Broad-area Vertical-cavity Surface-emitting Lasers Research Articles

Single mode power and modal behaviour in buried vertical-cavity surface-emitting lasers

Modal behaviour in buried vertical cavity surface-emitting lasers (VCSELs) is simulated using the two-dimensional beam-propagation-method (BPM) model. For broad-area VCSELs a tapered cavity strongly enhances the modal losses of the higher order modes and increases single mode output power. However, for small-area VCSELs it reduces output power. Furthermore, passive antiguide-region structure increases modal discrimination. An optimum index difference ( Delta =0.084) is needed to achieve the maximum modal discrimination in the step-profile case. A new parameter, relative modal loss difference, is introduced to describe the mode competition, which can be used to estimate single-mode operation regime. The parameter can also be used in the external cavity case. Simulations show that a carefully designed 16 µm diameter antiguide-region lasers can operate in single mode in the whole bias region.

Design and characterization of In/sub 0.2/Ga/sub 0.8/As MQW vertical-cavity surface-emitting lasers

The device design, material characterization, and performance of optimized vertical-cavity surface-emitting lasers (VCSELs) are presented. The basic design goal was to increase the output power of the lasers without greatly increasing the low threshold current reported in earlier devices. The material characterization was performed by measuring in-plane lasers and broad-area VCSELs made from the same material as the small VCSELs. For 10- mu m-square devices, outputs over 3 mW, device operation over 100 degrees C, 6% wall-plug efficiency, threshold voltages under 3 V, and threshold currents under mA are reported.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Two-dimensional phase-locked arrays of vertical-cavity semiconductor lasers by mirror reflectivity modulation

Coupling of two-dimensional (2D) vertical-cavity surface-emitting lasers (VCSELs) to give a coherent supermode is described. The top metal layer of a stained-layer InGaAs quantum well VCSEL structure was patterned laterally by depositing various metals with different optical reflectivities. This lateral reflectivity patterning defined a 2D laser array sharing the same ‘‘supercavity’’. It is shown that these 2D arrays oscillate in a stable single, coherent 2D supermode. This was achieved with a simple planar process and without significant deterioration of threshold current and efficiency relative to an equivalent broad-area VCSEL.