EXTERNAL-CAVITY SEMICONDUCTOR-LASER ARRAY INSENSITIVE TO PARAXIAL MISALIGNMENT

We report a tilted-mirror external-cavity gain-guided laser ar-ray who se output power is insensitive to small misalignments of the cavity el ements. This novel configuration delivers a near-diffraction-limited ( 1.5 times diffraction-limited) single-lobed beam in the entire current range without the need for realignment of the cavity. The light-curre nt characteristic is linear and kink free, with a higher efficiency co mpared with the free-running array. A compact graded-index lens design that can emit a collimated beam with a circular cross section is also described. (C) 1995 Optical Society of America