Mid-Infrared Fiber Coupler for Multiband Infrared Countermeasure (IRCM) Lasers Navy SBIR FY2011.2 Sol No.: Navy SBIR FY2011.2 Topic No.: N112-089 Topic Title: Mid-Infrared Fiber Coupler for Multiband Infrared Countermeasure (IRCM) Lasers Proposal No.: N112-089-0827 Firm: IRFLex Corporation 300 Ringgold Industrial Parkway Danville, Virginia 24540-5548 Contact: Francois Chenard Phone: (434) 483-4304 Web Site: www.irflex.com Abstract: Compact high power (>100 W) mid-infrared (2-5 microns) lasers are highly desired for military applications, such as infrared counter measures (IRCM). Semiconductor lasers, such as quantum cascade lasers (QCLs), are efficient compact sources that operate in the desired wavelength range. However, these lasers are currently limited in output power (~5 W). To achieve high powers, the output of several lasers must be merged. Free-space optics can be used to combine the lasers. Such combining system can suffer from vibrational induced misalignment in military vehicles or aircrafts. Couplers that are fiber-based would be ideal devices, since they are compact, environmentally stable and lightweight. Unfortunately, available fiber couplers are made from silica glass, which absorbs light below 2 microns. Mid-infrared transmitting fibers, conversely, have been demonstrated to transmit light in wavelengths beyond 10 microns. These fibers have been used in IRCM systems with great success and can be used to develop power couplers in the desired wavelength band. The proposed work will demonstrate feasibility of developing innovative mid-infrared fused-fiber devices designed for concatenating laser wavelength between 2-5 microns. Such technology can be the platform for developing broadband couplers for mid-infrared lasers, such as quantum cascade lasers, to achieve high power outputs. Benefits: The proposed fused fiber bundle coupler is targeted primarily at military applications and supports directly the advancement of the future IRCM systems and remote sensing of targets and threats. The Phase II work will specifically deliver a prototype fused fiber coupler with test results in a laboratory. Upon successful completion of the Phase II effort, IRflex will have developed the expertise and know-how on the modeling and fabrication of efficient fused fiber bundle coupler for combining the power of several mid-infrared lasers into a single fiber with high output power > 100W. The coupler can also be used to combine lasers of different wavelength to produce a broadband mid-infrared source that can be used in explosive and chemical analysis. IRflex will be in a unique position to develop and commercialize novel mid-infrared fiber bundle coupler for military (IRCM), chemical sensing (molecular spectroscopy), and biomedical (laser surgery) applications. Return