Recent Progress in Polarization-Bistable VCSELs and Their Applications to All-Optical Signal Processing

Abstract

We summarize recent results of research on polarization bistable vertical-cavity surface-emitting lasers (VCSELs) and their applications for all-optical signal processing. 980-nm polarization bistable VCSELs with an oxide confinement structure were fabricated for low power consumption operation. The threshold current of the VCSEL was reduced to 0.22 mA and all-optical flip-flop operation was demonstrated at a record low bias current of 0.85 mA. We proposed an optical header processing system using a 1.55-μm polarization bistable VCSEL as an all-optical AND gate and a holding element. The payloads of 40-Gb/s NRZ format were send to designated ports depending on the state of a selected bit in the 4-bit header with a 500-Mb/s RZ format. In these operations, the input optical power for the VCSEL was much smaller than the output power. Therefore, the polarization bistable VCSEL is a promising candidate as an all-optical bistable device to realize an all-optical packet router.