SELF-ALIGNED PHOTONIC CRYSTAL VERTICAL-CAVITY SURFACE EMITTING LASER BY PHOTOLITHOGRAPHY TECHNIQUE

Abstract

In this paper, we report on single-mode operation of originally multi-mode oxide VCSEL by using etched photonic crystal air holes and unique trench structure. The device fabrication utilized conventional photolithography; with simplified lithography step of self-aligning the photonic crystal and trench structures to the laser aperture for efficient and vigorous device processing. The fabricated photonic crystal VCSEL with trench device exhibits a single-mode output power of 0.7 mW, threshold current of 3.5 mA, slope efficiency of 0.10 W/A, and continuous single-mode output spectra at wide operating current range. The results are compared with conventional multi-mode oxide VCSEL of similar device geometry. It is demonstrated that a highly confined and continuous single mode operation of VCSEL can be achieved by etching of photonic crystal air holes at the laser facet using a simple photolithography technique.