Abstract
Integrated optics can provide compact and robust solutions for ground and space-based interferometry by integrating optical devices with different functionalities, such as spatial filters, combiners/nullers, and phase modulators, on a single chip. Lithium niobate (LiNbO3) has two distinct advantages over silica-based technologies, including good transparency further into the near-infrared (covering J, H, K, and L bands) and the ability to support electrically-controlled phase modulation through the linear electro-optic (EO) effect. The design, fabrication and preliminary tests of integrated optic components on LiNbO3 substrates for astronomical beam combiners operating in the H and L bands is reported. The components include single-mode waveguides of sufficient length for spatial filtering, symmetric junctions for wavelength insensitive power splitters/combiners, and electro-optic waveguide modulators for path-length control.
