Pr：YLF
219757274
Blue diode pumped single longitudinal mode Pr:YLF lasers in orange spectral region
Abstract We report on blue diode pumped single frequency Pr:YLF lasers in orange spectral region, for the first time to the best of our knowledge. For a single frequency s polarized 607 nm laser, a maximum output power up to 175 mW is achieved with a slope efficiency of about 16.6% Linewidth of the 607 nm single frequency laser is measured to be about 6 MHz. Single frequency operation has also been obtained at p polarized 604 nm laser with a maximum output power up to 91 mW and a slope efficiency of about 8.9% The corresponding linewidth of the 604 nm laser is about 22 MHz. The two single frequency orange lasers exhibit wavelength tuning ranges of about 0.15 nm and 0.35 nm, respectively. This work has proposed the simplest way for single frequency laser generation in orange spectral region, which could be obtained by complicated and low efficiency sum frequency mixing of Nd3+ lasers. This work paves a practical way for various orange related applications.
Yunshan Zhang Lunbin Zhou Teng Zhang Yaqi Cai Bin Xu Xiaodong Xu Jiale Xu
224842731
Direct generation of visible vortex Hermite Gaussian modes in a diode pumped Pr:YLF laser
Abstract We report the first experimental realization of visible vortex Hermite Gaussian beams in a diode pumped Pr:YLF laser. The maximum output power of a first order vortex laser reaches 320 mW. Vortex and vortex Hermite Gaussian lasers are created in this experiment only by regulating the output mirror. Moreover, the phases of vortex Hermite Gaussian modes are verified by interference fringes.
Shengwei Cui Nan Li Bin Xu Huiying Xu Zhiping Cai Jixiong Pu Sabino Chavez-Cerda
213313362
604 nm high order vortex beams directly generated from a Pr:YLF laser with a cavity loss induced gain switching mechanism
Abstract In this work, we demonstrated, for the first time to the best of our knowledge, high order vortex beams at 604 nm that were directly emitted from a Pr:YLF crystal laser. By combining a blue diode pumped v type cavity for controllable Gouy phase introduction and off axis crystal rotation for high order HG modes generation, topological charged 604 nm vortex lasers were attained up to the third order. Furthermore, the vortex beams were found to be lasing at 604 nm that was often deemed less prone to lase compared with 607 nm in the same energy manifold. By a detailed spectroscopic study and rate equation analysis, we proposed and confirmed that the 604 nm transition of Pr:YLF crystal could be favorable in the vortex beam generation by a cavity loss induced gain switching process, in which the net gain at 604 nm could surpass that of 607 nm as the cavity loss was amassed beyond a threshold value.
Saiyu Luo Zhiping Cai Chuanxiang Sheng Lianhe Li Qian Chen
218967260
Single longitudinal mode Q switched operation of Pr:YLF laser with pre lase and Fabry Perot etalon technology
Abstract This letter presents a visible light direct oscillation Q switched single longitudinal mode Pr:YLF laser output at 639.5 nm by using the Q switching pre lase technology combined with the Fabry Perot etalon. The experimental results show that the single longitudinal mode oscillation can be generated in a low energy injection state. The proposed laser overcomes the problem associated with the Q switched Pr:YLF laser, which cannot produce high efficiency single longitudinal mode owing to the high loss of inserted elements. With the proposed laser, a Q switched single longitudinal mode pulsed laser output has been achieved with 3.94 mJ energy and 81.1 ns pulse duration at a repetition of 10 kHz. The spectral linewidth of single longitudinal mode pulse laser was approximately 33 MHz.
Long Jin Weicheng Dai Yong-ji Yu Yuan Dong Guang-yong Jin
219407499
640 nm Pr:YLF regenerative amplifier seeded by gain switched laser diode pulses.
We demonstrated the regenerative amplification of picosecond laser pulses generated by a gain switched laser diode at 640 nm with a Pr:YLF crystal that was continuously pumped by a multimode blue laser diode. A 0.7 pJ seed pulse energy sufficiently suppressed the self oscillation in the amplifier. The amplified pulse energy reached 33 uJ at a repetition rate of 10 kHz. The spatial beam quality was nearly TEM00. We also demonstrated second and third harmonic generation and obtained 320 and 213 nm pulse energies of 18 and 0.83 uJ at 10 kHz.
Applied optics
Yusaku Hara Shogo Fujita Yuta Shioya F Kannari
201270919
High Order Vortex Generation From CW and Passively Q Switched Pr:YLF Visible Lasers
We report on the high order transverse mode generation in a diode pumped Pr:YLF visible laser operating at 639 nm. Using a two mirror linear cavity and operating the laser in continuous wave regime, tunable Hermite Gaussian modes HG0,m have been directly generated with m varying from 0 up to 120 by off axis pumping and misaligning the laser resonator. In the same way, but using a V shaped cavity and adding a Co:ASL saturable absorber, high order HG0,m modes were also generated in Q switched regime with m varying up to 12. The achieved passively Q switched laser has a pulse width of about 149 ns at a repetition rate of 91 kHz, which leads to a pulse energy of about 2.5 \mu \text{J} and a pulse peak power of 16.9 W. In both cases, intracavity HG0,m modes were converted into the corresponding Laguerre Gaussian modes LG0,m via a pair of cylindrical lenses placed outside the cavity and the helical nature of the wavefronts were checked by using a specially designed Fizeau interferometer. Such tunable and directly generated high order laser transverse modes obtained in continuous wave as well as in Q switched regimes are well suited for various modern applications, such as optical manipulation and 3D material processing.
IEEE Photonics Technology Letters
Nan Li Bin Xu Shengwei Cui Xiaodong Qiu Zhengqian Luo Huiying Xu Zhiping Cai Lixiang Chen Richard Moncorge
128329941
Direct oscillation at 640 nm in single longitudinal mode with a diode pumped Pr:YLF solid state laser
Abstract A diode pumped solid state laser directly emitting continuous wave (cw) single longitudinal mode (SLM) output at 640 nm with a c cut praseodymium doped yttrium lithium fluoride (Pr:YLF) crystal was demonstrated for the first time, to the best of our knowledge. Combining two quarter wave plates (QWPs) and one Brewster plate to form a twisted mode cavity, this SLM solid state laser achieved a maximum cw output power of 403 mW with a threshold of 600 mW and a slope efficiency of 26.8% The emission spectrum had a linewidth of 150 MHz. The single mode beam quality (M2) was 1.10 and 1.07 along the x and y direction, respectively.
Optics Laser Technology
Saiyu Luo Zhiping Cai Huiying Xu Zhe Shen Hao Chen Li Li Yun Cao
208039950
Direct generation of orthogonally polarized dual wavelength continuous wave and passively Q switched vortex beam in diode pumped Pr:YLF lasers.
We report on direct generation of an orthogonally polarized dual wavelength vortex laser, for the first time to our knowledge, by means of a diode pumped V shaped Pr:YLF laser platform. A method of misaligning the folded mirror is proposed to realize the simultaneous orthogonally polarized dual wavelength laser, while a method of orthogonally rotating the laser gain medium is proposed to generate an intracavity vortex beam (LG01 mode) With the two methods, in continuous wave (CW) mode, we have achieved simultaneous lasing of an orthogonally polarized dual wavelength vortex laser at 604 and 607 nm with maximum output power of 237.7 mW. Moreover, based on this operation, a simultaneous orthogonally polarized dual wavelength passively Q switched vortex laser is also realized by inserting a Co:ASL crystal into the laser resonator as a saturable absorber. This work provides the simplest way for direct generation of an orthogonally polarized dual wavelength vortex laser for potential applications.
Optics letters
Qingyu Tian Bin Xu Nan Li Zhengqian Luo Huiying Xu Zhiping Cai
195756782
Diode pumped 640 nm Pr:YLF regenerative laser pulse amplifier.
We demonstrated regenerative laser pulse amplification at 640 nm for the first time, to the best of our knowledge, with a mode locked Pr3+ doped LiYF4 (Pr3+:YLF) oscillator as a picosecond seed pulse. A regenerative amplifier with a Pr3+:YLF crystal was continuously pumped by a multimode InGaN diode laser. At an absorbed pump power of 3.1 W, we obtained amplified pulse energy of 13 mJ at 10 kHz with an excellent spatial beam quality of M2~1.1, demonstrated second harmonic generation, and obtained a 320 nm pulse energy of 5.9 mJ.
Optics letters
Naoto Sugiyama Shogo Fujita Yusaku Hara Hiroki Tanaka F Kannari
227074751
Performance prediction of single longitudinal mode operation in Pr:YLF laser under pre lase technology
We develop a theoretical model of multimode rate equation that accurately describes mode evolution mechanism of prelase Q switched Pr3+:YLF single longitudinal mode (SLM).The theoretical simulation process explained each part of the operation and experimental phenomenon in the pre lase process effectively.We identify that there is an optimal parameter for the two step signal of acoustic optic modulator which determines the stability of SLM output.Our theoretical model can be applied to most solid state lasers, and offer theoretical references for the design and construction of experimental facilities, which is significant for future research.Up to now, there is still not a complete theory to accurate description of prelase Q switching technology. Moreover, there have been no reported about directly emitting Q switched SLM laser in the visible region.
Applied Optics and Photonics China
Long Jin Weicheng Dai Yuan Dong Yong-ji Yu Chi Feng Jingdong Sun