Apparatus and Methods for Photonic Integrated Resonant Accelerometers

Micro-electromechanical systems (MEMS) accelerometers, essential in measuring acceleration forces, have a significant role in a variety of sectors from consumer electronics to automobiles, aiding in stability control, performance monitoring, and enhanced user experience, among others. However, the need for improved precision, long-term stability, and low SWaP-C (size, weight, and power and cost) demands continuous advancements in the technology employed. The key issue with traditional methodologies lies in their limited scale factor and relatively high SWaP-C. The measurement of resonant frequencies in small tethers attached to a large proof mass has been a persistent challenge, affecting the sensitivity and precision of the accelerometers. The current approaches also struggle to maintain a balance between delivering high performance and keeping the SWaP-C low, thereby creating a need for a better, more efficient solution.

Technology Description

The accelerometers utilize photonic integrated circuit technology and standard micro-electromechanical systems (MEMS) technology to achieve high sensitivity, long-term stability and low size, weight, power, and cost (SWaP-C). The innovativeness lies in the use of optical transduction to enhance the scale factor of traditional MEMS resonant accelerometers by accurately measuring the resonant frequencies of diminutive tethers attached to a large proof mass. Examples of these accelerometers deploy ring resonators and linear resonators to assess tether frequencies. What sets this technology apart is the excellent precision it brings to measure frequencies of tiny tethers, which could be around 1 μm, attached to a large proof mass, around 1 mm. This design results in improved scale factor for traditional MEMS resonant accelerometers. By this integration of photonic integrated circuit technology with MEMS technology and optical transduction, these accelerometers offer high sensitivity and unbeatable stability while maintaining low SWaP-C.