Research Of VCSEL-based TDLAS Methane Detection System

The research and development of TDLAS gas detection technology widely use the DFB side emitting laser as detection light source.This technology has high power consumption and large volume,which limit the application of TDLAS detection technology in power sensitive situations.Vertical plane emitting laser has advantages of high efficiency,low power and small volume.It can effectively decrease the power consumption and volume of laser gas detection technology by replacing the DFB laser.The theoretical basis of TDLAS gas detection technology with VCSEL laser is analyzed.According to the gas absorption spectroscopy and the luminescence characteristics of the VCSEL laser,the detection laser wavelength of methane gas was selected.TDLAS-WMS wavelength modulation technology and harmonic detection technology were analyzed and derived the process of detecting signals during detection.It provides theoretical basis for the actual VCSEL-based TDLAS detection technology.Based on the tuning characteristics of VCSEL and the principle of TDLAS detection technology,the software simulation of TDLAS gas detection technology is completed.In this paper,the process of signal changes in TDLAS gas detection was studied in detail and transplanted to the hardware platform to complete the hardware simulation of the detection technology.After the guidance of theoretical analysis and the study of simulation results,Suitable tunable VCSEL and photoelectric detector and phase-locked amplifier device are selected.Finished the optical and electrical design of the detection system,a VCSEL-based TDLAS system for methane gas detection is developed.