Semiconductor Laser Arrays Research Articles

Near-field and far-field patterns of phase-locked semiconductor laser arrays

A gain-guided phase-locked semiconductor laser array has been observed to emit a single narrow lobed far-field radiation pattern up to 70 mW, at which power level it exhibits a distinct change. We show that this effect results from a new phase-locked mode attaining threshold; the original mode remains phase locked above this power level.

Far-field distribution of semiconductor phase-locked arrays with multiple contacts

Experimental results of far-field patterns of semiconductor laser arrays with multiple contacts are reported. It is found that, by tailoring the distribution of the currents through the array elements, narrow single-lobe patterns—which are more useful in most applications—can be obtained from arrays that usually operate in a double-lobe mode. A diffraction-limited 1.8°-wide far-field pattern was obtained from a three-element array.

Continuous wave high-power, high-temperature semiconductor laser phase-locked arrays

Continuous wave GaAlAs semiconductor laser arrays are reported to emit 585-mW/facet cw optical output power at room temperature. The lasers operate over 100 °C with output powers in excess of 200 mW/facet cw. Laser thresholds are as low as 130 mA, differential quantum efficiencies exceed 60% for some devices, and very high total power conversion efficiencies of over 20% are observed.

P-n Junction Lasers for Communication Systems

Secure ground-to-ground communication links, communication from satellites and space probes, and coherent optical logic in high-speed integrated computers lie within the realm of semiconductor single lasers or laser arrays. Lasers of this type have the advantage of extremely small size, ease of direct modulation, and high efficiency. Ruggedness and simplicity of pumping promise high reliability for military electronics. A discussion is presented on design considerations, technological problems, and performance of p-n junction lasers for short range communication systems. After a brief review of fundamental principles for lasing action in semiconductors, an account is presented of previously unpublished technological procedures required to achieve GaAs laser diodes with high output in the coherent beam at a high pulse rate required to operate a pulse code, modulated voice transmission system. A description is given of wafer preparation, diffusion of extremely planar p-n junctions, and the formation of ohmic, low-resistance area contacts. Measurement techniques to determine the performance characteristics of these lasers with respect to such factors as threshold current density, maximum output power, external quantum efficiency, spectral distribution, and linewidth of emitted radiation are discussed.

Semiconductor laser arrays and their characteristics

Semiconductor laser arrays and their characteristics