Dr. Yongji Yu Profile

Dr. Yongji Yu

at Changchun Univ of Science and Technology

SPIE Involvement:

Author

Publications (8)

Proceedings Article | 13 February 2025 Open Access

Multiparameter dependence of laser-induced CFRP surface processing mechanism

Siqi Liu, Jie Luo, Peiyan Cong, Yao Ma, Yongji Yu

Proceedings Volume 13543, 135430T (2025) https://doi.org/10.1117/12.3059283

KEYWORDS: Laser irradiation, Picosecond phenomena, Pulsed laser operation, Composites, Laser processing, Carbon fibers, Laser energy, Ultraviolet radiation, Surface roughness, Infrared radiation

Read Abstract +

DOWNLOAD PAPER

Proceedings Article | 5 November 2020 Paper

Performance prediction of single-longitudinal-mode operation in Pr:YLF laser under pre-lase technology

Long Jin, Weicheng Dai, Yuan Dong, Yongji Yu, Chi Feng, Jingdong Sun

Proceedings Volume 11562, 115620I (2020) https://doi.org/10.1117/12.2576221

KEYWORDS: Spatial light modulators, Q switching, Q switched lasers, Signal processing, Signal attenuation, Laser applications, Mathematical modeling, Solid state lasers, Pulsed laser operation

Read Abstract +

Proceedings Article | 18 December 2019 Paper

Active multi-wavelength Šolc-type filter based on MgO:APLN

Hang Liu, Yuheng Wang, Lujie Li, Yongji Yu, Guangyong Jin

Proceedings Volume 11334, 1133407 (2019) https://doi.org/10.1117/12.2539577

KEYWORDS: Crystals, Transmittance, Polarization, Filtering (signal processing), Optical filters, Nonlinear crystals, Tunable filters

Read Abstract +

Proceedings Article | 18 December 2014 Paper

Widely tunable mid-infrared optical parametric oscillator based on a multiple periods MgO:PPLN

Yong-ji Yu, Rui-zhi Zhai, Jing Zhao, Xin-yu Chen, Chao Wang, Chun-ting Wu, Guang-yong Jin

Proceedings Volume 9295, 92950W (2014) https://doi.org/10.1117/12.2073102

KEYWORDS: Optical parametric oscillators, Crystals, Mid-IR, Laser crystals, Temperature metrology, Semiconductor lasers, Acousto-optics, Neodymium lasers, Pulsed laser operation, Tunable lasers

Read Abstract +

SPIE Journal Paper | 2 December 2013

High-repetition-rate tunable mid-infrared optical parametric oscillator based on MgO: periodically poled lithium niobate

Yongji Yu, Xinyu Chen, Jing Zhao, Chao Wang, Chunting Wu, Guangyong Jin

OE, Vol. 53, Issue 06, 061604, (December 2013) https://doi.org/10.1117/12.10.1117/1.OE.53.6.061604

KEYWORDS: Optical parametric oscillators, Crystals, Mid-IR, Neodymium, Lithium niobate, Q switched lasers, Q switching, Mirrors, Electro optics, Reflectivity

Read Abstract +

Proceedings Article | 17 September 2013 Paper

86 W continuous-wave diode side-pumped 1341.4nm Nd:YAP laser

Yong-ji Yu, Jing Zhao, Xin-yu Chen, Chao Wang, Chun-ting Wu, Guang-yong Jin

Proceedings Volume 8904, 89041O (2013) https://doi.org/10.1117/12.2035107

KEYWORDS: Crystals, Semiconductor lasers, Continuous wave operation, Laser crystals, Diodes, High power lasers, Mirrors, Laser applications, Neodymium lasers, Resonators

Read Abstract +

Proceedings Article | 17 September 2013 Paper

LD dual-end-pumped CW Tm:YLF laser

Xin-yu Chen, Yu Zhang, Yong-ji Yu, Chao Wang, Guang-yong Jin

Proceedings Volume 8904, 890417 (2013) https://doi.org/10.1117/12.2034533

KEYWORDS: Continuous wave operation, Resonators, Crystals, Mirrors, Thulium, Laser crystals, Ions, Laser damage threshold, Upconversion, Thermal effects

Read Abstract +

We report on a LD dual-end-pumped 792nm continuous wave operation Tm:YLF laser. Firstly, the rate equation of LD end-pumped CW operation Tm:YLF laser were established, in which the energy transfer upconversion and without energy transfer upconversion under continuous-wave considerate were considered, as well the pump threshold and the slope efficiency of the laser system were analyzed. Simultaneously, the cavity stability condition and the pattern matching of the plano- concave resonator were analyzed according to ABCD Matrix theory. Comparing respectively the laser threshold and the slope efficiency and optical-optical conversion efficiency under circumstances which the output mirror transmittance of 15% and 23%. In addition, the M2 of the output laser were contrasted and analyzed in adjusting the resonator cavity length by using different radius of curvature of the output mirror in 150mm, 200mm and 300mm all in the above case. As the process of thermal lens focal length changing greater than 90mm, it exhibited that the two fundamental modes in the cavity resonator matched well in numerical simulation when the radius of curvature of the output mirror was 300mm, as well the two fundamental modes matched well when it more than 100mm in a certain pump power. We designed a single LD dual-end-pumped continuous wave operation Tm:YLF laser. Using Tm:YLF (3 at.%) crystal for gain medium, which the size was 3×3×14mm³. In experiments, the Tm:YLF laser crystal keeps 291K and the temperature control method is water cooling. The length of the resonator was 135mm when L shape plano-concave resonator was applied, and the radius of curvature output mirror was 300mm, as well as the temperature of the Tm:YLF laser crystal was 291K. The output laser we observed by this system and the central laser wavelength was 1944nm. The threshold power was 8.11W and the highest output power reaches to 4.01W when the totally input pump power was 17W, and the optical conversion efficiency was 23.6%. The far-field divergence angle was 3.8mrad after calculation. Respectively. The experimental results are coinciding with the theory.

Proceedings Article | 29 August 2009 Paper

High-power Nd:YAP blue laser by intracavity summing frequency

Yong-ji Yu, Guang-yong Jin, Chao Wang, Da-wei Hao, Jia-xi Guo, Zhu Liang

Proceedings Volume 7382, 73820F (2009) https://doi.org/10.1117/12.835226

KEYWORDS: Crystals, Laser crystals, Semiconductor lasers, High power lasers, Harmonic generation, Pulsed laser operation, Nonlinear crystals, Thermal effects, Second-harmonic generation, Phase matching

Read Abstract +

Showing 5 of 8 publications

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years