High-power near-diffraction-limited tapered amplifiers at 1064 nm for optical intersatellite communications

The realization of high-power tapered amplifiers at 1064 nm on a low-modal gain structure is presented. More than 1.5-W continuous-wave optical output power at 3-A injection current is achieved with only 13-mW input optical power and a near-diffraction-limited output beam quality. The use of a low-modal gain structure in conjunction with a very low AR-coating value avoids the addition of cavity spoilers. The implementation of such amplifiers in an optical intersatellite communication system is studied. The devices showed excellent resistance to 160-krad proton irradiation. Preliminary aging tests on broad-area laser diodes demonstrate extrapolated lifetimes as long as 20000 h at 50/spl deg/C.