Parametrically Driven Intertial Sensing in Chip-Scale Optomechanical Cavities at the Thermodynamical Limits with Extended Dynamic Range (Case No. 2023-282) UCLA researchers in the Department of Electrical and Computer Engineering have developed a novel optomechanical accelerometer system with an integrated optical feedback system. This accelerometer is comprised of an optical oscillator acting on a mechanical oscillator. The radiation pressure of an integrated laser drives the mechanical system into oscillation, allowing for significant improvements in measurement sensitivity and dynamic range. Minute changes in mechanical resonance are used to measure specific force. The photonic crystal integrated onto the silicon-on-insulator has been optimized for maximum radiation pressure generation by reducing electric field leakage. The researchers simulated and subsequently introduced a method to plot the effective mechanical frequency as a function of laser driving wavelength. As the intracavity power increases, the mechanical frequency predictably shifts, allowing for precision measurements.
Intergrated Cavity Optomechanical Thermal Imaging Transducer (Case No. 2023-294)
UCLA researchers in the Department of Electrical and Computer Engineering have developed a highly sensitive method for measuring infrared radiation without the need for cryogenic cooling. This technology uses optomechanical oscillators integrated with transduction elements to collect external radiation. This causes structural deformations in the material that are proportional to the amount of collected radiation. The device operates at room temperature as the optomechanical oscillators are laser driven, allowing for strong transduction. This high sensitivity method has wide ranging applications in imaging and electronics.
Dual-Stage On-Chip Optical-To-Microwave Low-Noise Synthesizer (Case No. 2022-059) Professor Chee Wei Wong and his team have addressed the challenges in this field by leveraging a dual-stage frequency division approach. Their innovation utilizes a dual-stage frequency division process to transfer frequency stability from an on-chip laser to microwave frequencies. This technology enables the generation of ultra-low-noise microwave signals between 1 and 40 GHz, with a phase noise of -154 dBc/Hz at a 10 kHz offset. The synthesizer incorporates an on-chip laser locked to an ultrahigh-Q microcavity and utilizes an octave-spanning THz repetition rate microresonator frequency comb for the first stage of division. The second stage employs a hybrid photonic-RF approach with a tunable effective division factor. This innovation enables the synthesis of microwave frequencies between 1 and 40 GHz while achieving remarkable phase-noise performance.