高功率半导体激光器线阵列的波长锁定技术

Wavelength locked high power semiconductor laser linear array

高功率半导体激光器光谱随温度和工作电流的变化比较大,光谱线宽比较宽,这些缺点直接限制了其实际应用。因此,高功率半导体激光器波长稳定技术的研究是激光领域的一个重要研究方向。对波长稳定技术进行研究。实验用体布拉格光栅(VBG)作为反馈元件与高功率半导体激光器线阵列,构成可以对其波长进行锁定的外腔激光器。分析了外腔激光器的波长锁定效果与高功率半导体激光器工作电流、冷却温度、工作电流的占空比和"smile"现象等因素的关系。研究结果表明,高功率半导体激光器的工作电流、冷却温度、工作电流的占空比会影响其激射波长,当激射波长与VBG的布拉格波长差值小于3.0nm时,可以得到较好的波长锁定效果,而阵列本身的"smile"现象对其波长锁定的影响不大。

High-power laser diodes （HPLD） spectral linewidth is relatively broad （approximately 2-4 nm）. The wavelength shifts with temperature （by approximately 0.3 nm/K） and changes with current, and the beam quality is poor. Therefore, research on the thermal characteristics and wavelength stabilization of HPLD becomes one of the most important topics in the field. An external cavity laser was built using Volume Bragg Grating as feedback element and high power semiconductor linear array to lock it＇s stimulated wavelength. The relationship was analyzed among the wavelength locked and it＇s operational current, cooling temperature, duty cycle of the current and “smile”. The results indicate that the stimulated wavelength is influenced by the operational current, cooling temperature and the duty cycle. Besides the wavelength locked is better when the wavelength difference between the free running and the VBG Bragg wavelength is smaller than 3.0 nm, while wavelength locked wasn＇t influenced by it＇s “smile”.