Compact stretcher/compressor for high power ultrafast laser based on volume chirped Bragg grating in PTR glass

The objective of this proposal is to develop the robust technology of a stretcher and a compressor for ultra short laser pulses. In Phase I OptiGrate demonstrated high quality stretching and compression by chirped Bragg gratings (CBG) fabricated in photo-thermo-refractive (PTR) glass. Significant improvement of a technology resulted in nearly diffraction limited quality of stretched and compressed pulses and diffraction efficiency up to 95%. For the first time 100 fs compressed pulses were achieved in CBG based CPA system. High average power (100 W) has been demonstrated as well. Phase II research and development will be directed towards enabling reliable manufacturing of CBGs designed for ultra short laser systems. The benefits of usage of such gratings are based on a compact geometry, unprecedented stability to optical radiation, high diffraction efficiency, absence of polarization dependence and durability to environmental conditions. However the most strategic importance of this technology is its scalability to large apertures and thickness which enable scaling to higher power and longer stretching. The specific target set for phase II of this project is demonstration of 1-ns stretching combined with large aperture 1x1 cm capable of compressing pulses with energies more than 20 mJ.