应用于吸收型甲烷传感器的1650nm DFB激光器的研制

Development of 1650nm DFB lasers applied in trace methane detection

光学吸收法是一种工程上有效可行的检测痕量甲烷气体的方法,具有广泛地应用于构建煤矿坑道等场合的安全防护和报警系统的潜力。为实现针对甲烷气体1653nm吸收峰特性的单色光源,采用金属有机化合物化学气相沉积外延和纳米压印等技术手段,从多量子阱外延材料设计和金属有机化合物化学气相沉生长到器件封装,研制了1653nm分布反馈激光器。器件性能达到了52dB边模抑制比、14.9%的外微分斜率效率、不大于12mA的阈值电流、匹配甲烷1653nm吸收带的0.116nm@20dB光谱线宽和稳定的光学与电学特性。基于该激光器,对体积分数为0.005～0.05的甲烷气体测试误差率不大于1.3%。结果表明,该器件能够应用于基于谐波法的痕量甲烷探测工程系统,且适应于批量制造。

Optical absorption method is effective for trace methane detection and is extensively used in foul gas measurement and alarm in case of coal mining tunnel. In order to obtain a monochromatic light source for detecting the methane absorption at 1653nm wavelength, a 1653nm distributed feedback （DFB）laser was obtained from multi quantum well material design and epitaxy to device package with technologies such as metal-organic chemical vapor deposition epitaxy and nanoimprint lithography. The laser demonstrated 52dB side mode suppression ratio, 14.9% external quantum efficiency, no more than 12mA threshold current, 0. llnm@ 20dB line width matching the absorption band of methane at 1653nm, and stable optical and electrical characteristics. Less than 1.3% error was obtained for detection of methane with gas volume fraction from 0. 005 to 0. 05, based on the DFB laser. The result shows that the device is suitable for trace methane detection in engineering by means of harmonic detection and can be manufactured in mass production.