Demonstration of electrically injected vertical-cavity surface-emitting lasers with post-supported high-contrast gratings

We experimentally demonstrate for the first time to our knowledge electrically injected vertical-cavity surface-emitting lasers(VCSELs)with post-supported high-contrast gratings(HCGs)at 940 nm.The HCG-VCSELs have two posts to support the air-suspended HCGs,which are realized by simple fabrication without critical point drying.The HCG-VCSEL achieves a threshold current of about 0.65 mA and a side-mode suppression ratio of 43.6 dB under continuous-wave operation at 25℃.Theoretically the HCG-VCSEL with a λ/2-cavity for the transverse magnetic polarization has a smaller effective mode length of 1.38.(λ/n).Thus,the relaxation reso-nance frequency can be increased by 16％compared with that of the conventional VCSEL.The modulation speed of 100 Gbit/s for the HCG-VCSEL is expected in the on-off keying modulation format.Our easy design of HCG-VCSELs has great potential for applications in optical interconnects,sensing,illumination,and so on.