High-Power MWIR Fiber Amplifier

Next-generation IRCM applications would benefit from CW high-power (~kW) MWIR laser sources with good beam quality.  The lack of materials that lase in the MWIR region limits the development of these high power sources.  Laser sources that work in the MWIR suffer severe drawbacks that prevent their use in IRCM applications, mainly they have large-SWaPs due to their low electrical-to-optical efficiency, complex and large footprint setups and weight, high power consumption and, sometimes, the need for cryogenic cooling.  The development of QCL sources that lase in the MWIR is a promising step forward in solving the need of IRCM applications, however they are limited to medium power outputs and poor efficiency.  The development of all-fiber amplifying architecture to efficiently amplify QCL signals would reduce the system complexity, size and weight (low-SWaP).  Additionally, such amplifying systems can be scaled to high output powers and with careful design can be made to retain good beam quality. The proposed effort will demonstrate the feasibility of QCL signal amplification in rare-earth doped chalcogenide glass fiber in the MWIR.  The doped chalcogenide fiber will serve as the keystone of an all-fiber laser amplifier system capable of delivering high power and good beam quality.