We report a new optomechanical pressure sensor using multimode interference (MMI) couplers with polymer waveguides and a thin p+-Si membrane. We have simulated device characteristics by the normal mode theory and the mode propagation method applied to deflection and strain of the membrane. The optical waveguide is made of a single-mode, rib type of NOA73/PMMA/SiO2 multi-layer system. The devices have been fabricated on the thin p+-Si membranes which are selectively etched using bulk micromachining. Device size is 0.4 mm (width)×13 mm (length) and the total thickness of the membrane is 7 μm. The device characteristics are measured using a He-Ne laser (λ = 632.8 nm) as a light source. High sensitivity of 8.2 ppm/Pa has been obtained in the range of 100 kPa.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Surfaces, Coatings and Films
- Metals and Alloys
- Electrical and Electronic Engineering