by interlayer vibrations," Nanophoton. 13, 1059 (2024).

2023   

1. W. B. Cho, J. E. Bae, S. C. Lee, N. S. Myoung, F. Rotermund, "Femtosecond Mid-IR Cr:ZnS laser with trasmitting graphene-ZnSe saturable absorber," Curr. Opt. Photon. 7, 738 (2023). 

2. B.-R. Shin, U. Puc, Y.J. Park, D.-J. Kim, C.-W. Lee, W. Yoon, H. Yun, C. Kim, F. Rotermund, M. Jazbinsek, O-P. Kwon, “Design of high-performance organic nonlinear optical and terahertz crystals by controlling the van der Waals volume,” Adv. Sci. 10, 2304767 (2023).

3. D.-J. Kim†, I. C. Yu†, M. Jazbinsek, C. Kim, W. Yoon, H. Yun, D.-W. Kim, F. Rotermund*, O-P. Kwon*, “Local rigidity by flexibility: Unusual design for organic THz-device materials,” Adv. Opt. Mater. 11, 2300807 (2023).

4. T. G. Park, S. Baek, J. Park, E.-C. Shin, H. R. Na, E.-T. Oh, S.-H. Chun, Y.-H. Kim, S. Lee, F. Rotermund, "Ultrafast switching of topological invariants by light-driven strain," arXiv:2306.09766 (2023).

5. J. Hwang, S. Park, K. Ko, D. Suk, Y.-H. Lee, D.-Y. Choi, F. Rotermund, K.-H. Ko, H. Lee, "Quantitative gas pressure measurement by molecular spectroscopy using chip-based supercontinuum in the mid-infrared," Opt. Express 31, 35624 (2023). 

6. B.-R. Shin†, I. C. Yu†, U. Puc†, W. T. Kim, W. Yoon, C. Kim, H. Yun, D. Kim, M. Jazbinsek*, F. Rotermund*, O-P. Kwon*, “Design and Validation of Isomorphic Crystal Library for Nonlinear Optics and THz Wave Generation,” Adv. Opt. Mater. 11, 2201420 (2023).

7. S.-J. Kim†, I. C. Yu†, D.-J. Kim, M. Jazbinsek, W. Yoon, H. Yun, D. Kim, F. Rotermund*, O-P. Kwon*, “A New Class of Organic Crystals with Extremely Large Hyperpolarizability: Efficient THz wave generation with wide flatpspectral-band,” Adv. Funct. Mater. 33, 2209915 (2023).

8. B.-R. Shin†, I. C. Yu†, M. Jazbinsek, W. Yoon, H. Yun, S.-W. Kim, D. Kim, F. Rotermund*, O-P. Kwon*, “Dichlorinated organic-salt terahertz sources for THz spectroscopy,” Adv. Opt. Mater. 11, 2202027 (2023). 

9. B.-R. Shin†, I. C. Yu†, M.-H. Shin, M. Jazbinsek, F. Rotermund*, O-P. Kwon*, “Efficient Organic Terahertz Generator with Extremely Broad THz Absorption-Free Range,” APL Mater. 11, 011101 (2023).

2022 

1. J.-H. Park†, W. T. Kim†, W. Won, J.-H. Kang, S. Lee, B.-G. Park, B. S. Ham, Y. Jo, F. Rotermund*, K.-J. Kim*, “Observation of spin-glass-like characteristics in ferromagnetic TbCo through energy-level-selective approach,” Nat. Commun. 13, 5530 (2022).

2. J. E. Bae, X. Mateos, M. Aguiló, F. Díaz, J. G. Ajates, C. Romero, J. R. V. de Aldana, F. Rotermund, “Multi-gigahertz mode-locked femtosecond Yb:KLuW waveguide lasers,” Photon. Res. 10, 2584 (2022). 

3. 3Y.-S. Lee, W. Yoon, H. Yun, M. Jazbinsek, I. C. Yu, F. Rotermund, O-P. Kwon, “New Organic 4-(4-Methoxystyryl)-1-methylpyridinium Crystals for Nonlinear Optical Applications,” Bull. Kor. Chem. Soc. 43, 1247 (2022). 

4. 4.T. G. Park, E.-T. Oh, S. Kim, Y. Ou, J. Moodera, H. Kim, F. Rotermund, "Ultrafast formation of quantized interlayer vibrations in Bi2Se3 by photoinduced strain waves," Opt. Express 30, 35988 (2022). 

5. S.-J. Kim†, J.-H. Seok†, I. C. Yu†, J. H. Lee†, W. T. Kim, B.-R. Shin, G.-E. Yoon, Y.-S. Lee, J. C. Kim, W. Yoon, H. Yun, M. Jazbinsek, S. K. Kwak*, F. Rotermund*, O-P. Kwon*, “Orthogonal molecular assembly: Eliminating intrinsic phonon modes in organic THz Generators,” Adv. Opt. Mater. 10, 2102654 (2022).

6. T. G. Park, J. H. Jeon, S.-H. Chun, S. Lee, F. Rotermund, "Ultrafast interfacial carrier dynamics and persistent topological surface states of Bi2Se3 in heterojunctions with VSe2," Commun. Phys. 5, 182 (2022). 

7. B.-R. Shin, S.-I. Kim, D. Kim, M. Jazbinsek, W. Yoon, H. Yun, I. C. Yu, F. Rotermund, O-Pil Kwon, “New N-pyrimidinyl stilbazolium chromophore and its crystalline states for second-order nonlinear optics,” Opt. Laser Tech. 156, 108454 (2022).

8. G.-E. Yoon, J.-H. Seok, U. Puc, B.-R. Shin, W. Yoon, H. Yun, D. Kim, I. C. Yu, F. Rotermund, M. Jazbinsek, O-P. Kwon, “Phonon-Suppressing Intermolecular Adhesives: Catechol-Based Broadband Organic THz Generators,” Adv. Sci. 9, 2201391 (2022).

9. J. E. Bae, T. Calmano, C. Kränkel, F. Rotermund, “Controllable dynamic single- and dual-channel graphene Q-switching in a beam-splitter-type channel waveguide laser," Laser Photon. Rev. 16, 2100501 (2022). (inside front cover)

10. K. Lee†, J. Park†, S. Lee, S. Baek, J. Park, F. Rotermund*, B. Min*, "Resonance-enhanced spectral funneling in Fabry-Perot resonators with a temporal boundary mirror," Nanophoton. 11, 2045 (2022).

11. S.-J. Kim, S.-I. Kim, M. Jazbinsek, W. Yoon, H. Yun, D. Kim, I. C. Yu, F. Rotermund, O-P. Kwon, "Design strategy of highly nonlinear optical orange-colored crystals with two electron-withdrawing groups," Adv. Photon. Res. 2100350 (2022).

12. R. Khazaeinezhad, S. H. Kassani, M. Ghasemi, Y. Cho, S. I. Im, D. I. Yeom, F. Rotermund, J. G Grote, E. Deleporte, I. Ledoux-Rak, K. Oh, “Third-order optical nonlinearity in nucleobase solid thin solid film and its application for ultrashort light pulse generation," J. Mater. Chem. C 10, 3517 (2022). 

2021    

1. S.-J. Kim†, B. J. Kang†, U. Puc†, W. T. Kim, M. Jasbinsek*, F. Rotermund*, O-P. Kwon*, " Highly nonlinear organic crystals for efficient terahertz wave generation, detection, and applications," Adv. Opt. Mater. 9, 2101019 (2021). (invited review)

2. T. G. Park, H. R. Na, S.-H. Chun, W. B. Cho, S. Lee, F. Rotermund, “Coherent control of interlayer vibrations in Bi2Se3 van der Waals thin-films,” Nanoscale 13, 19264 (2021).

3. I. H. Baek, H. W. Kim, H. S. Bark, K.-H. Jang, S. Park, J. Shin, Y. C. Kim, M. Kim, K. Y. Oang, K. Lee, F. Rotermund, N. Vinokurov, Y. U. Jeong, “Real-time ultrafast oscilloscope with a relativistic electron bunch train,” Nat. Commun. 12, 6851 (2021).

4. Z. Pan, L. Wang, J. E. Bae, F. Rotermund, Y. Wang, Y. Zhao, P. Loiko, X. Mateos, U. Griebner, V. Petrov, W. Chen “SWCNT-SA mode-locked Tm,Ho:LCLNGG laser,” Opt. Express 29, 40323 (2021). 

5. L. Wang, W. Chen, Y. Zhao, H. Yang, W. Jing, Z. Pan, H. Huang, J. Liu, J. E. Bae, F. Rotermund, P. Loiko, X. Mateos, Z. Wang, X. Xu, U. Griebner, V. Petrov, “Power-scalable sub-100-fs Tm laser at 2.08 um, High Power Laser Sci. Eng. 9, e50 (2021). 

6. J.-H. Seok†, D. Kim†, W. T. Kim†, S.-J. Kim, W. Yoon, G.-E. Yoon, I. C. Yu, M. Jazbinsek, S.-W. Kim, H. Yun, D. Kim, F. Rotermund*, O-P. Kwon*, "Organic THz Generators: A Design Strategy for Organic Crystals with Ultralarge Macroscopic Hyperpolarizability," Adv. Opt. Mater. 9, 2100324 (2021). 

7. J.-H. Seok, U. Puc, S.-J. Kim, W. Yoon, H. Yun, I. C. Yu, F. Rotermund, D. Kim, M. Jazbinsek, O-P. Kwon, “High-Density Organic Electro-Optic Crystals for Ultra-broadband THz Spectroscopy,” Adv. Opt. Mater. 9, 2100618 (2021). 

8. L. Wang, W. Chen, Z. Pan, P. Loiko, J. E. Bae, F. Rotermund, X. Mateos, U. Griebner, V. Petrov, "Sub-100 fs mode-locked Tm:CLTGG laser," Opt. Express 29, 31137 (2021). 

9. T. G. Park, B. K. Choi, J. Park, J. Kim, Y. J. Chang*, F. Rotermund*, "Interlayer coupling and ultrafast hot electron transfer dynamics in metallic VSe2/graphene van der Waals heterostructures", ACS Nano 15, 7756 (2021). 

10. S.-J. Kim†, I. C. Yu†, J.-A. Lee, W. T. Kim, M. Jazbinsek, W. Yoon, H. Yun, F. Rotermund*, O-P. Kwon*, “New benzothiazolium crystals with very large off-diagonal optical nonlinearity,” Dyes Pigm. 192, 109433 (2021). 

11. J. E. Bae, S. Y. Choi, C. Kränkel, K. Hasse, F. Rotermund, "Evanescent-field Q-switched Yb:YAG channel waveguide lasers with single- and double-pass pumping," Curr. Opt. Photon. 5, 180 (2021). 

12. J. J. Yoo, G. Seo, M. R. Chua, T. G. Park, Y. Lu, F. Rotermund, Y.-K. Kim, C. S. Moon, N. J. Jeon, J.-P. Correa-Baena, V. Bulovic, S. S. Shin, M. G. Bawendi, J. Seo, “Efficient perovskite solar cells via improved carrier management,” Nature 590, 587 (2021). (journal cover) 

13. J. Shin, H. W. Kim, S. Park, H. S. Bark, I. H. Baek, K. Y. Oang, K.-H. Jang, K. Lee, F. Rotermund, Y. U. Jeong, J. Kim, “Sub-10-fs timing for ultrafast electron diffraction with THz-driven streak camera,” Laser Photon. Rev. 15, 2000326 (2021). (front cover) 

14. K. R. Lee, H. J. Ma, F. Rotermund, D. K. Kim, Y. K. Park, “Non-resonant power-efficient directional Nd:YAG ceramic laser using scattering cavity,” Nat. Commun. 12, 1 (2021).   

 2020     

1. M.-H. Shin†, W. T. Kim†, S.-I. Kim, S.-J. Kim, I. C. Yu, S.-W. Kim, M. Jazbinsek, W. Yoon, H. Yun, F. Rotermund*, O-P. Kwon*, "Organic broadband THz generators optimized for efficient near-infrared optical pumping," Adv. Sci. 7, 2001738 (2020).

2. L. Wang, W. Chen, Y. Zhao, Y. Wang, Z. Pan, H. Lin, G. Zhang, Z. Lin, J. E. Bae, T. G. Park, F. Rotermund, P. Loiko, X. Mateos, M. Mero, U. Griebner, V. Petrov, “Single-walled carbon-nanotube saturable absorber assisted Kerr-lens mode-locked Tm:MgWO4 laser,” Opt. Lett. 45, 6142 (2020).

3. K. Lee†, J. Park†, B. J. Kang, W. T. Kim, H.-D. Kim, S. Baek, K. J. Ahn, B. Min*, F. Rotermund*, “Electrically controllable terahertz second-harmonic generation in GaAs,” Adv. Opt. Mater. 8, 2000359 (2020).

4. T. O. Buchmann, E. J. R. Kelleher, M. Jazbinsek, B. Zhou, J.-H. Seok, O-P. Kwon, F. Rotermund, P. U. Jepsen, “ High-power few-cycle THz generation at MHz repetition rates in an organic crystal,” APL Photon. 5, 106103 (2020). (featured article)

5. F. Yue, P. Loiko, M. Chen, J. M. Serres, Y. Wang, J. Li, L. Basyrova, E. Dunina, A. Kornienko, L. Fomicheva, S. Dai, Z. Chen, J. E. Bae, T. G. Park, F. Rotermund, V. Jambunathan, A. Lucianetti, T. Mocek, M. Aguiló, F. Díaz, U. Griebner, V. Petrov, X. Mateos, “Spectroscopy and diode-pumped laser operation of transparent Tm:Lu3Al5O12 ceramics produced by solid-state sintering,” Opt. Express 28, 28399 (2020).

6. D. Kim†, W. T. Kim†, J.-H. Seok, I. C. Yu, M. Jazbinsek, W. Yoon, H. Yun, D. Kim, F. Rotermund*, O-P. Kwon*, "Molecular salt crystals with bis(head-to-tail) interionic complementary assembly for efficient organic THz generators," J. Mater. Chem. C 8, 10078 (2020).  

7. K. Lee, S. C. Lee, W. T. Kim, J. Park, B. Min, F. Rotermund, “Terahertz generation from resonant photo-conductive antenna,” Curr. Opt. Photon. 4, 373 (2020). (editor's pick) 

8. J. E. Bae, X. Mateos, M. Aguiló, F. Díaz, J. R. V. de Aldana, C. Romero, H. Lee, F. Rotermund, “Transition of pulsed operation from Q-switching to continuous-wave mode-locking in a Yb:KLuW waveguide laser,” Opt. Express 28, 18027 (2020).

9. D. Kim†, W. T. Kim†, J.H. Han, J.-A. Lee, S.-H. Lee, B. J. Kang, M. Jazbinsek, W. Yoon, H. Yun, D. Kim, S. van Bezouw, J. Campo, W. Wenseleers, F. Rotermund*, O-P. Kwon*, “Wide-bandgap organic crystals: Enhanced optical-to-terahertz nonlinear frequency conversion at near-infrared pumping,” Adv. Opt. Mater. 8, 1902099 (2020).

10. T. O. Buchmann, E. J. R. Kelleher, K. J. Kaltenecker, B. Zhou, S.-H. Lee, O-P. Kwon, M. Jazbinsek, F. Rotermund, P. U. Jepsen, “MHz-repetition-rate, sub-mW, multi-octave THz wave generation in HMQ-TMS,” Opt. Express 28, 9631 (2020).

11. Y. Morova, J. E. Bae, F. Rotermund, A. Sennaroglu, “Laser micromachined zebra patterned graphene as a mode-locker with adjustable loss,” Opt. Lett. 45, 1826 (2020).

12. J.-A. Lee†, W. T. Kim†, M. Jazbinsek, D. Kim, S.-H. Lee, I. C. Yu, W. Yoon, H. Yun, F. Rotermund*, O-P. Kwon*, “X-shaped alignment of chromophores: Potential alternative for efficient organic terahertz generators,” Adv. Opt. Mater. 8, 1901921 (2020). (inside front cover)

13. H. W. Kim, N. A. Vinokurov, I. H. Baek, K. Y. Oang, M. H. Kim, Y. C. Kim, K.-H. Jang, K. Lee, S. H. Park, S. Park, J. Shin, J. Kim, F. Rotermund, S. Cho, T. Feurer, Y. U. Jeong, “Towards jitter-free ultrafast electron diffraction technology,” Nat. Photon. 14, 245 (2020).

14. A. Muti, F. Canbaz, M. Tonelli, J. E. Bae, F. Rotermund, V. Petrov, A. Sennaroglu, “Graphene mode-locked operation of Tm3+:YLF and Tm3+:KY3F10 lasers near 2.3 μm,” Opt. Lett. 45, 656 (2020). 

15. S.-I. Kim†, W. T. Kim†, J. H. Seok, M. Jazbinsek, W. Yoon, I. C. Yu, H. Yun, D. Kim, F. Rotermund*, O-P. Kwon*, “Organic σ-hole containing organic crystals with enhanced nonlinear optical response and efficient optical-to-THz frequency conversion,” Adv. Opt. Mater. 8, 1901840 (2020). 

16. Y. Zhao, L. Wang, Y. Wang, J. Zhang, P. Liu, X. Xu, Y. Liu, D. Shen, J. E. Bae, T. G. Park, F. Rotermund, X. Mateos, P. Loiko, Z. Wang, X. Xu, J. Xu, M. Mero, U. Griebner, V. Petrov, W. Chen, “SWCNT-SA mode-locked Tm:LuYO3 ceramic laser delivering 8-optical-cycle pulses at 2.05 μm,” Opt. Lett. 45, 459 (2020).

17. J. E. Bae, T. G. Park, E. Kifle, X. Mateos, M. Aguiló, F. Díaz, C. Romero, J. R. V. de Aldana, H. Lee, F. Rotermund, “Carbon nanotube Q-switched Yb:KLuW surface channel waveguide lasers," Opt. Lett. 45, 216 (2020).

18. M. Chen, P. Loiko, J. M. Serres, S. Veronesi, M. Tonelli, M. Aguiló, F. Díaz, S. Y. Choi, J. E. Bae, F. Rotermund, S. Dai, Z. Chen, U. Griebner, V. Petrov, X. Mateos, "Fluorite-type type Tm3+:KY3F10: A promising crystal for watt-level lasers at ∼1.9 μm," J. Alloys Comp. 813, 152176 (2020).

2019    

1. D. Chung, H. S. Park, F. Rotermund, B. Y. Kim, “Measurement of bending-induced birefringence in a hollow-core photonic crystal fiber,” Opt. Lett. 44, 5872 (2019).

2. M.-H. Shin+, W. T. Kim+, S.-I. Kim, S.-H. Lee, I. C. Yu, M. Jazbinsek, W. Yoon, H. Yun, D. Kim, F. Rotermund*, O-P. Kwon*, “Efficient gap-free broadband terahertz generators based on new organic Quinolinium single crystals,” Adv. Opt. Mater. 7, 1900953 (2019). (journal cover) 

3. G. Tanisali, I. Baylam, M. Tasci, J. E. Bae, F. Rotermund, U. Demirbas, A. Sennaroglu, “21-fs Cr:LiSAF laser mode-locked with a single-walled carbon nanotube saturable absorber,” Opt. Lett. 44, 4662 (2019). 

4. Y. Zhao, W. Chen, L. Wang, Y. Wang, Z. Pan, X. Dai, H. Yuan, H. Cai, Y. Zhang, J. E. Bae. T. G. Park, F. Rotermund, P. Loiko, J. M. Serres, X. Mateos, D. Shen, U. Griebner, V. Petrov, “Graphene mode-locked Tm, Ho-codoped crystalline garnet laser producing 70-fs pulses near 2.1 µm,” OSA Continuum 2, 2593 (2019). (editor's pick)

5. K. Lee, J. Park, J. Son, B. J. Kang, W. T. Kim, S. C. Lee, B. Min*, F. Rotermund*, “Electrical control of terahertz frequency conversion from time-varying surfaces,” Opt. Express 27, 12762 (2019).

6. S. Lee+,W. T. Kim+, J.-H. Kang, B. J. Kang, F. Rotermund*, Q-H. Park*, “Single-layered metasurfaces as spectrally tunable terahertz half- and quarter-waveplates," ACS Appl. Mater. Interfaces 11, 7655 (2019).

7. S. S. Shin, J. H. Suk, B. J. Kang, W. Yin, S. J. Lee, J. H. Noh, T. K. Ahn, F. Rotermund, I. S. Cho, S. I. Seok, “Energy-level engineering of the electron transporting layer for improving open-circuit voltage in dye and perovskite-based solar cells,” Energy Environ. Sci. 12, 958 (2019).

8. S.-I. Kim+, B. J. Kang+, C.-U. Jeong, M.-H. Shin, W. T. Kim, M. Jazbinsek, W. Yoon, H. Yun, D. Kim, F. Rotermund*, O-P. Kwon*, “Fluorinated organic electro‐optic Quinolinium crystals for THz wave generation,” Adv. Opt. Mater. 7, 1801495 (2019). (journal cover)

9. Y. Zhao, Y. Wang, W. Chen, Z. Pan, L. Wang, X. Dai, H. Yuan, Y. Zhang, H. Cai, J. E. Bae, S. Y. Choi, F. Rotermund, P. Loiko, J. M. Serres, X. Mateos, W. Zhou, D. Shen, U. Griebner, V. Petrov, “67-fs pulse generation from a mode-locked Tm,Ho:CLNGG laser at 2083 nm,” Opt. Express 27, 1922 (2019).

10. J. W. Kim, S. Y. Choi, J. E. Bae, M. H. Kim, Y. U. Jeong, E. Kifle, X. Mateos, M. Aguiló, F. Díaz, U. Griebner, V. Petrov, G.-H. Kim, F. Rotermund, "Comparative study of Yb:KYW planar waveguide lasers Q-switched by direct- and evanescent-field interaction with carbon nanotubes," Opt. Express 27, 1488 (2019).

11. M. Kowalczyk, X. Zhang, X. Mateos, S. Guo, Z. Wang, X. Xu, P. Loiko, J. E. Bae, F. Rotermund, J. Sotor, U. Griebner, V. Petrov, "Graphene and SESAM mode-locked Yb:CNGS lasers with self-frequency doubling properties," Opt. Express 27, 590 (2019). 

2018    

1. M.-H. Shin, S.-H. Lee, B. J. Kang, M. Jazbinsek, W. Yoon, H. Yun, F. Rotermund*, O-P. Kwon*, "Organic three-component single crystals with pseudo-isomorphic co-crystallization for nonlinear optics and THz photonics," Adv. Funct. Mater. 28, 1805257 (2018). (journal cover)

2. K. Lee, J. Son, J. Park, B. Kang, W. Jeon, F. Rotermund, B. Min, “Linear frequency conversion via sudden merging of meta-atoms in time-variant metasurfaces,” Nat. Photon. 12, 765 (2018).

3. Z. Pan, Y. Wang, Y. Zhao, M. Kowalczyk, J. Sotor, H. Yuan, Y. Zhang, X. Dai, H. Cai, J. E. Bae, S. Y. Choi, F. Rotermund, P. Loiko, J. M. Serres, X. Mateos, U. Griebner, V. Petrov, “Sub-80 fs mode-locked Tm,Ho-codoped disordered garnet crystal oscillator operating at 2081 nm,” Opt. Lett. 43, 5154 (2018).

4. E. Kifle, P. Loiko, J. R. V. de Aldana, C. Romero, A. Rodenas, S. Y. Choi, J. E. Bae, F. Rotermund, V. Zakharov, A. Veniaminov, M. Aquiló, F. Díaz, U. Griebner, V. Petrov, X. Mateos, "Passively Q-switched femtosecond-laser-written thulium waveguide laser based on evanescent field interaction with carbon nanotubes,” Photon. Res. 6, 971 (2018).

5. F. Rotermund, “Recent progress in broadband carbon nanotube saturable absorbers for ultrafast bulk solid-state lasers,” J. Kor. Phys. Soc. 73, 846 (2018). (overview article)

6. X. Jiang, S. Gross, M. J. Withford, H. Zhang, D.-I. Yeom, F. Rotermund, A. Fuerbach, “Low-dimensional nanomaterial saturable absorbers for ultrashort-pulsed waveguide lasers,” Opt. Mater. Express 8, 3055 (2018).

7. Y. Wang, Y. Zhao, Z. Pan, J. E. Bae, S. Y. Choi, F. Rotermund, P. Loiko, J. M. Serres, X. Mateos, H. Yu, H. Zhang, M. Mero, U. Griebner, V. Petrov, “78 fs SWCNT-SA mode-locked Tm:CLNGG disordered garnet crystal laser at 2017 nm,” Opt. Lett. 43, 4268 (2018).

8. C.-U. Jeong+, B. J. Kang+, S.-H. Lee, S.-C. Lee, W. T. Kim, M. Jazbinsek, W. Yoon, H. Yun, D. Kim, F. Rotermund*, O-P. Kwon*, “Yellow-colored electro-optic crystals as intense terahertz wave sources,” Adv. Funct. Mater. 28, 1801143 (2018). (journal cover)

9. Z. Pan, Y. Wang, Y. Zhao, H. Yuan, X. Dai, H. Cai, J. E. Bae, S. Y. Choi, F. Rotermund, X. Mateos, J. M. Serres, P. Loiko, U. Griebner, V. Petrov, "Generation of 84-fs pulses from a mode-locked Tm:CNNGG disordered garnet crystal laser," Photon. Res. 6, 800 (2018).

10. S.-C. Kim, J. Kim, H. E. Lee, B. J. Kang, F. Rotermund, S.-J. Kim, "The crystal structure and phase transitions of LiBaPO4," Solid. Stat. Sci. 83, 76 (2018).

11. J.-H. Kang, S.-J. Lee, B. J. Kang, W. T. Kim, F. Rotermund, Q-H. Park, "Anomalous wavelength scaling of tightly coupled terahertz metasurfaces," ACS Appl. Mater. Interfaces 10, 19331 (2018).

12. J. W. Kim, S. Y. Choi, W. T. Kim, B. J. Kang, W. B. Cho, G.-H. Kim, F. Rotermund, "550-MHz carbon nanotube mode-locked femtosecond Cr:YAG laser," Chin. Opt. Lett. 16, 061404 (2018). (highlights & cover story) 

13. S.-C. Lee+, B. J. Kang+, J.-A. Lee, S.-H. Lee, M. Jazbinsek, W. Yoon, H. Yun, F. Rotermund*, O-P. Kwon*, “Single crystals based on hydrogen-bonding mediated cation-anion assembly with extremely large optical nonlinearity and their application for intense THz wave generation,” Adv. Opt. Mater. 6, 1701258 (2018). (inside front cover)

14. B. Boulanger, S. Jiang, S. Mirov, J. Nilsson, A. Petersen, F. Rotermund, S. Taccheo, T. Taira, "Feature issue introduction: Advanced Solid-State Lasers 2017," Opt. Mater. Express 8, 1246 (2018). 

15. B. J. Kang, S.-H. Lee, W. T. Kim, S.-C. Lee, K. Lee, G. Benacchio, G. Montemezzani, M. Jazbinsek*, O-P. Kwon*, F. Rotermund*, "New class of efficient terahertz generators: Effective terahertz spectral filling by complementary tandem configuration of nonlinear organic crystals," Adv. Funct. Mater. 28, 1707195 (2018). (inside front cover)

16. S. Y. Choi, T. Calmano, F. Rotermund*, C. Kränkel*, “2-GHz carbon nanotube mode-locked Yb:YAG channel waveguide laser,” Opt. Express 26, 5140 (2018).

17. E. Kifle, X. Mateos, P. Loiko, S.Y. Choi, J. E. Bae, F. Rotermund, M. Aguiló, F. Díaz, U. Griebner, V. Petrov, “Tm:KY1-x-yGdxLuy(WO4)2 planar waveguide laser passively Q-switched by single-walled carbon nanotubes,” Opt. Express 26, 4961 (2018).

18. S.-J. Lee+, B. J. Kang+, M.-H. Shin, S.-C. Lee, S.-H. Lee, M. Jazbinsek, H. Yun, D. Kim, F. Rotermund*, O-P. Kwon*, “Efficient optical-to-THz conversion organic crystals with simultaneous electron withdrawing and donating Halogen substituents,” Adv. Opt. Mater. 6, 1700930 (2018). (journal cover)    

2017  

1. K. J. Ahn, J. Y. Gwak, B. J. Lee, S. Y. Choi, M. H. Kim, I. H. Baek, Y. U. Jeong, F. Rotermund, "Wavelength and fluence dependent third-order optical nonlinearity of mono- and multi-layer graphene," Appl. Opt. 56, 9920 (2017).  

2. J.-Y. Choi, S.-J. Lee, S.-C. Lee, C.-U. Jeong, M. Jazbinsek, H. Yun, B. J. Kang, F. Rotermund, O-P. Kwon, “Quinolinium single crystals with a high optical nonlinearity and unusual out-of-plane polar axis,” J. Mater. Chem. C 5, 12602, (2017).

3. X. Mateos, P. Loiko, S. Y. Choi, F. Rotermund, M. Aguiló, F. Díaz, U. Griebner, V. Petrov, “Single-walled carbon nanotubes oust graphene and semiconductor saturable absorbers in Q-switched solid-state lasers at 2 μm,” Laser Phys. Lett. 14, 095801 (2017).

4. S.-H. Lee, J. Lu, J.-H. Han, C.-U. Jeong, S.-C. Lee, X. Li, M. Jazbinsek, W. Yoon, H. Yun, B. J. Kang, F. Rotermund, K. A. Nelson, O-P. Kwon, “Benzothiazolium single crystals: A new class of nonlinear optical crystals with efficient THz wave generation,” Adv. Mater. 29, 1701748 (2017). (inside back cover) 

5. Y. Wang, W. Chen, M. Mero, L. Zhang, H. Lin, Z. Lin, G. Zhang, F. Rotermund, Y. J. Cho, P. Loiko, X. Mateos, U. Griebner, V. Petrov, “Sub-100 fs Tm:MgWO4 laser at 2017 nm mode-locked by a graphene saturable absorber,” Opt. Lett. 42, 3076 (2017). (editor's pick)

6. K. J. Ahn, F. Rotermund, “Terahertz optical bistability of graphene in thin layers of dielectrics,” Opt. Express 25, 8484 (2017).

7. S.-H. Lee+, B. J. Kang+, B.-W. Yoo, S.-C. Lee, S.-J. Lee, M. Jazbinsek, H. Yun, F. Rotermund*, O-P. Kwon*, “Terahertz phonon mode engineering of highly efficient organic terahertz generators,” Adv. Funct. Mater. 27, 1605583 (2017). (journal cover)

8.  C. Kim, D. Kwon, D. Kim, S. Choi, S. Cha, K. Choi, D. Yeom, F. Rotermund, and J. Kim, “Robust, low-noise, polarization-maintaining mode-locked Er-fiber laser with a planar lightwave circuit (PLC) device as a multi-functional element,” Opt. Lett. 42, 1472 (2017).

9. P. Loiko, J. M. Serres, X. Mateos, M. Aguiló, F. Díaz, L. Zhang, Z. Lin, H. Lin, G. Zhang, K. Yumashev, V. Petrov, U. Griebner, Y. Wang, S. Y. Choi, F. Rotermund, W. Chen, “Monoclinic Tm3+:MgWO4: a promising crystal for continuous-wave and passively Q-switched laser at ~2 μm,” Opt. Lett. 42, 1177 (2017).

10. E. Kifle, X. Mateos, J. R. Vazquez De Aldana, A. Rodenas, P. Loiko, S. Y. Choi, F. Rotermund, U. Griebner, V. Petrov, M. Aguiló, F. Díaz, “Femtosecond-laser written Tm:KLu(WO4)2 waveguide lasers,” Opt. Lett. 42, 1169 (2017).

11. P. Peranantham, G. H. Park, K. Kim, K. J. Ahn, C. K. Hwangbo, J. Lee, F. Rotermund, “Efficiency enhancement of a single-junction GaAs solar cell with ZnO nanrod arrays as an antireflection layer,” J. Nanosci. Nanotech. 17, 4279 (2017).

12. I. H. Baek+, J. M. Hamm+, K. J. Ahn+, B. J. Kang, S. S. Oh, S. Bae, S. Y. Choi, B. H. Hong, D.-I. Yeom, B. Min, O. Hess, Y. U. Jeong, F. Rotermund, “Boosting the terahertz nonlinearity of graphene by orientation disorder,” 2D Mater. 4, 025035 (2017).

13. H. J. Choi+, I. H. Baek+, B. J. Kang, H.-D. Kim, S. S. Oh, J. Hamm, A. Pusch, J. Park, K. Lee, J. Son, Y. U. Jeong, O. Hess, F. Rotermund*, B. Min*, “Control of terahertz nonlinear transmission with electrically gated graphene metadevices," Sci. Rep. 7, 42833 (2017).

14. K. N. Gorbachenya, V. E. Kisel, A. S. Yasukevich, M. B. Prudnikova, V. V. Maltsev, N. I. Leonyuk, S. Y. Choi, F. Rotermund, N. V. Kuleshov, “Passively Q-switched Er,Yb:GdAl3(BO3)4 laser with single-walled carbon nanotube based saturable absorber,” Laser Phys. Lett. 14, 035802 (2017).

15. R. Khazaeinezhad, S. H. Kassani, B. Paulson, H. Jeong, J. Gwak, F. Rotermund*, D.-I. Yeom*, K. Oh*, “Ultrafast nonlinear optical properties of thin-solid DNA film and their application as a saturable absorber in femtosecond mode-locked fiber laser," Sci. Rep. 7, 41480 (2017).

16. S.-C. Lee+, B. J. Kang+, M.-J. Koo, S.-H. Lee, J.-H. Han, J.-Y. Choi, W. T. Kim, M. Jazbinsek, H. Yun, D. Kim, F. Rotermund*, O-P. Kwon*, “New electro-optic salt crystals for efficient terahertz wave generation by direct pumping at Ti:sapphire wavelength,” Adv. Opt. Mater. 5, 1600758 (2017). (frontispiece)

17. T. K. Nguyen, W. T. Kim, B. J. Kang, H. S. Bark, K. Kim, J. Lee, I. Park, T.-I. Jeon, F. Rotermund, “Photoconductive dipole antennas for efficient terahertz receiver,” Opt. Commun. 383, 50 (2017).

18. J. Ko, H. Jeong, S. Y. Choi, F. Rotermund, D.-I. Yeom, B. Y. Kim, “Single-walled carbon nanotubes on side polished fiber as a universal saturable absorber for various laser output states,” Curr. Appl. Phys. 17, 37 (2017).

2016    

1. K. Miyamoto+, B. J. Kang+, W. T. Kim, Y. Sasaki, H. Niinomi, K. Suizu, F. Rotermund*, T. Omatsu*, “Highly intense monocycle terahertz vortex generation by utilizing a Tsurupica spiral phase plate,” Sci. Rep. 6, 38880 (2016).

2. Y. H. Park, M. H. Kim, S. B. Kim, H. J. Jung, Y. H. Ahn, J.-Y. Park, F. Rotermund*, S. W. Lee*, “Enhanced nucleation of high-k dielectrics on graphene by atomic layer deposition," Chem. Mater. 28, 7268 (2016).

3. P. Loiko, X. Mateos, S. Y. Choi, F. Rotermund, J. M. Serres, M. Aguiló, F. Díaz, K. Yumashev, U. Griebner, V. Petrov, “Vibronic thulium laser at 2131 nm Q-switched by single-walled carbon nanotubes,” J. Opt. Soc. Am. B 33, D19 (2016).

4. J. Gene, N. H. Park, H. S. Jeong, S. Y. Choi, F. Rotermund, D.-I. Yeom, B. Y. Kim, “Optically controlled in-line graphene saturable absorber for the manipulation of pulsed fiber laser operation,” Opt. Express 24, 12301 (2016).

5. W. B. Cho, S. Y. Choi, C. Zhu, M. H. Kim, J. W. Kim, J. S. Kim, H. J. Park, D. H. Shin, M. Y. Jung, F. Wang, F. Rotermund, “Graphene mode-locked femtosecond Cr2+:ZnS laser with ~300 nm tuning range,” Opt. Express 24, 20774 (2016).

6. H. Jeong, S. Y. Choi, F. Rotermund, K. Lee, and D.-I. Yeom, “All-Polarization Maintaining Passively Mode-Locked Fiber Laser Using Evanescent Field Interaction With Single-Walled Carbon Nanotube Saturable Absorber,” J. Lightwave Technol. 34, 3510 (2016).

7. S.-H. Lee, S.-J. Lee, M. Jazbinsek, B. J. Kang, F. Rotermund, and O.-P. Kwon, “Electro-optic crystals grown in confined geometry with optimal crystal characteristics for THz photonic applications,” CrystEngComm. 18, 7311 (2016).

8. K-H. Lee, S.-H. Lee, H. Yun, M. Jazbinsek, J. W. Kim, F. Rotermund, O-P. Kwon, “Multi-functional supramolecular building blocks with hydroxy piperidino groups: new opportunities for developing nonlinear optical ionic crystals,” CrystEngComm. 18, 5832 (2016).

9. S. Han, J.-Y. Kim, T. Kang, Y.-M. Bahk, J. Rhie, B. J. Kang, Y. S. Kim, J. Park, W. T. Kim, H. Jeon, F. Rotermund, D.-S. Kim, “Colossal terahertz nonlinearity in Angstrom- and nanometer-sized gaps,” ACS Photon. 3, 1440 (2016).

10. M. H. Kim, T. Calmano, S. Y. Choi, B. J. Lee, I. H. Baek, K. J. Ahn, D.-I. Yeom, C. Kränkel, F. Rotermund, “Monolayer graphene coated Yb:YAG channel waveguides for Q-switched laser operation,” Opt. Mater. Express 6, 2468 (2016).

11. S.-H. Lee, G.-H. Lee, K.-H. Lee, M. Jazbinsek, B. J. Kang, F. Rotermund, O-P. Kwon, “In-situ Tailor-made Additives for Molecular Crystals: A Simple Route to Morphological Crystal Engineering,” Cryst. Growth Des. 16, 3555 (2016).

12. J.-Y. Kim, B. J. Kang, Y.-M. Bahk, Y. S. Kim, J. Park, W. T. Kim, J. Rhie, S. Han, H. Jeon, C.-H. Park, F. Rotermund, D.-S. Kim, "Tunnelling current-voltage characteristics of Angstrom gaps measured with terahertz time-domain spectroscopy," Sci. Rep. 6, 29103 (2016).

13. H. Jeong, S. Y. Choi, M. H. Kim, F. Rotermund, Y.-H. Cha, D.-Y. Jeong, S. B. Lee, K. Lee, D.-I. Yeom, "All-fiber Tm-doped soliton laser oscillator with 6 nJ pulse energy based on evanescent field interaction with monolayer graphene saturable absorber," Opt. Express 24, 14153 (2016).

14. R. Lan, P. Loiko, X. Mateos, Y. Wang, J. Li, Y. Pan, S. Y. Choi, M. H. Kim, F. Rotermund, A. Yasukevich, K. Yumashev, U. Griebner, V. Petrov, "Passive Q-switching of microchip lasers based on Ho:YAG ceramics," Appl. Opt. 55, 4877 (2016).

15. B. J. Kang, I. H. Baek, S.-H. Lee, W. T. Kim, S.-J. Lee, Y. U. Jeong, O-P. Kwon, F. Rotermund, “Highly nonlinear organic crystal OHQ-T for efficient ultra-broadband terahertz wave generation beyond 10 THz,” Opt. Express 24, 11054 (2016). 

16. B. Lee, H. Kwon, S. Kim, F. Rotermund, “Natural silk protein as a new broadband nonlinear optical material,” Opt. Mater. Express 6, 993 (2016). 

17. S.-H. Lee, M.-J. Koo, K.-H. Lee, M. Jazbinsek, B.-J. Kang, F. Rotermund, O-P. Kwon, "Quinolium-based organic electro-optic crystals: Crystal characteristics in solvent mixtures and optical properties in the terahertz range," Mater. Chem. Phys. 169, 62 (2016).

2015    

1. M.-J. Koo, S.-H. Lee, H. Yun, J. W. Kim, F. Rotermund, O-P. Kwon, "New electro-optic N-methylquinolinium crystals with naphthalene-1-sulfonate," Bull. Kor. Chem. Soc. 36, 2920 (2015).

2. B. Park, B. J. Lee, S. R. Dugasani, Y. Cho, C. Kim, M. Seo, T. Lee, Y. M. Jhon, J. Choi, S. Lee, S. H. Park, S. C. Jun, D.-I Yeom, F. Rotermund*, J. H. Kim*, “Enhanced nonlinear optical characteristics of copper-ion-doped double crossover DNAs,” Nanoscale 7, 18089 (2015).

3. J.-Y. Kim+, B. J. Kang+, J. Park, Y.-M. Bahk, W. T. Kim, J. Rhie, H. Jeon, F. Rotermund, D.-S. Kim, “Terahertz quantum plasmonics of nanoslot antennas in nonlinear regime,” Nano Lett. 15, 6683 (2015).

4. C. Kim, D. Kim, Y. J. Cheong, D. Kwon, S. Y. Choi, H. Jeong, S. J. Cha, J.-W. Lee, D.-I. Yeom, F. Rotermund, J. Kim, "300-MHz-repetition-rate, all-fiber, femtosecond laser mode-locked by planar lightwave circuit-based saturable absorber,” Opt. Express 23, 26234 (2015).

5. Y.-M. Bahk+, B. J. Kang+, Y. S. Kim, J.-Y. Kim, W. T. Kim, T. Y. Kim, T. Kang, J. Rhie, S. Han, C.-H. Park, F. Rotermund*, D.-S. Kim*, “Electromagnetic saturation of angstrom-sized quantum barriers at terahertz frequencies,” Phys. Rev. Lett. 115, 125501 (2015). (editor's suggestion & cover article)

6. N. H. Park, H. Jeong, S. Y. Choi, M. H. Kim, F. Rotermund, D.-I. Yeom, "Monolayer graphene saturable absorbers with strongly enhanced evanescent-field interaction for ultrafast fiber laser mode-locking," Opt. Express 23, 19806 (2015).

7. K. J. Ahn, Y.-M. Bahk, D.-S. Kim, J. Kyoung, F. Rotermund, “Ultrasensitive molecular absorption detection using metal slot antenna arrays,” Opt. Express 23, 19047 (2015).

8. S.-H. Lee, B.W. Yoo, M. Jazbinsek, B.-J. Kang, F. Rotermund, O-P. Kwon, “Organic ionic electro-optic crystals grown by specific interactions on templates for THz wave photonics,” CrystEngComm. 17, 4781 (2015).

9. E. J. Lee+, S. Y. Choi+, H. Jeong+, N. H. Park, W. Yim, M. H. Kim, J.-K. Park, S. Son, S. Bae, S. J. Kim, Y. H. Ahn, K. J. Ahn, B. H. Hong, J.-Y. Park, F. Rotermund*, D.-I. Yeom*, “Active control of all-fibre graphene devices with electrical gating,” Nat. Commun. 6, 6851 (2015).

10. J.-S. Kim, S.-H. Lee, M. Jazbinsek, H. Yun, J. Kim, Y. S. Lee, J. W. Kim, F. Rotermund, O-P. Kwon, “New phenolic N-methylquinolinium single crystals for second-order nonlinear optics,” Opt. Mater. 45, 136 (2015).

11. S.-H. Lee, B.-J. Kang, J.-S. Kim, B.-W. Yoo, J.-H. Jeong, K.-H. Lee, M. Jazbinsek, J. W. Kim, H. Yun, J. Kim, Y. S. Lee, F. Rotermund*, O-P. Kwon*, “New Acentric Core Structure for Organic Electro-Optic Crystals Optimal for Efficient Optical-to-THz Conversion,” Adv. Opt. Mater. 3, 756 (2015).

12. S. Y. Choi, T. Calmano, M. H. Kim, D.-I. Yeom, C. Kränkel, G. Huber, F. Rotermund, “Q-switched operation of a femtosecond-laser-inscribed Yb:YAG channel waveguide laser using carbon nanotubes,” Opt. Express 23, 7999 (2015).

13. J. W. Kim, S. Y. Choi, S. Aravazhi, M. Pollnau, U. Griebner, V. Petrov, S. Bae, K. J. Ahn, D.-I. Yeom, F. Rotermund, “Graphene Q-switched Yb:KYW planar waveguide laser,” AIP Adv. 5, 017110 (2015).

2014

1. V. Aleksandrov, A. Gluth, V. Petrov, I. Buchvarov, S. Y. Choi, M. H. Kim, F. Rotermund, X. Mateos, F, Díaz, U. Griebner, “Tm,Ho:KLu(WO4)2 laser mode-locked near 2 μm by single-walled carbon nanotubes,” Opt. Express 22, 26872 (2014).

2. H. Jeong, S. Y. Choi, F. Rotermund, Y.-H. Cha, D.-Y. Jeong, D.-I. Yeom “All-fiber mode-locked laser oscillator with pulse energy of 34 nJ using a carbon nanotube saturable absorber,” Opt. Express 22, 22667 (2014).

3. S. Y. Choi, J. W. Kim, M. H. Kim, D.-I. Yeom, B. H. Hong, X. Mateos, M. Aguiló, F. Díaz, V. Petrov, U. Griebner, F. Rotermund, “Carbon nanostructure-based saturable absorber mirror for a diode-pumped 500-MHz femtosecond Yb:KLu(WO4)2 laser,” Opt. Express 22, 15626 (2014).

4. T. K. Nguyen, F. Rotermund, I. Park, “A traveling-wave stripline dipole antenna on a substrate lens at terahertz frequency,” Curr. Appl. Phys. 14, 998 (2014).

5. Y. Zhang, V. Petrov, U. Griebner, X. Zhang, S. Y. Choi, J. Y. Gwak, F. Rotermund, X. Mateos, H. Yu, H. Zhang, J. Liu, “90-fs diode-pumped Yb:CLNGG laser mode-locked using single-walled carbon nanotube saturable absorber,” Opt. Express 22, 5635 (2014).

6. T. K. Nguyen, S. Kim, F. Rotermund, I. Park, “Design of a wideband continuous-wave photomixer antenna for terahertz wireless communication systems,” J. Electromag. Waves Appl. 28, 976 (2014).

7. I. H. Baek, B. J. Kang, Y. U. Jeong, F. Rotermund, "Diffraction-limited high-power single-cycle terahertz pulse generation in prism-cut LiNbO3 for precise terahertz applications,” J. Opt. Soc. Kor. 18, 60 (2014). 

8. B. J. Kang, I. H. Baek, J. H. Jeong, J. S. Kim, S. H. Lee, O-P. Kwon, F. Rotermund, “Characteristics of efficient few-cycle terahertz radiation generated in as-grown nonlinear organic single crystals,” Curr. Appl. Phys. 14, 403 (2014).

9. H. Yang, H. Kim, J. Shin, C. Kim, S. Y. Choi, G. H. Kim, F. Rotermund, J. Kim, “Gigahertz repetition rate, sub-femtosecond timing jitter optical pulse train directly generated from a mode-locked Yb:KYW laser,” Opt. Lett. 39, 56 (2014).

10. S. Y. Choi, H. Jeong, B. H. Hong, F. Rotermund*, D.-I. Yeom*, “All-fiber dissipative soliton laser with 10.2 nJ pulse energy using an evanescent field interaction with graphene saturable absorber,” Laser Phys. Lett. 11, 015101 (2014).

2013

1. J. W. Kim, S. Y. Choi, D.-I. Yeom, S. Aravazhi, M. Pollnau, U. Gruebner, V. Petrov, F. Rotermund, “Yb:KYW planar waveguide laser Q-switched by evanescent-field interaction with carbon nanotubes,” Opt. Lett. 38, 5090 (2013).

2. J.-S. Kim, J.-H. Jeong, H. Yun, M. Jazbinsek, J. W. Kim, F. Rotermund, O-P. Kwon, “Crystal engineering of Acentric Styryl Quinolinium crystals with strongly Hydrogen-bonded Phenolic anions," Cryst. Growth Des. 13, 5085 (2013).

3. H. Jeong, S. Y. Choi, F. Rotermund, D.-I. Yeom, “Pulse width shaping of passively mode-locked soliton fiber laser via polarization control in carbon nanotube saturable absorber,” Opt. Express 21, 27011 (2013).

4. J.-H. Jeong+, B.-J. Kang+, J.-S. Kim, M. Jazbinsek, S.-H. Lee, S.-C. Lee, I.-H. Baek, H. Yun, J. Kim, Y. S. Lee, J.-H. Lee, J. H. Kim, F. Rotermund*, O-P. Kwon*, “High-power broadband organic THz generator,” Sci. Rep. 3, 3200 (2013).

5. M. Galceran, M. C. Pujol, J. J. Carvajal, X. Mateos, P. Formentin, J. Pallares, L. Marsal, K. Park, F. Rotermund, K. Kim, A. Magdalena, F. Díaz, “New microarchitectures of (Er,Yb):Lu2O3 nanocrystals embedded in PMMA: synthesis, structural characterization and luminescent properties,” Nanoscale Res. Lett. 8, 385 (2013).

6. S. D. D. D. Cafiso, E. Ugolotti, A. Schmidt, V. Petrov, U. Griebner, A. Agnesi, W. B. Cho, Y. G. Zhang, S. Y. Choi, F. Rotermund, G. Reali, F. Pirzio, “Sub-50-fs mode-locking of the Cr:YAG laser using SWCNT-SA,” Laser Phys. Lett. 10, 085801 (2013).

7. K. Seger, N. Meiser, S. Y. Choi, B. H. Jung, D.-I. Yeom, F. Rotermund, O. Okhotnikov, F. Laurell, V. Pasiskevicius, "Carbon nanotube mode-locked optically-pumped semiconductor disk laser," Opt. Express 21, 17806 (2013).

8. H. Jeong, S. Y. Choi, E. I. Jeong, S. J. Cha, F. Rotermund, D.-I. Yeom, "Ultrafast mode-locked fiber laser using a waveguide-type saturable absorber based on single-walled carbon nanotubes," Appl. Phys. Express 6, 052705 (2013).

9. S. D. D. Cafiso, E. Ugolotti, A. Schmidt, V. Petrov, U. Griebner, A. Agnesi, W. B. Cho, B. H. Jung, F. Rotermund, S. Bae, B. H. Hong, G. Reali, F. Pirzio, “Sub-100-fs Cr:YAG laser mode-locked by monolayer graphene saturable absorber,” Opt. Lett. 38, 1745 (2013).

10. I. H. Baek, K. J. Ahn, B. J. Kang, S. Bae, B. H. Hong, D.-I. Yeom, K. Lee, Y. U. Jeong, F. Rotermund, "Terahertz transmission and sheet conductivity of randomly stacked multi-layer graphene," Appl. Phys. Lett. 102, 191109 (2013).

11. D. J. Park, J. T. Hong, J. K. Park, S. B. Choi, B. H. Son, F. Rotermund, S. Lee, K. J. Ahn, D. S. Kim, Y. H. Ahn, “Resonant transmission of terahertz waves through metallic slot antennas on various dielectric substrates,” Curr. Appl. Phys. 13, 753 (2013).

12. J. W. Kim, S. Y. Choi, B. H. Jung, D.-I. Yeom, F. Rotermund, "Applicability of graphene flakes as saturable absorber for bulk laser mode-locking," Appl. Phys. Express 6, 032704 (2013). 

13. M. N. Cizmeciyan, J. W. Kim, S. Bae, B. H. Hong, F. Rotermund*, A. Sennaroglu*, “Graphene mode-locked femtosecond Cr:ZnSe laser at 2500 nm,” Opt. Lett. 38, 341 (2013).

14. H. W. Lee, K. Lee, S. Cho, J. Kiran A., S. Lee, H. Lim, K. Kim, V. Pasiskevicius, F. Rotermund, "Evaluation of the third-order optical nonlinearity of Au:SiO2 nanocomposites in the off-resonant spectral region," Opt. Commun. 286, 347 (2013).

2012

1. H.-W. Yang, C. Kim, S. Y. Choi, G.-H. Kim, Y. Kobayashi, F. Rotermund, J. Kim, “1.2-GHz repetition rate, diode-pumped femtosecond Yb:KYW laser mode-locked by a carbon nanotube saturable absorber mirror,” Opt. Express 20, 29518 (2012).

2. E. Ugolotti, A. Schmidt, V. Petrov, J. W. Kim, D.-I. Yeom, F. Rotermund*, S. Bae, B. H. Hong, A. Agnesi, C. Fiebig, G. Erbert, X. Mateos, M. Aguiló, F. Díaz, U. Griebner*, “Graphene mode-locked femtosecond Yb:KLuW laser,” Appl. Phys. Lett. 101, 161112 (2012).

3. I. Baylam, S. Ozharar, H. Cankaya, S. Y. Choi, K. Kim, F. Rotermund, U. Griebner, V. Petrov, A. Sennaroglu, “Energy scaling of a carbon nanotube saturable absorber mode-locked femtosecond bulk laser,” Opt. Lett. 37, 3555 (2012).

4. A. Schmidt, S. Y. Choi, D.-I. Yeom, F. Rotermund, X. Mateos, M. Segura, F. Díaz, G. Steinmeyer, V. Petrov, U. Griebner, “Femtosecond pulses near 2 μm from a Tm:KLuW laser mode-locked by a single-walled carbon nanotube saturable absorber,” Appl. Phys. Express 5, 092704 (2012).

5. F. Rotermund, W. B. Cho, S. Y. Choi, I. H. Baek, J. H. Yim, S. Lee, A. Schmidt, G. Steinmeyer, U. Griebner, D.-I. Yeom, K. Kim, V. Petrov, “Mode-locking of solid-state lasers by single-walled carbon-nanotube based saturable absorbers,” Quantum Electron. 42, 663 (2012).

6. Y. Kim, N. D. Lam, K. Kim, S. Kim, F. Rotermund, H. Lim, J. Lee, “Novel anti-reflection technology for GaAs single-junction solar cells using surface patterning and Au nanoparticles," J. Nanosci. Nanotechnol. 12, 5497 (2012).

7. B. P. Nguyen, K. Kim, F. Rotermund, H. Lim, “Transmission resonance induced by a δ-like defect in the Fano-Anderson model with two Fano defects,” Phys. Status Solidi B 249, 1765 (2012).

8. C. S. Jun, S. Y. Choi, F. Rotermund, B. Y. Kim, D.-I. Yeom, "Toward higher-order passive harmonic mode-locking of soliton fiber laser," Opt. Lett. 37, 1862 (2012).

9. M. H. Doan, S. Kim, J. J. Lee, H. Lim, F. Rotermund, K. Kim, “Influence of laser lift-off on optical and structural properties of InGaN/GaN vertical blue light emitting diodes,” AIP Adv. 2, 022122 (2012).

10. S. Y. Choi, D. K. Cho, Y.-W. Song, K. Oh, K. Kim, F. Rotermund, D.-I. Yeom, "Graphene-filled hollow optical fiber saturable absorber for soliton fiber laser mode-locking," Opt. Express 20, 5652 (2012).

11. E. W. Barrera, M. C. Pujol, C. Cascales, C. Zaldo, K. H. Park, S. B. Choi, F. Rotermund, J. J. Carvajal, X. Mateos, M. Aguiló, F. Díaz, “Spectroscopic characterization of sol-gel synthesized Tm:Lu2O3 nanocrystals,” Appl. Phys. B 106, 409 (2012).

12. A. Schmidt, P. Koopmann, G. Huber, P. Fuhrberg, S. Y. Choi, D.-I. Yeom, F. Rotermund, V. Petrov, U. Griebner, “175 fs Tm:Lu2O3 laser at 2.07 μm mode-locked using single-walled carbon nanotubes,” Opt. Express 20, 5313 (2012).

13. I. H. Baek, H. W. Lee, S. Bae, B. H. Hong, Y. H. Ahn, D.-I. Yeom, F. Rotermund, “Efficient mode-locking of sub-70 fs Ti:sapphire laser by graphene saturable absorber,” Appl. Phys. Express 5, 032701 (2012).

14. A. Agnesi, A. Greborio, F. Pirzio, G. Reali, E. Ugolotti, S. Y. Choi, F. Rotermund, U. Griebner, V. Petrov, “Femtosecond Nd:glass lasers pumped by single-mode laser diodes and mode locked with carbon nanotube or semiconductor saturable absorber mirrors,” IEEE J. Sel. Top. Quantum Electron. 18, 74 (2012).

15. H. Iliev, I. Buchvarov, S. Y. Choi, K. Kim, F. Rotermund, U. Griebner, V. Petrov, “Steady state mode-locking of a 1.34 μm Nd:YVO4 laser using a single-walled carbon nanotube saturable absorber,” Appl. Phys. B 106, 1 (2012).

16. B. J. Rudresha, B. R. Bhat, D. Ramakrishna, J. K. Anthony, H. W. Lee, F. Rotermund, “Nonlinear optical study of palladium Schiff base complex using femtosecond differential optical Kerr gate and Z-scan techniques,” Opt. Laser Technol. 44, 1180 (2012).

17. J.-Y. Seo, S.-H. Lee, M. Jazbinsek, H. Yun, J.-T. Kim, I.-H. Baek, F. Rotermund, O-P. Kwon, “New Thiolated Nitrophenylhydrazone crystals for Nonlinear Optics,” Cryst. Growth Des. 20, 313 (2012).

18. A. Agnesi, F. Pirzio, E. Ugolotti, S. Y. Choi, D.-I. Yeom, F. Rotermund, “Femtosecond single-mode diode-pumped Cr:LiSAF laser mode-locked with single-walled carbon nanotubes,” Opt. Commun. 285, 742 (2012).

19. P.-J. Kim, J.-H. Jeong, M. Jazbinsek, S.-B. Choi, I.-H. Baek, J.-T. Kim, F. Rotermund, H. Yun, Y. S. Lee, P. Guenter, O-P. Kwon, “Highly efficient organic THz generator pumped at near infrared: Quinolinium single crystals,” Adv. Funct. Mater. 22, 200 (2012).

20. J. T. Hong, D. J. Park, J. Y. Moon, S. B. Choi, J. K. Park, F. Rotermund, J.-Y. Park, S. Lee, Y. H. Ahn, “Terahertz wave applications of single-walled carbon nanotube films with high shielding effectiveness,” Appl. Phys. Express 5, 015102 (2012).

21. S. Kim, K. Kim, F. Rotermund, H. Lim, "Nonreciprocal frequency doubling of electromagnetic waves through double resonance and Bragg reflection in photonic crystals,” Cur. Appl. Phys. 12, 214 (2012).

2011

1. S. C. Yun, H. W. Kim, M. W. Kim, H. G. Park, J. S. Kim, C. S. Jun, F. Rotermund, D. I. Yeom, "Passively mode-locked fiber laser with an adjustable cavity length for the pump-probe technique," Sae Mulli 61, 1121 (2011). (in Korean) 

2. B. P. Nguyen, K. Kim, F. Rotermund, H. Lim, “Enhanced localization of waves in one-dimensional random media due to nonlinearity: Fixed input case,” Physica B 46, 4535 (2011).

3. E. W. Barrera, M. C. Pujol, F. Díaz, S. B. Choi, F. Rotermund, C. Cascales, “Hydrothermal trivalent lanthanide doped Lu2O3 nanorods: Evaluation of the influence of the surface in optical emission properties,” Opt. Mater. 34, 399 (2011).

4. W. B, Cho, J. W. Kim, H. W. Lee, S. Bae, B. H. Hong, S. Y. Choi, I. H. Baek, K. Kim, D.-I. Yeom, F. Rotermund, “High-quality, large-area monolayer graphene for bulk laser mode-locking near 1.25 μm,” Opt. Lett. 36, 4089 (2011). (featured in News & Analysis of MRS Bulletin, December issue, MRS Bulletin 36, 952 (2011)).

5. C. S. Jun, J. H. Im, S. H. Yoo, S. Y. Choi, F. Rotermund, D.-I. Yeom, B. Y. Kim, “Low noise GHz passive harmonic mode-locking of soliton fiber laser using evanescent wave interaction with carbon nanotubes,” Opt. Express 19, 19775 (2011).

6. S. Kim, F. Rotermund, K. Kim, „Invariant Imbedding approach for electromagnetic scattering from cylindrical bodies with metamaterial coatings,” J. Kor. Phys. Soc. 59, 39 (2011).

7. I. H. Baek, S. Y. Choi, H. W. Lee, W. B, Cho, V. Petrov, A. Agnesi, V. Pasiskevicius, D.-I. Yeom, K. Kim, F. Rotermund, “Single-walled carbon nanotube saturable absorber assisted high-power mode-locking of a Ti:sapphire laser,” Opt. Express 19, 7833 (2011).

8. W. B, Cho, S. Y. Choi, J. W. Kim, D.-I. Yeom, K. Kim, H. Lim, F. Rotermund, “Solid-state laser mode-locking near 1.25 μm employing a carbon nanotube saturable absorber mirror,” J. Opt. Soc. Kor. 15, 56 (2011).

9. V. Petrov, V. L. Panyutin, A. Tyazhov, G. Marchev, A. I. Zagumennyi, F. Rotermund, F. Noack, K. Miyata, S. D. Iskhakova, A. F. Zerrouk, “A qualitative analysis of the optical reflection properties of self-assembled opal films.

10. K. S. Cho, P. Mandal, K. Kim, I. H. Baek, S. Lee, H. Lim, D. J. Cho, S. Kim, J. Lee, F. Rotermund, “Improved efficiency in GaAs solar cells by dielectric 1D and 2D nanopatterns fabricated by laser interference lithography,” Opt. Commun. 284, 2608 (2011). 

11. Q. M. Ngo, S. Kim, H. Lim, P. T. Nga, P. T. Linh, N. X. Nghia, F. Rotermund, K. Kim, A. Avoine, A. Maitre, “A qualitative analysis of the optical reflection properties of self-assembled opal films,” Cur. Appl. Phys. 11, 643 (2011).

12. S. B. Choi, J. Kyoung, H. S. Kim, H. R. Park, D. J. Park, B.-J. Kim, Y. H. Ahn, F. Rotermund, H.-T. Kim, K. J. Ahn, D. S. Kim, “Nanopattern enabled terahertz all-optical switching on Vanadium dioxide thin film,” Appl. Phys. Lett. 98, 071105 (2011).

13. X. Mateos, M. Segura, W. B. Cho, A. Schmidt, F. Rotermund, M. C. Pujol, J. J. Carvajal, M. Aguiló, F. Díaz, V. Panyutin, U. Griebner, V. Petrov, “Pulsed 2-micron lasers based on Tm3+-doped monoclinic double tungstate crystals,” Proc. SPIE 8039, 803902-1 (2011). (invited paper)

14. E. W. Barrera, M. C. Pujol, F. Díaz, S. B. Choi, F. Rotermund, K. H. Park, M. S. Jeong, C. Cascales, “Emission properties in hydrothermal Yb3+, Er3+, Tm3+-codoped Lu2O3 nanorods: upconversion, cathodoluminescence, and assessment of waveguide behavior,” Nanotech. 22, 075205 (2011).

15. P.-J. Kim, J.-H. Jeong, M. Jazbinsek, S. J. Kwon, H. Yun, J. T. Kim, Y. S. Lee, I.-H. Baek, F. Rotermund, P. Guenter, O-P. Kwon, “Acentric nonlinear optical N-Benzyl stilbazolium crystals with high environmental stability and enhanced molecular nonlinearity in solid state,” CrystEngComm. 13, 444 (2011).