Photonwares produces fiber coupled tunable filters with industrial leading performance and value. These tunable filters are based on two proprietary technologies that utilize athermal multi etalon cavities or gratings, offering attractive features of covering near all wavelength, very low loss, unparallel low cost, set-and-hold operation, wide tuning range, ultrabroad band (visible to LWIR), minimal drift, and high power handle capability (10W). The platforms are also highly versatile that can be configured into versions of free-space, detector coupled, fiber coupled with MM, SM, PM types, and four-port add/drop module. The technology is protected by three pending patents. The applications include test, instrumentation, optical channel monitor network ROADM, Tunable receivers, EDFA flatting, gas sensors, breath analyzers, and military signaling.