Optically decoupled dual-cavity VCSEL-modulator high-speed light source

Suny At Albany, Albany NY

Investigators

Abstract

Intellectual Merits High modulation frequency vertical cavity surface-emitting lasers (VCSELs) and dense VCSEL arrays are expected to change the whole paradigm of short-range interconnections ranging from silicon IC I/O's (and perhaps long intra-chip) to module- and board-level. The bandwidth of current-modulated laser diodes is limited to about 20 GHz by intrinsic dynamic processes but can be significantly increased by external modulation. In this case, optical feedback from the modulator to laser should be suppressed, for example, using optical isolator as in telecom applications. In this project, a novel method of optical decoupling of gain and absorber sections of a monolithic VCSEL-modulator emitter will be studied. The essence of the approach is in the suppression of the AC part of the optical wave reflected from the modulator section using a detuned Fabri-Perot cavity with quantum-confined Stark effect absorber. The work plan contains studies of the physics of the processes in the "decoupled" dual-cavity device, development of numerical models to assess relationships between the device parameters, such as resonance detuning accuracy, modulation depth and applied voltage swing; detuning, modulation bandwidth and frequency chirp, and optimization and demonstration of superior device characteristics. It is expected that the proposed VCSEL-Modulator emitter will demonstrate bandwidth of 40-100 GHz limited by parasitics of a low-power reverse-biased modulator p-i-n diode, and reduced frequency chirping which can be controlled from negative to positive. Broader Impacts: Broader impact of the proposed research is expected in education program that will benefit from the studies on physics of microcavities, VCSELs and modulators and the developed tools and technologies included into two PI's graduate level courses, direct participation in this research of graduate, undergraduate and historically under-represented in graduate education students and further development of interactive "Web-Tools" (http://www.albany.edu/~soktyabr/webtools) for design and virtual fabrication of optoelectronic devices.