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

Abstract

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°C. 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 resonance 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.