提出一种激光器发射波长和功率控制与稳定的方法, 研制出波长范围在9.19~9.77 μm, 可应用于葡萄糖检测的中红外波长可调谐CO2激光器, 发射光谱半波宽度为4 cm-1, 光谱分辨率达到2.7×104, 最高功率为800 mW, 功率波动性＜0.8%。 根据葡萄糖在中红外指纹谱波段的吸收特性, 选择激光器发射光谱9R和9P带的1 081, 1 076, 1 051, 1 041和1 037 cm-1作为测量波长, 利用ATR传感器测量了PBS溶液中葡萄糖浓度。 结果表明五个测量波长下的吸收度与葡萄糖浓度呈现良好的线性关系(R2＞0.99, SD＜0.000 4, P＜0.000 1), 且该波长可调谐激光光谱测量系统的灵敏度是传统FTIR光谱仪的4倍左右。

The authors proposed a method of control and stabilization for laser emission wavelengths and power, and presented the mid-infrared wavelength tunable laser with broad emission spectrum band of 9.19~9.77 μm, half wave width of 4 cm-1, spectral resolution of 2.7×104 and max power of 800 mW with fluctuation ＜0.8% in the present paper. The tunable laser was employed as the light source in combination with ATR sensor for glucose measurement in PBS solution. In our experiments, absorbance at the five laser emission wavelengths, including 1 081, 1 076, 1 051, 1 041 and 1 037 cm-1 in the 9R and 9P band of the laser emission spectrum, all correlates well with the glucose concentration (R2＞0.99, SD＜0.0004, P＜0.000 1). Especially, the sensitivity of this laser spectroscopy system is about 4 times as high as that of traditional FTIR spectrometer.