Abstract

Direct frequency doubling of a laser diode output can be an efficient technique for generating coherent blue radiation. Until recently, however, the doubled output power has been low¹ due to limited pump power available from GaAlAs laser diodes. To increase the available fundamental power, coupled laser diode arrays, externally injection locked to obtain diffraction-limited operation, have been used² to achieve 0.72 mW of 421-nm output in a single pass.

© 1989 Optical Society of America