Optical sensor element, thermal image sensor and method of detecting thermal radiation

Abstract

An optical sensor element for sensing thermal radiation comprises a light emitter having a cavity, the light emitter being configured to emit coherent electromagnetic radiation through an emission surface and to undergo self-mixing interference, SMI, caused by reflected electromagnetic radiation reinjected into the cavity. A micro-opto-mechanical transducer is arranged distant from the emission surface, the transducer being configured to undergo mechanical deflection according to thermal radiation absorbed by the transducer, and to reflect the electromagnetic radiation emitted by the light emitter back into the cavity for generating the SMI. A detection unit is configured to detect a degree of the generated SMI, determine from the detected degree a deflection of the transducer, and generate an output signal indicating the determined

Dependencies are inferred from the claim text.