We propose a polarization-insensitive and broadband subwavelength grating reflector based on a multilayer structure.The reflector has an overlapped high reflectivity（〉99.5%） bandwidth of 248 nm between the TE and the TM polarizations,which is much higher than the previously reported results.We believe this subwavelength grating reflector can be applied to unpolarized devices.
We report a novel lateral cavity surface emitting laser based on sub-wavelength high-index-contrast grating with in-plane resonance and surface-normal emission. The device is fabricated on a simple commercial wafer without the distributed Bragg reflector and it needs no wafer bonding. It exhibits a side mode suppression ratio of 23.0 d B and a high output power of 5.32 m W at 1552.44 nm. The specific single mode lasing agrees well with the band edge mode calculation of the grating. In 3D simulation, we observe obvious light output from the grating.
By combing artificial micro–nano structures,photonic crystals(PCs),with traditional semiconductor laser material to realize the dynamic collaborative control of photonic states and confined electrons,the band engineering of the PC has been confirmed.This brings new development space for the semiconductor laser,such as for low threshold and high efficiency.Based on a series of works by Zheng's group,this paper has reviewed kinds of PC lasers including electrical injection PC vertical cavity and lateral cavity surface-emitting lasers,and PC high beam quality lasers,to show that the PC is vital for promoting the continuous improvement of semiconductor laser performance at present and in the future.
