Optical and electronic devices for optoelectronic integrated circuits have been extensively studied, and now, more efforts for the conversion between optical and electrical signals are accordingly required. In this work, a silicon (Si)-compatible optically drivable III-V-on-Si metal-oxide-semiconductor field-effect transistor (MOSFET) is studied by simulation. The proposed optoelectronic device provides a strong interface between the optical and the electronic platforms as a key component of the optical interconnect. The optically driven MOSFET device is analogously analyzed into a photodetector and its complementary device, getting rid of receiver circuitry, which improves the integration density and simplifies the fabrication processes. To realize the optical switching with maximized photo-sensing region, a bottom gate is formed to modulate the channel, where germanium (Ge) and gallium arsenide (GaAs) are the active materials on Si platform. Both direct-current (DC) and alternating-current (AC) performances of an optimized device are evaluated.
Molecular optical imaging is a widespread technique for interrogating molecular events in living subjects. However, current approaches preclude long-term, continuous measurements in awake, mobile subjects, a strategy crucial in several medical conditions. Consequently, we designed a novel, lightweight miniature biosensor for in vivo continuous optical sensing. The biosensor contains an enclosed vertical-cavity surface-emitting semiconductor laser and an adjacent pair of near-infrared optically filtered detectors. We employed two sensors (dual sensing) to simultaneously interrogate normal and diseased tumor sites. Having established the sensors are precise with phantom and in vivo studies, we performed dual, continuous sensing in tumor (human glioblastoma cells) bearing mice using the targeted molecular probe cRGD-Cy5.5, which targets αVβ3 cell surface integrins in both tumor neovasculature and tumor. The sensors capture the dynamic time-activity curve of the targeted molecular probe. The average tumor to background ratio after signal calibration for cRGD-Cy5.5 injection is approximately 2.43±0.95 at 1 h and 3.64±1.38 at 2 h (N=5 mice), consistent with data obtained with a cooled charge coupled device camera. We conclude that our novel, portable, precise biosensor can be used to evaluate both kinetics and steady state levels of molecular probes in various disease applications.