SBIR Phase II: Liquid-Crystal Waveguides for Optical Integrated Circuits

This Small Business Innovation Research (SBIR) Phase II project will reduce mechanical external-cavity diode lasers to a centimeter-sized waveguide chip using a novel giant electro-optic effect. The device, a waveguide external-cavity semiconductor laser (WECSL), will be environmentally robust, compact, entirely electro-optic and capable of continuous, mode-hop-free tuning over 100 nm in fewer than 5 milliseconds. The laser will also exhibit a side-mode-suppression ratio of 40 dB and a (fast) linewidth of ~200 kHz. In Phase II we will demonstrate advanced prototype WECSLs, develop critical manufacturing processes, and perform basic environmental qualifications. We will also conduct research allowing the laser to sweep over a 50 nm band at a rate of 5 kHz. The low-cost technology platform of WECSLs, and their precision performance specifications could enable laser-based sensors to assume a prominent role in commercial applications. In biophotonics, tunable lasers can replace broadband light sources and enhance the performance of optical coherence tomography instruments that measure the tissue layers in the human retina and the vascular system. Distributed fiber sensing arrays greatly benefit from tunable lasers that probe Bragg sensors spaced along the fiber. Distributed fiber sensors needing low-cost tunable lasers are being developed for chemical and biological sensing, pressure sensing, and vibration, strain and temperature sensing for a wide variety of monitoring applications such as homeland security; civil structures such as buildings, bridges, and dams; oil wells and pipelines; electrical power lines; aircraft and spacecraft; and all-optical shipboard sensing.