Abstract
Semiconductor diode lasers have been the preferred recording source for virtually every optical data storage system since their first reported use nearly a decade ago.1,2,3 Highly reliable, low-power devices are in wide use in consumer CD players while higher-power versions are used in write-once-read-many-times systems. With the emergence of Magneto-Optic media, higher demands are being placed on the power requirements for these devices due to the addition of the media erase cycle. In addition, there has always been a desire and, in many systems, a pressing need to improve the performance of the semiconductor diode laser in such areas as wavelength; mode stability and coherence (both spatial and temporal); beam divergence; power efficiency; and multiple sources on a single monolithic chip.4 The techniques and structures used to achieve diode laser performance improvements in these areas will be reviewed and discussed. In particular, a new class of grating surface emitter lasers5 allows one- and two-dimensional array geometries,6 with inherent stable, single-frequency operation imparted by the grating. These devices offer the advantages of narrow beam divergence, as well as the possibility of electronic steering of the beam. These properties may lead to new classes of high-performance, compact recording systems.