Research On Large Caliber Dual Wavelength Laser Collimation System

With the continuous development and breakthrough of the technology in the field of space optics,higher requirements are placed on the performance specifications of optical systems.Space optical system including laser collimation system is developing towards long focal length,large caliber,multi-spectrum and compact structure.Laser collimation systems have important applications in both space exploration and experimental production.In this paper,the optical system design,the development of optical components and the assembly of laser collimation system are studied by the large-caliber dual-wavelength laser collimation system with 400 mm diameter,focal length 8000 mm,laser source wavelength of 633 nm and 1319 nm.The large-caliber laser collimation system consists of a laser source and a collimating optical system.For the technical parameters of the laser collimation system,the off-axis Cassegrain structure is adopted.The initial structure is calculated according to the achromatic condition of the two-mirror system.The design result is obtained by ZEMAX software optimization,and the image quality is analyzed.The results show that the image quality satisfies the design index of the system.At the same time,in order to ensure that the two wavelength lasers source is output at the same point,a dual-wavelength coupling lens is designed,and the two-wavelength laser is coupled into the two-in-one beam combiner.The output power of the dual-wavelength laser is determined to meet the system light source design requirements.The processing method of the optical component of the large-caliber laser collimation system is described.The self-collimation method is used to detect the off-axis paraboloid primary mirror and the off-axis spherical method using the off-axis method without aberration points to detect the off-axis hyperboloid secondary mirror,which is measured by a 4D interferometer.The surface of each mirror completely meets the design requirements of single optical system error RMS ? ?/5.The main mirror and the secondary mirror of the large-caliber laser collimation system are installed and debugged respectively.The 4D interferometer is combined with a standard plane mirror to measure the image quality of the collimation system to meet the design specifications.In this paper,the lens coupling method is used to realize dual wavelength lasers confocal,and the laser output is more stable and efficient.The off-axis Cassegrain structural system is used,and the optical system focus is used as the input point of the light source,and the laser is output after being collimated by the system.