Monolithic Four-Beam Semiconductor Laser Array with Built-in Monitoring Photodiodes

A four-beam semiconductor laser was developed in which a monolithic array of four individually addressable GaAlAs high power lasers and four integrated Si photodiodes for monitoring the light output power of laser beams are housed in a single package. The main specifications are as follows; output power per beam, 40 mW; wavelength, 830 nm; and monitoring current at 30 mW, 100 ˜200 µA. Thermal analysis by numerical simulation was carried out and compared to experimental values observed during simultaneous operation of the multiple elemental lasers. The operating lifetime is estimated to be more than 10, 000 hrs at room temperature.