Enhancing performance of metre-class telescopes by using photonic devices

Abstract

Over the last couple of years there has been increased interest in single-mode spectrographs, such as bulk optics-based single mode spectro- graphs and integrated photonic spectrographs. Such instruments have several key advantages over traditional (multi-moded) spectrographs: precision, small size, and related relatively low cost. However, the ground-based telescopes suf- fer from atmospheric distortions causing the light delivered by astronomical telescopes being multi-mode (seeing-limited) in nature. Current solutions to correct for atmospheric turbulence (such as adaptive optics) are ineffcient in the visible wavelength range and very expensive. Therefore, we use an alter- native solution and develop devices called photonic lanterns which convert a seeing-limited signal into multiple diffraction-limited spots and suit as a link between the telescope and a single-mode device. By means of the ultrafast laser inscription, we fabricate photonic lanterns on a glass chip. We optimised the design in order to achieve high throughput and created robust, highly effcient devices, which can greatly enhance the effciency and performance of the seeing-limited telescopes. Show more