Parabolic telescope and spectrometer combination

Improvement of telescope resolution using a diffractive phase modulater

Metasurface, fluorescent microscopy and scanning near-field optical microscopy can improve the resolution of microscopes remarkably, while the resolution of the telescope remains unimproved constrained by its giant objective lenses and distant targets. Here we put forward a way to raise the resolution of telescopes simply by adding a binary optical thin surface around its focal plane. Simulation results show that the surface can raise the image quality in the Cassegrain and Kepler telescope. By nano-lathe, we fabricated a designed binary surface and experiment it in the Kepler telescope. The results are consistent with those of simulation results. More details of the calibrated target are resolvable on the image plane after applying the binary optical surface. It proves that the binary optic surface can make contribute to the resolution of the telescope, thus is beneficial in astronomy, military surveillance field.

Tuning of a high magnification compact parabolic telescope for centimeter-scale laser beams

Off-axis parabolic telescopes, widely used in astronomy and laser optics, if perfectly tuned, are virtually free from aberrations along the parabola's axis direction, but their alignment is very critical. We present a detailed method to align a high magnification off-axis afocal parabolic telescope. The method is composed of two steps: an initial pre-alignment using autocollimators, followed by a fine tuning with a collimated laser beam. Due to the large telescope magnification, the outcoming beam cannot be measured without being refocused. The beam is therefore reflected on a flat mirror and sent back through the telescope. This double-pass configuration allows the measurement of the beam quality without the need for large additional optics. In the fine-tuning step, a numerical simulation is also used to identify the degrees of freedom to be adjusted. The experimental results presented are obtained with one of the mode-matching parabolic telescopes of the gravitational wave interferometric detector Advanced Virgo.