SBIR-STTR Award

Multiple military and civilian applications of ultrafast laser technology become viable at a pulse energy level of 1 millijoule (mJ). While such levels have been demonstrated in femtosecond solid state amplifier systems, such as titanium-sapphire and ytterbium thin disk architectures, these systems rely on multi- element free space optical assemblies that are incompatible with demanding military deployments, as well as in industrial manufacturing venues. To date, 1 mJ pulse energy levels have not been achieved in fiber ultrafast pulse systems. To increase the pulse energy output of fiber systems, Raydiance proposes to advance the capabilities of the critical, final element in the amplifier chain—the pulse compressor. Raydiance will develop a 3 nanosecond (ns) pulse compressor that is compact, robust, and readily handles high pulse energy and average power. More specifically, Raydiance and its partner, OptiGrate, will design the optical geometry of a multi-pass chirped Bragg grating (CBG) compressor, demonstrate CBG devices specifically designed for the multi-pass configuration, and execute bench top experiments to validate the 3 ns compressor concept. In a Phase I Option, Raydiance will test the CBG devices in an end-to-end chirped pulse amplification system.

Keywords:
Laser, Laser, Compressor, Ultrafast, Optics, Femtosecond

Ultrashort pulse lasers have unique interactions with matter that include the ability to athermally ablate materials, create micron resolution texturing of surfaces, and provide diagnostic, sensing, and imaging capabilities. Of particular interest to the Navy is the potential use of ultrafast lasers for aircraft self-defense applications. One key component in the generation of laser pulses with sub-picosecond durations is the optical compressor. Compression systems used in commercially available ultrashort pulse lasers are typically bulky as they are an array of mirrors that form a path length of up to several meters. In this Phase II SBIR, Raydiance proposes to enhance a proven alternative technology known as a Chirped Bragg Grating such that they will compress 3 ns pulses down to 500 fs. In addition to a greatly reduced package size (where the beam path is just several centimeters), these devices have the benefit of stability as the beam path is largely through a solid state device. Key tasks in the base and option phases will demonstrate progressively capable gratings. In addition, architectures will be designed, built and environmentally tested to ultimately provide as a deliverable a proven, ruggedized compressor module that will greatly improve the USP laser’s SWaP characteristics.

Keywords:
ultrafast, ultrafast, LASER, femtosecond, CBG