一种测量液体旋光特性的共光路外差干涉技术

为了提高旋光特性检测的灵敏度,设计搭建了一套基于塞曼效应的共光路外差干涉仪应用于旋光液体的旋光特性检测.采用塞曼效应激光器作为光源能发出两束正交线偏光,简化了实验装置的复杂性;且在系统中利用平衡检测与差动放大器,可降低激光器本身与外部环境所造成的大部分噪声,从而提高检测灵敏度.结果表明,对(0～50)mg/dL的低浓度葡萄糖水溶液的旋光特性测量,其检测灵敏度可达2.3×10-5(°).这种结构简单的干涉仪可应用于固态、液体或气态旋光物质的旋光特性分析中.

A common-path heterodyne interferometer technique for measurement of optical activity of liquid

In order to improve the detection sensitivity of optical activity, based on Zeeman effect, a common-path heterodyne interferometer was developed to measure the optical activity of liquid. In this heterodyne interferometer, a pair of correlated orthogonal linear polarized beam is emitted from a Zeeman He-Ne laser, which reduces the complexity of the optical system greatly. A balanced detector and a differential amplifier are integrated into this interferometer so as to reduce the excess noise induced by laser intensity fluctuation and external environments significantly. Thus, a shot-noise-limited detection of this interferometer can be achieved. The optical activity of glucose solution with concentration of(0～50)mg/dL was measured with this common-path heterodyne interferometer and the detection sensitivity was up to 2.3×10-5 degree. This simple heterodyne interferometer can be applied in the optical activity analysis of solid-state, liquid-state or gas-liquid material.