Physics / mechanism
Microbolometers are uncooled thermal infrared detectors. Incident LWIR photons (8–14 µm) heat a thermally isolated membrane—typically vanadium oxide (VOx) or amorphous silicon (a-Si)—whose resistance changes measurably with temperature (TCR: −2 to −3 %/K for VOx). A ROIC (readout integrated circuit) samples each pixel’s resistance change; no photon-to-electron conversion occurs, so no cooling is required. Arrays are monolithically integrated via MEMS post-processing on standard CMOS ROICs. Current SoA: 12 µm pixel pitch, 1920×1080 formats, NETD <30 mK, f/1.0. Key suppliers: FLIR/Teledyne, Lynred, BAE Systems, INO, Seek Thermal, Hikvision.
Competitive landscape
Cooled photon detectors (InSb, HgCdTe/MCT) deliver NETD <10 mK and higher frame rates but require Stirling or Peltier cooling, adding cost, weight, and MTTR risk—dominant in military targeting, astronomy. Quantum well infrared photodetectors (QWIPs) occupy a middle ground. For MWIR (3–5 µm), InAsSb detectors outperform microbolometers on sensitivity but not on SWaP-C. Graphene and 2D-material bolometers are pre-commercial. Pyroelectric detectors (LiTaO₃) are lower-cost but pixel-limited.
Companies using
Connected ideas
Sources
Frontier (open questions)
- To be added.