Recent Advances in Photonic Crystal Surface Emitting Lasers

In recent decades, photonic crystal surface-emitting lasers (PCSELs), a novel design of semiconductor light sources, have shown huge performance improvement. Based on compact semiconductor heterostructures, PCSELs have not only achieved near diffraction limit beam divergence but have also realized single-mode lasing from a broad emission area. Thanks to its planar cavity design, PCSEL cavities can integrate confinement structures laterally, which can potentially achieve performances otherwise unachievable in the current semiconductor lasers. This paper reviews recent advances in PCSELs, including the high-power PCSELs, laterally confined PCSEL design, PCSEL cavity size scaling for high speed, narrow laser linewidth, and coherent PCSEL arrays.