Beam Compressed System in Front of Wavefront Sensor
Miniaturization of wavefront sensor greatly limits the selection range of the light source and the receiving aperture of wavefront sensor, which could be overcome by placing an optical system in front of it. In this paper, we design an optical system with larger exit pupil distance and smaller optical length based on the Galileo telescope to compress the beam aperture of the light source, the variation regular and mathematical relationship between the compressing ratio, the focal length of the eyepiece, the focal length of the objective lens and the total length of the system are studied. Finally, the system is realized which the incident light wavelength is 1064 nm and the incident aperture is 70 mm, the compressing ratio is 10 times, the exit pupil distance is 30.593 mm, and the total length of the system is 261.395 mm. The results of simulation analysis and experimental verification indicate that the system achieves the purpose of compressing the aperture of the beam. The maximum RMS value of the system is 0.099λ, which meets the image quality evaluation standard. The large exit pupil distance of the system provides a large space for other optical elements, and provides conditions for expanding the application range of Hartmann sensor.