SBIR Phase II: Relief-Free Infrared Diffractive Optics Based on Semiconductor Materials

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). This Small Business Innovation Research (SBIR) Phase II project will develop a new generation of relief-free thin-plate components of diffractive optics operating in the infrared region of spectrum. The diffractive optics employs volume phase holographic structures, which are optically recorded in semiconductor materials transparent at the infrared wavelengths using proprietary process of photo-modification for producing dramatic change of the material refractive index under illumination with low intensity light. Phase I of this project proved feasibility of the proposed concept by demonstrating photo modification of ZnSe infrared material and fabricating the first model components. The developed technology can be immediately applied to fabrication of diffractive optics, volume phase holographic gratings, and phase retardation plates for wavelengths up to 1.9 ýým, as well as antireflection layers for wavelengths up to 8 ýým. In Phase II project the technology will be optimized and applied to fabrication of the prototype components of infrared diffractive optics operating at longer wavelengths, including the important wavelength of CO2 laser 10.6 ýým and windows of atmospheric transparency 3-5 and 8-12 ýým. The developed photo-modification process is highly adaptable and creates a rich technology platform for fabrication of a broad range of products for a large variety of markets. Successful implementation of this technology will result in a new generation of high efficiency relief-free infrared diffractive optics and sub-wavelength components, including diffraction gratings, beam splitters, beam shapers, semiconductor materials with artificial birefringence, phase retardation plates and wave plates. The relief-free components of infrared diffractive optics based on semiconductor materials are capable to withstand high light intensities and perform complicated light management functions. Another important application is the fabrication of highly stable anti-reflection (AR) layers on infrared semiconductor optics. The market for infrared diffractive optics includes defense and airspace industry, laser industry, spectral devices, sensors and detectors, night vision optics, industrial process control, material processing, cutting and welding, environmental monitoring, medical diagnostics and surgery.