We report a technique for studying the absorption of optical radiation in layers of a semiconductor heterostructure by the method of probe radiation coupling. The studies are carried out using specially made isotype samples based on AlGaAs/GaAs, simulating an n-type doped laser waveguide with a concentration of 10¹⁷ – 10¹⁸cm⁻³. The main features of the experimental setup and calculation methods are described. A high (up to 95%) efficiency of light coupling into the waveguide and an error in measuring the absorption coefficient at a level of 0.1 cm⁻¹ are achieved. The possibilities of studying the polarisation and temperature dependences of radiation absorption by free carriers are experimentally demonstrated. It is shown that with an increase in temperature in the range 25 – 85C, the absorption in the samples increases by 15%.

我们报告了一种通过探测辐射耦合方法研究半导体异质结构层中光辐射吸收的技术。使用基于 AlGaAs/GaAs 的特制同种型样品进行研究，模拟浓度为 10 ¹⁷ – 10 ¹⁸ cm ^-3的 n 型掺杂激光波导。介绍了实验装置的主要特点和计算方法。^{光耦合到波导中的高效率（高达 95%）以及在 0.1 cm -1}水平上测量吸收系数时的误差达到。实验证明了研究自由载流子对辐射吸收的极化和温度依赖性的可能性。结果表明，随着温度在 25 – 85C 范围内升高，样品中的吸收增加 15%。