Atsushi Tajiri

High-power 200 mW 660 nm AlGaInP laser diodes with low operating current

We have newly introduced a two-step-growth structure and a ridge stripe with steep sidewalls formed with a dry-etching process in the fabrication of a buried ridge stripe structure of a high-power 660 nm laser diode instead of a conventional three-step-growth structure and a ridge stripe with gentle sidewalls formed with a conventional wet-etching process in order to reduce the operating current. We have found that the two-step-growth structure provides better heat dissipation and the dry-etched ridge stripe structure offers higher characteristic temperature. The operating current under pulsed 200 mW at 70°C of the fabricated laser diode is 270 mA. This is the lowest value ever reported so far, to our knowledge. These laser diodes exhibit a kink level and a maximum light output power of 220 mW and higher than 300 mW, respectively. These laser diodes have also operated stably for 1500 h at 70°C with a light output power of 200 mW under the pulsed condition.

High-Power, 790 nm, Eight-Beam AlGaAs Laser Array with a Monitoring Photodiode

A high-power, 790 nm, eight-beam individually addressable AlGaAs laser array on 50 µm centers with a monitoring photodiode has been developed for high-speed data transfer in optical memory systems. The maximum output power of each element is over 80 mW. When eight elements are simultaneously operated at 20 mW in APC (Automatic Power Control) mode using the one-beam monitoring control, the total light output variation is less than 7% at a heatsink temperature between 10 and 50°C.

Fundamental transverse-mode 150-mW semiconductor laser for an SHG light source

A highly reliable, 150 mW high-power semiconductor laser that oscillates at a wavelength of 860 nm has been developed. This device has a 0.7 jim thick p-cladding layer, a 900 jim long cavity length, and current-blocking regions near the cavity facets for high output power and high reliability. Stable, fundamental transverse mode and single longitudinal mode operation were obtained up to 230 mW, and the maximum output power was 350 mW under CW operation. Stable operation under 150 mW at 50°C was confirmed for more than 2000 hrs.

100 mW, Four-beam Individually Addressable Monolithic ALGaAs Laser-diode Arrays

Four-beam individually addressable monolithic AlGaAs laser-diode arrays have been developed in which each laser element can emit over 100 mW of output power in single-mode operation. The structural features of this laser include current-blocking regions near the facets and a long cavity length to obtain higher power, as well as a cBN heatsink and a 70 micrometers - thick laser chip to improve thermal crosstalk between laser elements. The maximum output power of each laser element is about 200 mW and the lasing wavelength is about 834 nm. Thermal crosstalk between 100 micrometers -spaced neighboring elements is only 1.0% at 100 mW.