Article
Physics, Applied
Huilong Liu, Zhexian Zhao, Jing Xia, Yanfei Lu
Summary: A tunable Pr3+:LiYF4 laser was demonstrated to operate at nine different laser wavelengths using a single birefringent filter, with new wavelengths obtained and a total tuning range exceeding 190nm. Additionally, a continuous-wave simultaneous dual-wavelength laser was achieved by adjusting the rotation angle of the filter plate, showing maximum output powers at 698nm and 720nm.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Optics
Zhuang Li, Shaoqiang Zheng, Zhiping Cai, Run Fang, Bo Xiao, Huiying Xu
Summary: We present a continuously broadband tunable Pr3+:LiYF4 (Pr:YLF) laser in the near-infrared spectra range pumped by InGaN laser diodes (LDs). The upper energy level of the laser utilizes composite energy levels (3P0,1,1I6). The laser achieves a continuous tuning range of 855 nm to 931 nm (width of 77 nm) for pi-polarization and 850 nm to 912 nm (width of 63 nm) for sigma-polarization, with absorbed pumped power of approximately 9 W at 444 nm. The laser also demonstrates the highest tuning power and widest continuous tuning range to date, with the ability to generate thirteen new wavelengths in the Pr:YLF crystal.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Optics
Zhengda Sun, Feifei Wang, Haiping Xia, Hongkun Nie, Kejian Yang, Ruihua Wang, Jingliang He, Baitao Zhang
Summary: This study investigated the absorption and fluorescence spectra of Er3+ and Pr3+ co-doped LiYF4 crystals, showing that Pr3+ co-doping effectively enhances the mid-infrared transition of Er3+. Using Judd-Ofelt theory, the stimulated emission cross section was calculated and a diode-end-pumped Er,Pr:YLF laser operating at 2659 nm was successfully realized for the first time. This laser showed promising potential for 2.7 μm laser generation.
CHINESE OPTICS LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Zhuang Li, Rongfei Huang, Wei Yuan, Shaoqiang Zheng, Wenlu Liao, Huiying Xu, Zhiping Cai
Summary: This study reports the first realization of an 868 nm Pr:YLF laser pumped by an InGaN blue laser diode. The laser achieved a maximum power of 641 mW with stable output and good beam quality. The experimental results were in agreement with theoretical simulations.
Review
Engineering, Electrical & Electronic
Hiroki Tanaka, Sascha Kalusniak, Moritz Badtke, Maxim Demesh, Nikolai Kuleshov, Fumihiko Kannari, Christian Krankel
Summary: This article reviews the current state of continuous wave and pulsed visible solid-state lasers and amplifiers based on Pr3+ and Tb3+ as the active ion. It discusses the spectroscopic properties of these ions, suitable host materials, and the prospects for power scaling. Visible solid-state lasers have wide-ranging applications, but they are still in an early stage of development.
PROGRESS IN QUANTUM ELECTRONICS
(2022)
Article
Optics
Jiaxin He, Feifei Wei, Huilong Liu, Jing Xia, Rui Yang, Yanfei Lu
Summary: In this study, the first tunable continuous-wave simultaneous dual-wavelength laser operation of a Pr3+:LiYF4 crystal in the 900 nm spectral range using a single birefringent filter (BF) was achieved by adjusting the rotation angle of the BF. CW simultaneous dual-wavelength lasers operating at 869 and 915 nm, 894 and 915 nm, 915 and 923 nm were obtained respectively.
LASER PHYSICS LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Yuchen Xue, Zhengdong Dai, Weihang Cao, Zhongyu Wang, Bo Xiao, Huiying Xu, Zhiping Cai
Summary: This paper presents the first demonstration of three new wavelengths in the sigma-polarized direction using a continuous-wave Pr3+:LiYF4 laser. The transitions mechanism is proposed based on dual upper energy levels and Stark sub-levels. The lasers achieve high output power at room temperature.
IEEE JOURNAL OF QUANTUM ELECTRONICS
(2023)
Article
Optics
Teng Zhang, Lunbin Zhou, Jingyu Zou, Yikun Bu, Bin Xu, Xiaodong Xu, Jun Xu
Summary: In this study, compact blue-diode-pumped Pr,Mg:SrAl12O19 (SRA) lasers were demonstrated in continuous-wave and passively Q-switched regimes. The lasers showed promising performance in terms of output powers and efficiencies, highlighting the potential of Pr,Mg:SRA as a compact and efficient laser source in the visible spectral range.
OPTICS AND LASER TECHNOLOGY
(2021)
Article
Optics
Yifeng Zhu, Xinhua Fu, Lintao Yu
Summary: We report the simultaneous continuous-wave red, green, and blue laser operations in praseodymium-doped crystalline materials for the first time. The maximum output power, including three wavelengths (red: 607 nm, green: 523 nm, blue: 479 nm), was 665 mW at an absorbed pump power of 4.7 W (or 10 W of incident pump power), with an optical conversion efficiency of 14.1%.
Article
Optics
Wanxin Zheng, Jingyu Zou, Dong Wang, Bin Xu, Andrey Lyapin, Polina Ryabochkina, Xudong Cui, Vadim Semashko, Stella Korableva
Summary: This work reports the recent progress of diode-pumped continuous-wave Pr:LiY0.3Lu0.7F4 lasers in the visible spectral region. By partially substituting Y3+ ions, orange and deep red lasers have been achieved in the Pr:LiY0.3Lu0.7F4 mixed crystal, which represents the best laser performance for Pr3+ mixed crystals.
OPTICS AND LASER TECHNOLOGY
(2022)
Article
Optics
Martin Fibrich, Jan Sulc, Richard Svejkar, Helena Jelinkova
Summary: This study has successfully demonstrated the first continuous-wave quasi three-level laser emitting in the cyan-blue spectral range in praseodymium-doped oxide materials, achieving a high output power and efficiency.
APPLIED PHYSICS B-LASERS AND OPTICS
(2021)
Article
Chemistry, Multidisciplinary
Xiaolong Liu, Kang Wang, Ang Ren, Tongjin Zhang, Shizhe Ren, Jiannian Yao, Haiyun Dong, Yong Sheng Zhao
Summary: A metal-linking approach is proposed to enhance the Raman gain of organic molecules, allowing for continuous-wave (c.w.) organic lasers. Broadband tunable Raman lasing is achieved by adjusting excitation wavelengths.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Xiaolong Liu, Kang Wang, Ang Ren, Tongjin Zhang, Shizhe Ren, Jiannian Yao, Haiyun Dong, Yong Sheng Zhao
Summary: Stimulated Raman scattering offers an alternative strategy for continuous-wave (c.w.) organic lasers, but suffers from inadequate Raman gain in organic material systems. In this study, a metal-linking approach is proposed to enhance the Raman gain of organic molecules. Self-assembled microcrystals of metal-linked organic dimers exhibit large Raman gain, enabling c.w. Raman lasing. Broadband tunable Raman lasing is achieved in the organic dimer microcrystals by adjusting excitation wavelengths. The work contributes to the understanding of Raman gain in organic molecules and provides a pathway for designing c.w. organic lasers.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Engineering, Electrical & Electronic
Roopa Prakash, Vishal Choudhury, S. Arun, V. R. Supradeepa
Summary: The addition of transmission fiber before the nonlinear broadening stage overcomes poor spectral flatness and sensitivity issues in low-power continuous-wave pumped supercontinuum sources. The proposed two-stage spectral broadening technique successfully demonstrates a continuous-wave pump wavelength agile all-fiber supercontinuum module with spectra spanning from 1300 nm to 2000 nm.
IEEE PHOTONICS TECHNOLOGY LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Kaichuan Wen, Yu Cao, Lianghui Gu, Saixue Wang, Dongmin Qian, Jingmin Wang, Zhiyuan Kuang, Mengyi Luo, Gang Wang, Shuzhen Guan, Mengmeng Li, Heng Yang, Guichuan Xing, Nana Wang, Lin Zhu, Qiming Peng, Wei Huang, Jianpu Wang
Summary: Continuous-wave lasing is achieved in an efficient perovskite LED with an integrated distributed feedback resonator, showing a low threshold at low temperature. The LED functions well even at high current density, suggesting the potential realization of electrically pumped perovskite laser diodes.
ADVANCED MATERIALS
(2023)
Article
Optics
Moritz Badtke, Hiroki Tanaka, Lenn J. Ollenburg, Sascha Kalusniak, Christian Kraenkel
Summary: This study demonstrates the generation of short pulses from a passively Q-switched Pr3+:LiYF4 laser operating at 640 nm. By optimizing the cavity length and using the saturable absorber Co:MgAl2O4, they achieved the shortest pulse durations compared to other Q-switched Pr3+ lasers. The laser produced pulses with varying energy and duration at different repetition rates.
APPLIED PHYSICS B-LASERS AND OPTICS
(2021)
Article
Materials Science, Multidisciplinary
Kore Hasse, Detlef Kip, Christian Kraenkel
Summary: It is shown that utilizing MHz repetition rates for fs-laser written structures in YAG crystals and a diluted mixture of H3PO4 and H2SO4 can significantly improve inscription velocity and selective etching efficiency. This approach achieves record high writing velocities and increased selectivity, providing a more efficient and precise microchannel fabrication process.
OPTICAL MATERIALS EXPRESS
(2021)
Article
Materials Science, Multidisciplinary
Christian E. Rueter, Kore Hasse, Feng Chen, Detlef Kip
Summary: A neodymium doped lithium-niobate-on-insulator (LNOI) was successfully fabricated using diffusion doping, allowing for different doped regions on a single substrate. Optical properties of Nd:LNOI were studied for the first time, showing promise for future applications in highly integrated photonics.
OPTICAL MATERIALS EXPRESS
(2021)
Article
Optics
Sascha Kalusniak, Elena Castellano-Hernandez, Hasan Yalcinoglu, Hiroki Tanaka, Christian Kraenkel
Summary: This paper reviews the latest developments in Tb3+-based solid-state lasers, summarizes the spectroscopic properties, and provides valuable guidelines and recommendations for improving performance through the choice of host materials.
APPLIED PHYSICS B-LASERS AND OPTICS
(2022)
Article
Optics
R. Moncorge, Y. Guyot, C. Kraenkel, K. Lebbou, A. Yoshikawa
Summary: The study focused on the absorption and emission properties of Tm3+-doped sesquioxides Y2O3, Lu2O3, and Sc2O3 at different wavelengths. It was discovered that only 75% of the Tm3+ ions were involved in the absorption and emission spectra, leading to calculations of cross sections for important excited-state transitions.
JOURNAL OF LUMINESCENCE
(2022)
Article
Optics
Ji Eun Bae, Thomas Calmano, Christian Kraenkel, Fabian Rotermund
Summary: This study demonstrates the dynamic single- and dual-channel graphene Q-switching of a Yb:YAG waveguide by controlling the power-splitting ratio, enabling the selective excitation of individual channels and controlled splitting ratios of output powers. The beam-splitter-type waveguide laser developed in this study has potential advantages in various applications such as optical communication, metrology, and sensing.
LASER & PHOTONICS REVIEWS
(2022)
Article
Optics
Stefan Pueschel, Felix Mauerhoff, Christian Kraenkel, Hiroki Tanaka
Summary: This article reports the first example, to the best of our knowledge, of solid-state laser cooling in ytterbium-doped CaF2 and SrF2 crystals by anti-Stokes fluorescence. The crystals were grown in a fluorine-rich atmosphere using the Czochralski method to prevent the formation of divalent ytterbium ions. Experimental results and model calculations using temperature-dependent spectroscopic data suggest that these crystals have cooling efficiencies higher than 3% at room temperature and can be cooled to temperatures as low as 150 K when excited at around 1030 nm.
Review
Materials Science, Multidisciplinary
Christian Kraenkel, Anastasia Uvarova, Christo Guguschev, Sascha Kalusniak, Lena Huelshoff, Hiroki Tanaka, Detlef Klimm
Summary: Mixed sesquioxides are excellent host materials for rare-earth doped laser gain media, with reduced melting temperatures for easier fabrication and high optical quality. Due to their inhomogeneously broadened gain spectra caused by intrinsic disorder, mixed sesquioxides show great potential for the generation and amplification of ultrashort pulses.
OPTICAL MATERIALS EXPRESS
(2022)
Article
Physics, Applied
Moritz Badtke, Hiroki Tanaka, Sascha Kalusniak, Maxim Demesh, Nikolay Kuleshov, Christian Kraenkel
Summary: We present a study on the generation of few-ns pulses in the red and orange spectral range using a passively Q-switched Pr3+:YLF laser. By optimizing the resonator design and the initial transmission of the Co:MgAl2O4 saturable absorber, peak powers exceeding 1.1 kW were achieved at wavelengths of 640 nm and 607 nm, with pulse durations of 2.4 ns and 5.3 ns, respectively. These are the shortest pulse durations among any Q-switched Pr3+ lasers, making this system a potential candidate for efficient frequency doubling into the ultraviolet range.
APPLIED PHYSICS EXPRESS
(2022)
Review
Engineering, Electrical & Electronic
Hiroki Tanaka, Sascha Kalusniak, Moritz Badtke, Maxim Demesh, Nikolai Kuleshov, Fumihiko Kannari, Christian Krankel
Summary: This article reviews the current state of continuous wave and pulsed visible solid-state lasers and amplifiers based on Pr3+ and Tb3+ as the active ion. It discusses the spectroscopic properties of these ions, suitable host materials, and the prospects for power scaling. Visible solid-state lasers have wide-ranging applications, but they are still in an early stage of development.
PROGRESS IN QUANTUM ELECTRONICS
(2022)
Article
Optics
Anna Suzuki, Sascha Kalusniak, Hiroki Tanaka, Mario Bruetzam, Steffen Ganschow, Masaki Tokurakawa, Christian Kraenkel
Summary: This study reports on the growth, temperature-dependent spectroscopy, and laser experiments of Tm3+-doped YScO3 mixed sesquioxide crystals. Laser quality Tm3+:YScO3 crystals with different doping levels were successfully grown, and the structural disorder in the mixed crystals allows for broad and smooth spectral features even at cryogenic temperatures. Continuous wave laser operation in the 2.1μm range was achieved using these crystals, demonstrating their potential for efficient ultrafast pulse generation.
Article
Optics
Stefan Pueschel, Felix Mauerhoff, Christian Kraenkel, Hiroki Tanaka
Summary: This study compares the cooling performance of Yb3+-doped LiYF4 crystals with Yb:KYF crystals grown in our institute using laser cooling by anti-Stokes fluorescence. Yb:KYF exhibits better cooling performance at temperatures below 200K. Further improvement is possible for Yb:KYF crystals through optimizing the growth process and using purer raw materials.
Article
Optics
Moritz Badtke, Sascha Kalusniak, Hiroki Tanaka, Christian Kraenkel
Summary: We investigated the dependence of visible laser performance of Tb3+:LiLuF3 on the ultraviolet pumping wavelength and presented the first UV-laser-diode-pumped Tb3+-based laser. We found that thermal effects occur at moderate pump power for UV pump wavelengths with strong excited-state absorption, but disappear for wavelengths with weak absorption. Pumping with a UV laser diode emitting at 378.5 nm enables continuous wave laser operation in a 3mm short Tb3+(28 at.%):LLF crystal, achieving slope efficiencies of 36% at 542/544 nm and 17% at 587 nm, with a minimum laser threshold as low as 4 mW.
Proceedings Paper
Engineering, Electrical & Electronic
Anna Suzuki, Christian Kraenkel, Masaki Tokurakawa
Summary: This paper presents a combined gain media Kerr-lens mode-locked laser based on Tm-doped sesquioxide materials, achieving pulses as short as 60 fs with an average output power of 52 mW at 2.1um.
2021 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)
(2021)
Article
Optics
Ji Eun Bae, Sun Young Choi, Christian Krankel, Kore Hasse, Fabian Rotermund
Summary: A femtosecond-laser inscribed Yb:YAG surface channel waveguide (WG) laser with single-walled carbon nanotubes deposited on the top surface of the WG was passively Q-switched by evanescent field interaction. Q-switched operation of the compact Yb:YAG WG laser was achieved near 1031 nm with two different pumping schemes and an output coupling transmission of 91%. The Q-switched pulse characteristics depending on the absorbed pump power were investigated for both pumping geometries and analyzed in detail based on theoretical modeling. The best performances were 204.4 nJ/75 ns at a repetition rate of 1.87 MHz, and 201.1 nJ/81 ns at 1.75 MHz for single- and double-pass pumping, respectively.
CURRENT OPTICS AND PHOTONICS
(2021)
