Integrated optical components (mostly single-mode fibers and couplers) can be used to achieve several functions that are needed in interferometry: coherent beam transportation and recombination, pathlength modulation and control for fringe tracking and double Fourier interferometry, spatial filtering of the wavefront and interferogram calibration. Their potential is assessed and the main problems encountered in their implementation are discussed: dispersion, polarization behavior, and especially starlight injection.
The 400 keV proton implantation with a fluence of [Formula: see text] ions/cm2 was applied on the [Formula: see text] co-doped phosphate glass to fabricate a planar waveguide structure. The mode profile at the end face of the waveguide was measured by the end-face coupling technique. The energy loss profile of the energetic protons was calculated by the SRIM 2013. The refractive index distribution was simulated by the reflectivity calculation method. Based on these results, the formation theory of the planar waveguides was discussed through simulating the energy loss distribution and analyzing the reconstructed refractive index profile, which could be used for applications in the future integrated optical systems.
Fabrication of an integrated optical filter using a large-core multimode waveguide vertically coupled to a single-mode waveguide
