Ashizawa Hiroaki, Ohara Shinobu, Yamaguchi Shigeru, Takahashi Masao, Endo Masamori, Nanri Kenzo, Fujioka Tomoo, Tittel Frank K
Department of Physics, School of Science, Tokai University, Hiratsuka, Kanagawa, Japan.
Jpn J Appl Phys. 2003 Mar;42(3):1263-7. doi: 10.1143/jjap.42.1263.
A high-power, narrow-linewidth Yb fiber laser with a fiber Bragg grating (FBG) pumped difference frequency generation (DFG) in a periodically poled lithium niobate (PPLN) crystal was investigated in detail. A mid-IR power of approximately 2.3 microW at 3.3 micrometers with a slope efficiency of 0.85 mW/W2 was achieved. A Doppler-broadened absorption spectrum of CH4 at 3038.497 cm-1 (3.2911 micrometers) was obtained with a 0.1-m long-gas cell at a pressure of 133 Pa. The linewidth of the DFG source was evaluated to be less than 96 MHz from the observed spectral linewidth. Real-time monitoring of CH4 (approximately 1.78 ppm) in ambient air in a multipass cell which has an optical path length of 10 m was also demonstrated.
详细研究了一种高功率、窄线宽的掺镱光纤激光器，该激光器通过光纤布拉格光栅（FBG）泵浦，在周期性极化铌酸锂（PPLN）晶体中产生差频（DFG）。在3.3微米波长处实现了约2.3微瓦的中红外功率，斜率效率为0.85毫瓦/瓦²。使用一个长度为0.1米、压力为133帕的气室，获得了甲烷在3038.497厘米⁻¹（3.2911微米）处的多普勒加宽吸收光谱。根据观察到的光谱线宽，评估DFG源的线宽小于96兆赫兹。还展示了在一个光程长度为10米的多程池中对环境空气中甲烷（约1.78 ppm）的实时监测。
