中国物理B ›› 2003, Vol. 12 ›› Issue (11): 1246-1250.doi: 10.1088/1009-1963/12/11/311

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The mechanism research of the Cr4+Nd3+:YAG laser

陈晓波1, 王凌1, 吕兰斌2, 张治国2, 杨国桢2, Zhu Jane G.3, 杜为民3   

  1. (1)Applied Optics Beijing Area Major Laboratory, Beijing Normal University, Beijing 100875, China; (2)Laboratory of Optical Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China; (3)Physics School, Peking University, Beijing 100871, China
  • 收稿日期:2003-03-14 修回日期:2003-06-02 出版日期:2003-11-16 发布日期:2005-03-16
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos 19874033 and 10174008).

The mechanism research of the Cr4+Nd3+:YAG laser

Chen Xiao-Bo (陈晓波)a, Wang Ling (王凌)a, Lü Lan-Bin (吕兰斌)b, Zhang Zhi-Guo (张治国)b, Zhu Jane G.c, Du Wei-Min (杜为民)c, Yang Guo-Zhen (杨国桢)b   

  1. a Applied Optics Beijing Area Major Laboratory, Beijing Normal University, Beijing 100875, China; b Laboratory of Optical Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China; c Physics School, Peking University, Beijing 100871, China
  • Received:2003-03-14 Revised:2003-06-02 Online:2003-11-16 Published:2005-03-16
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos 19874033 and 10174008).

摘要: The 946nm diode-pump microchip self-Q-switched laser of a chromium and neodymium codoped yttrium aluminum garnet crystal material (Cr^{4+}Nd^{3+}:YAG) is studied, especially about its physical mechanism of operation. The {}^4F_{3/2}→{}^4I_{9/2} transition of Nd^{3+} ion is beneficial to achieving laser oscillation in a quasi-three-level system based on coating the cavity mirrors of the microchip with films that suppress the 1064nm operation and enhance the 946nm laser. The Cr^{4+} ion is a saturable absorber. The initial loss N_{t1} is high, which acts as the threshold for laser oscillation. The stable loss N_{t2} is low because the Cr^{4+} ion is acceleratively bleached by the fast enhancement of the oscillating laser. The high N_{t1}, small N_{t2} and fast progresses permit the oscillating laser of the Cr^{4+}Nd^{3+}:YAG to have a good self-Q-switched property whose full width at half maximum is about 4.2ns. Its highest laser power is about 5.7mW. Its peak power is about 150W. Its good fundamental transverse TEM_{00} mode results from the absorption bleaching established by both the pump and oscillating lasers, which suppress other transverse mode and allow the oscillation only in the fundamental transverse TEM_{00} mode.

Abstract: The 946nm diode-pump microchip self-Q-switched laser of a chromium and neodymium codoped yttrium aluminum garnet crystal material (Cr$^{4+}$Nd$^{3+}$:YAG) is studied, especially about its physical mechanism of operation. The ${}^4$F$_{3/2}→{}^4$I$_{9/2}$ transition of Nd$^{3+}$ ion is beneficial to achieving laser oscillation in a quasi-three-level system based on coating the cavity mirrors of the microchip with films that suppress the 1064nm operation and enhance the 946nm laser. The Cr$^{4+}$ ion is a saturable absorber. The initial loss $N_{\rm t1}$ is high, which acts as the threshold for laser oscillation. The stable loss $N_{\rm t2}$ is low because the Cr$^{4+}$ ion is acceleratively bleached by the fast enhancement of the oscillating laser. The high N$_{\rm t1}$, small $N_{\rm t2}$ and fast progresses permit the oscillating laser of the Cr$^{4+}$Nd$^{3+}$:YAG to have a good self-Q-switched property whose full width at half maximum is about 4.2ns. Its highest laser power is about 5.7mW. Its peak power is about 150W. Its good fundamental transverse TEM$_{00}$ mode results from the absorption bleaching established by both the pump and oscillating lasers, which suppress other transverse mode and allow the oscillation only in the fundamental transverse TEM$_{00}$ mode.

Key words: self-Q-switched, 946nm laser, Cr$^{4+}$Nd$^{3+}$:YAG

中图分类号:  (Microcavity and microdisk lasers)

  • 42.55.Sa
42.60.Gd (Q-switching) 42.70.Mp (Nonlinear optical crystals) 42.55.Rz (Doped-insulator lasers and other solid state lasers) 42.60.By (Design of specific laser systems) 42.70.Hj (Laser materials) 78.30.-j (Infrared and Raman spectra) 42.50.Gy (Effects of atomic coherence on propagation, absorption, and Amplification of light; electromagnetically induced transparency and Absorption)