The broadband laser source and an active beam stabilization device for laser calibration systems

Purpose Currently, the calibration for astronomical telescopes requires a broad wavelength range of several hundred nanometers. Therefore, a simple and compact wavelength broadening device is applied to generate a variety of wavelengths. In addition, a beam stabilization system is designed to automatically correct the beam deviation due to vibration and temperature fluctuation.Methods We broaden the laser spectrum by nonlinear effect between the noble gas in a hollow-core fiber and the laser electric field. By selecting the species and pressure of the noble gases, one can control the spectral broadening. The active beam stabilization system consists of two mirror mounts with motorized actuators and two CCD cameras. After acquiring the centroid of the laser beam and comparing it with the target position, an algorithm is implemented to correct the beam pointing.Results Both experimental and simulation results show that the spectral range of the laser is greatly broadened. Besides, we have attained the phase of pulses. These parameters can be used to monitor the laser’s running status over time. The active stabilization system can quickly correct the deviation of beam pointing and simultaneously obtain the beam profile, allowing for nominally perfect control of the beam.Conclusion In our design, both the broadband laser source and beam stabilizer are involved in the laser calibration system, providing us with various wavelengths and a high-precision pointing with outstanding intrinsic long-term stability.