Fabrication of proton-implanted photonic crystal vertical cavity surface emitting laser

By introducing the proton implantation(PI) process in the photonic crystal(PhC) vertical-cavity surface-emitting lasers(VCSEL) fabrication to confine the injection current in the devices can make the mesa process become pure plane technology. It reduced the fabrication difficult of the photonic crystal structure, simplified the fabrication processes, and improved the L-I-V characteristics uniformity of the devices. In the PI-PhC-VCSEL, the photonic crystal structure can control light beam and mode characteristics of the devices, when the current injection hole diameter is less than the center defect diameter of the photonic crystal. This effect in the PI-PhC-VCSEL can be used to optimize the threshold current and enhance the performance of the devices; it also can be used to realize high output power low threshold current single fundamental mode PI-PhC-VCSELs. A device with threshold current of 2.1 mA, output power larger than 1 mW, the divergence angle less than 7 was designed and produced. The device can operate with single fundamental mode with the injection current less than 12.5 mA and the effect of the photonic crystal in the PI-VCSEL has been demonstrated.