Research Core for Extreme Quantum World, Okayama University, Okayama, Japan.
Opt Lett. 2013 Aug 1;38(15):2825-8. doi: 10.1364/OL.38.002825.
Difference-frequency generation of 4.8 μm mid-infrared light was performed using a waveguide periodically poled LiNbO₃ (PPLN) crystal. 871 and 1064 nm external-cavity diode lasers followed by tapered amplifiers were used as pump sources. A conversion efficiency of ~2%/W with the output power of 2 mW was achieved even under considerable absorption of the crystal at this wavelength. Lamb-dip spectroscopy of carbonyl sulfide was demonstrated showing the satisfactory performance of this device for saturation spectroscopy. The observed dip width shows that the laser linewidth is ~2 MHz, which corresponds to those of the pump lasers.
采用波导周期性极化铌酸锂（PPLN）晶体实现了 4.8 μm 中红外光的差频产生。871nm 和 1064nm 的外腔半导体激光器经锥形放大器后作为泵浦源。在该波长下，晶体有相当大的吸收，仍实现了约 2%/W 的转换效率和 2mW 的输出功率。对羰基硫的兰姆凹陷光谱进行了演示，表明该器件在饱和光谱学方面具有令人满意的性能。观察到的凹陷宽度表明激光线宽约为 2MHz，与泵浦激光器的线宽相对应。
