Wide Waveband, Large Aperture, Trichroic Beamcombiner

Recent developments in hardware-in-the-loop systems for simulation and test of defense-critical sensors have led to requirements for optical beam combiners transmitting near infrared and Ka bands but reflecting long-wave infrared bands. Many candidate materials fall short of meeting specifications in these wavelength regions. By using innovative inhomogeneous (or rugated) index of refraction profile filter design techniques, needle-synthesis techniques, and a state-of-the-art deposition tool, it will be possible design and fabricate a trichroic beam combiner passing 1064 nm, blocking the LWIR, and passing the Ka band. This will be accomplished through achieving the Phase I technical objectives of formulating and theoretically modeling initial designs for rugate coatings to met spectral requirements, depositing beam combiner coatings on small witness pieces to develop process monitoring procedures and evaluating environmental durability (heat, humidity shift, abrasion) and iterating the design to compensate as needed.