We present and theoretically investigate a mid-infrared (mid-IR) optical sensor based on a Ge11.5As24Se64.5 one-dimensional (1D) photonic crystal micro-bridge cavity.
A calculated sensitivity of as high as 2280 nm/RIU (refractive index unit) is achieved with a resonant wavelength of 4132 nm.
The figure of merit of the device for sensing is extremely high at ~930,000.
Furthermore, the sensing part of our device (50 × 3 μm2) is only 1/1000 that of the recently reported microring mid-IR sensor (larger than 600 × 360 μm2).