This Small Business Innovation Research (SBIR) Phase I project will investigate the fabrication of volume holographic grating filters for retro-reflection in the 1.55 micron band with sufficient bandwidth to provide wavelength monitoring over a 1 to 2 nm range. This would be sufficient to monitor any signal over the full channel width of a wavelength division multiplexed (WDM) optical network, addressing a need for external wavelength references to insure that the lasers do not drift out of their assigned channels. Current alternatives are not feasible for integration into telecom equipment because of size constraints or technical limitations. Phase I will focus on increasing bandwidth on current holographic grating filters and decreasing input signal requirements with higher detector sensitivity. A prototype design will be made. Anticipated commercial applications of this technology include network monitors for WDM transmitters and accurate wavelength laser sources, both for telecom and other laboratory applications. In addition, filters can be used for remote sensing, i.e., eye-safe LIDAR, instrumentation, and spectroscopy.
