US 12713116 B2 / Aug 18, 2026

Measurement of a laser pulse repetition frequency using upconversion

A silicon-based image sensor can have i) a pixel array with one or more pixels and ii) an upconversion layer of crystals on at least one of a front side and a backside of the silicon-based image sensor. A pulse repetition frequency decoder cooperates with the upconversion layer of crystals to decode a pulse repetition frequency of a laser flash captured by one or more of the pixels of the silicon-based image sensor. The pulse repetition frequency decoder can use a known frame rate of the silicon-based image sensor and a decay time of an upconverting emission from the upconversion layer of crystals to decode the pulse repetition frequency of the laser flash.