Compact stretcher/compressor for high power ultrafast laser based on volume chirped Bragg grating in PTR glass Navy SBIR FY2008.1 Sol No.: Navy SBIR FY2008.1 Topic No.: N08-047 Topic Title: Compact stretcher/compressor for high power ultrafast laser based on volume chirped Bragg grating in PTR glass Proposal No.: N081-047-0519 Firm: OptiGrate (LP&T, Inc.) 3267 Progress Drive Orlando, Florida 32826-3230 Contact: Vadim Smirnov Phone: (407) 590-4889 Web Site: www.OptiGrate.com Abstract: A compact stretcher/compressor for high power ultra short fiber laser system with chirped pulse amplification is proposed on the basis of longitudinally chirped volume Bragg gratings in photo-thermo-refractive (PTR) glass. Efficiency of compression will exceed 80% for average power scaling to the kilowatt level. Effects of refractive index uniformity in PTR glass and optical aberrations in a hologram recording system will be studied. High quality of stretched and compressed beams are provided by high quality of PTR glass with extreme optical homogeneity and extreme low absorption combined with an advanced technique of hologram recording. The proposed stretcher/compressor will demonstrate high tolerance to vibrations, thermal gradients and harsh environment. Benefits: Development of a technology for a compact, robust and efficient device for stretching and compression of short laser pulses in systems with chirped pulse amplification (CPA) will enable great expansion of application of femtosecond lasers for both military and commercial applications. The most expensive, most bulky, and least reliable element in high power femtosecond lasers with CPA is pulse compressor. The proposed solution will enable a replacement of this complex element with a monolithic element which is a volume Bragg grating with linear increment of period in direction of beam propagation. This element produces both stretching and compression of laser pulses, has size order of magnitude less in comparison to a conventional compressor, cannot be misaligned and tolerable to high power laser radiation and harsh environment. These elements should find wide applications in both military and induatrial fields. Return