- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
A Method of Human Eye Parameter Measurement Based on Laser Self-Mixing Interference
摘要： The eye is the most important sensory organ of the human body, and the cornea and anterior chamber are very important components In surgeries like vision correction, it is necessary to know the accurate corneal thickness and anterior chamber depth of human eyes. Their accurate measurement cannot only provide a reference for doctors, but also provide a strong guarantee of surgical results. In order to achieve high-precision measurements of human corneal thickness and anterior chamber depth, we develop an equivalent human-eye optical system and a measurement method for the thickness. This method designs an equivalent double-membrane system to simplify the physiological structure of the cornea and anterior chamber of the human eye and irradiate the double-membrane system through laser. The re?ected light returns to the laser cavity and the original light self-mixing interference, and a photodetector collects and processes the interference signals to obtain the corneal thickness and anterior chamber depth. The correctness of the theoretical calculations is veri?ed by the experimental system, and the measurement accuracy can reach the micrometer level.
关键词： self-mixing interference,anterior chamber depth,corneal thickness,confirmatory experiment,double-membrane system
更新于2025-09-23 15:21:01
-
Properties of self-mixing interference in terahertz distributed feedback quantum cascade lasers
摘要： The properties of self-mixing interference in terahertz distributed feedback quantum cascade lasers (THz DFB-QCLs) were studied by coupled wave theory and the multimode rate equation method. Under weak self-mixing optical feedback, the response behaviors of the DFB-QCLs are similar to those of Fabry–P(cid:2)erot lasers and can be described by the Lang–Kobayashi equations with a modi?ed feedback parameter. The amplitudes of the self-mixing power and frequency signals decrease with the increasing DFB coupling factor. Under strong feedback, new side modes arise, which broaden the laser linewidth. The number of side modes decreases with the increasing DFB coupling factor. The simulation also demonstrates that the maximum power mode of a THz DFB-QCL under strong self-mixing feedback is the minimum linewidth mode. These results support the development of self-mixing interferometers based on DFB-QCLs.
关键词： DFB-QCLs,Lang–Kobayashi equations,self-mixing interference,distributed feedback quantum cascade lasers,terahertz
更新于2025-09-12 10:27:22