The two coupled optical cavities within a vertical-cavity surface-emitting laser have the unique ability to modulate the spatial distribution of the longitudinal optical mode, without changing the total photon density in the laser cavities, by simultaneously directly modulating the two optical cavities exactly out-of-phase. A rate-equation analysis predicts that this condition, which we term push-pull modulation, exhibits a superior modulation response than that of conventional direct modulation. The push-pull modulation can enable high-speed operation with low power consumption, as a large modulation bandwidth can be achieved independent of the total photon density and/or the injection dc current. Experimental evidence of spatially changing the longitudinal mode is presented, and push-pull modulation at 2.5 Gb/s is demonstrated for the first time.
- Coupled cavity
- Semiconductor lasers
- Vertical-cavity surface-emitting lasers (VCSEL)
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
- Electrical and Electronic Engineering