UC Berkeley

Vertical-cavity surface-emitting lasers (VCSELs) have emerged as one of the most numerous and diverse categories of semiconductor laser, serving applications in telecommunications, imaging, ranging, and sensing. Improving the behavior of these devices, while extending them into new application spaces, is currently one of the most active fields of optoelectronics research. Concurrently, improvements in micro-optics, micro-mechanics, and low-noise experimentation have produced a field of cavity optomechanics studying the forces of confined light to excite or cool mechanical systems. This thesis explores the interaction of those fields by observing optomechanical forces acting on the MEMS-supported high-contrast grating (HCG) reflector in VCSELs. The unique properties of the HCG as a lightweight, ultra-high-reflectivity mirror enable optomechanical forces to be more salient in these devices than in typical distributed Bragg reflector (DBR) VCSELs. Through optical, electrical, and microscopy characterization methods, we demonstrate the use of radiation pressure to drive the mirror through current modulation and self-oscillation, notably producing a large amplitude oscillation resulting in broad-spectrum self-swept light. By demonstrating optomechanical effects in a single device, we simplify the traditional cavity optomechanics experiment and open a new design space in which to obtain the ingredients necessary for feedback-based optomechanical damping. Looking to both the applications of passive cavity optomechanics and those of wavelength-swept VCSELs, we highlight applications for these phenomena and design and fabrication changes to further explore and harness optomechanical forces in VCSELs. Additionally, we show the development of the first physics-based compact model of VCSELs, which enables simultaneous design of VCSELs and circuits to enhance VCSELs’ performance in communications, ranging, and optomechanics.