SBIR Phase I: Transparent Nanocrystalline Yttrium Aluminum Garnet (YAG) Ceramics

This Small Business Innovation Research (SBIR) Phase I Project, proposes to synthesize and consolidate nanocrystalline powders of yttrium aluminum garnet (YAG) for optical window applications. Optical window materials must meet extreme service requirements because they control the beam effectiveness and power output characteristics of laser/optical devices. Single crystal YAG is an ideal material for laser optics because of its excellent opto-mechanical properties. It is optically transparent in the wavelength region 200 to1200 nm (from ultraviolet to near-infrared) and from 2.5 to 6.0um (infrared). Unfortunately, single crystal YAG is costly and technically difficult to produce because of its high melting point (1970oC). One economically viable alternative is to fabricate transparent YAG ceramics using fine-grained polycrystalline powders. The field of nanomaterials offers excellent opportunities to fabricate optically transparent materials from polycrystalline powder, with opto-mechanical properties similar to single crystals. The use of polycrystalline YAG as a window material will revolutionize the laser industry by significantly reducing window cost. Transparent YAG has many applications in the laser and optics industries. It can be used as a window in high performance laser modules, wavefront analysis systems, beam collimation testers, spectrometers, laser power/energy meters, industrial turnkey laser systems for coding, 3D optical surface mapping, micro-machining, laser Doppler anemometers and imaging spectrographs. Lower cost laser systems will find more applications, especially in personal computers CD-ROMs with laser diodes, laser printers, and modems, which require optical isolation.