A GaN-based vertical-cavity surface-emitting laser (VCSEL) has been demonstrated in an extended cavity structure. A VCSEL device had a long extended cavity, which consisted of a sapphire substrate as well as a GaN epilayer and had an integrated microlens on one side. High-reflection dielectric mirrors were deposited on both sides of the laser cavity. The laser was optically pumped and operated at room temperature. The VCSEL device lased at a low threshold excitation intensity of 160 kW/cm2. In contrast to a conventional microcavity-VCSEL structure, the VCSEL operated in multiple longitudinal modes with mode spacing consistent with its physical thickness.

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Abstract— Light extraction from InGaN‐based light‐emitting diodes (LEDs) on which microlens arrays were integrated using ray‐tracing methods was simulated. Enhancement of the total light extraction and beam shaping in the forward direction of the output of microlens‐integrated LEDs compared to conventional LEDs were observed. The diameter, curvature radius, and density of the microlens arrays on the LEDs were varied and the optimal conditions for external efficiency was determined.