Power, Bandwidth, and Efficiency of Single VCSELs and Small VCSEL Arrays

Single-emitter vertical-cavity surface-emitting lasers (VCSELs) and multiple-emitter VCSEL arrays designed for emission at 980 nm, and with large oxide aperture diameters (phi) from similar to 10.5 to 33.5 mu m and with phi of similar to 7.5 mu m that are configured in three-emitter and seven-emitter electrically parallel triangular and hexagonal arrays, respectively, have record bandwidths and optical output powers for VCSELs with such large cumulative emitting areas. We demonstrate room temperature (RT) maximum small-signal modulation bandwidths (f(3dBmax)) of 26.6 to 18.6 GHz with corresponding continuous wave (CW) optical output powers (L) of 16.2 and 47 mW for VCSELs with phi similar to 13.5 and 33.5 mu m, respectively. For parallel 980 nm triple and septuple arrays with phi similar to 7.5 mu m for each VCSEL, we demonstrate RTf3dBmax of 25.5 and 24.8 GHz with corresponding CW L of 22.7 and 50.1 mW, respectively. We perform a comparative analysis of the RT results, which consist of standard static light output power-current-voltage (LIV) characteristics to determine the typical VCSEL figures-of-merit including wall plug efficiency (WPE), LI slope efficiency, spectral emission versus current (I), and small-signal frequency response curves. We examine the tradeoffs in optical output power, small-signal modulation bandwidth, and WPE for the various VCSEL designs, and find that while the combination of f(3dBmax) and L are record values for single VCSELs and VCSEL arrays, these parameters fall off as the cumulative VCSEL array area increases to emit higher overall optical power.