SBIR Phase I: Electro-Optically Tunable Diode Lasers for Sensing Applications

This Small Business Innovation Research (SBIR) Phase I 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 of 100 nm in 500 ms. The laser will also exhibit a side-mode-suppression ratio of 40 dB and a (fast) line width of ~100 kHz. The broader impacts/commercial potential of this project will be a low-cost technology platform of WECSLs, and their precision performance specifications will 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. Low-cost tunable lasers are also needed for environmental sensing of toxic industrial compounds and safety monitoring for lower explosive limits in mining and other industrial operations. This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).