Physics / mechanism
Sensing and imaging convert physical phenomena—photons, pressure, temperature, magnetic flux, acoustic waves—into electronic signals. Core device physics spans photoelectric conversion (silicon photodiodes, CMOS image sensors, InGaAs arrays), MEMS transduction, and RF/mmWave reception. Key performance parameters: quantum efficiency (QE), noise-equivalent power (NEP), dynamic range, pixel pitch, frame rate, and spectral bandwidth. CMOS image sensors dominate visible-light at sub-1 µm pixel pitch; InGaAs covers SWIR (900–1700 nm) at ~2 µm pitch; single-photon avalanche diodes (SPADs) push sensitivity to photon-counting regimes. LiDAR ToF sensors achieve cm-level ranging at 100+ m. Hyperspectral imagers now fit in CubeSat form factors. Wafer-level packaging is compressing SWaP-C aggressively.
Competitive landscape
The primary competitive axes are spectral range, sensitivity floor, cost, and integration density. Silicon CMOS dominates cost-performance for visible; III-V (InGaAs, GaN, HgCdTe) owns IR but remains expensive and fab-constrained. Emerging alternatives include quantum-dot photodetectors, organic sensors, and graphene-based broadband devices.
| Approach | Spectral range | Cost/die | Integration |
|---|---|---|---|
| Si CMOS | 400–1000 nm | Low | Monolithic |
| InGaAs/III-V | 900–1700 nm | High | Hybrid flip-chip |
| Quantum dot | 300–2000 nm tunable | Dropping | Monolithic potential |
Companies using
Connected ideas
Sources
Frontier (open questions)
- To be added.