Vertical-cavity surface-emitting laser with subwavelength photonic double heterostructures

Control of transverse modes in the oxide-confined vertical-cavity surface-emitting laser (VCSEL) is a key issue. We demonstrate a VCSEL with a double heterostructure high-contrast grating (HCG) as the top mirror to control the transverse mode characteristics. Compared with the common HCG-VCSEL with a uniform HCG, theoretically the proposed double heterostructure HCG-VCSEL can suppress the higher-order transverse modes. Experimentally, the double heterostructure HCG-VCSEL has a reduced spectral width and red-shifted fundamental mode compared with a common HCG-VCSEL with a uniform HCG, which is consistent well with the theoretical results. This work provides a new, to the best of our knowledge, approach to control the transverse modes of the VCSEL.