Long-wavelength two-dimensional WDM vertical cavity surface-emitting laser arrays fabricated by nonplanar wafer bonding

We demonstrate the first long-wavelength two-dimensional wavelength-division-multiplexed vertical cavity surface-emitting laser array. The eight-channel single-mode array covers the C-band from 1532 to 1565 nm. The devices are fabricated using two separate active regions laterally integrated using nonplanar wafer bonding. We achieved single-mode powers up to 0.8 mW, 2-dB output power uniformity across the array, and sidemode suppression ratios in excess of 43 dB. This fabrication technique can be used to maintain the gain-peak and cavity-mode alignment across wide-band arrays and, with the use of nontraditional mirrors, can be extended to the fabrication of arrays covering the entire C-, S-, and L-bands as well as the 1310-nm transmission band.