Study On High-stability Broadband Carbon Monoxide Laser

Carbon monoxide laser has a wide range of applications in the infrared spectroscopy and industrial processing as an important mid-infrared laser. Baseband CO laser covers the spectral range between 4.7μm and 8.4μm, and totally about 450 lines could be observed. Now, CO laser is one of the main light source for the infrared spectroscopy.Infrared absorption spectroscopy combined with nanosecond pulse heating technology can research the secondary structure of protein molecules and obtain a wealth of dynamic information of protein folding/open folding process. This research uses the CO laser as the probe light source. For the application the laser's wavelength and laser power output must be highly stable. And the laser is needed to be quasi-continuous tuning in the 5.1μm～7.8μm wavelength range.Therefore, there is no any kind of commercial CO lasers can achieve the requirements of the experiment on the market yet.This paper describes a low-temperature gas-flow high stability baseband carbon monoxide laser system. This laser uses a reflection grating as the frequency selecting component, and a dual high-voltage power supply. The laser discharge tube is cooled by liquid nitrogen. A temperature-controlled Invar resonator frame is used for passive frequency stabilization of laser. A filter circuit of laser power supply system is used, and a high-precision gas mass flow controller is applied in the laser system for obtaining a high operation stability. The laser output wavelength range from 5.1μm to 7.8μm with quasi-continuous tuning is achieved. The output power of the weakest lines available can be greater than lOmw. The long term drift of laser's longitudinal mode and laser power is inhibited. The ripple factor of the laser output power is effectively suppressed within 0.1%. The laser as a high-performance mid-infrared laser source, has important application value in the field of infrared absorption spectroscopy.