Laser detection using multiple image sensors

An apparatus, comprising:

• a first silicon-based image sensor that has an upconversion layer of crystals on the first silicon-based image sensor configured to receive light from a common beam splitter with a second image sensor, wherein the second image sensor are configured to receive light from the common beam splitter in a first range of wavelengths,
• a dichromatic coating on the common beam splitter configured to pass some of the light in to be incident on the upconversion layer of crystals in a second range of wavelengths, which will be absorbed and converted by the upconversion layer of crystals into a third range of wavelengths and then transmitted to pixels in the first silicon-based image sensor, and
• a pulse repetition frequency decoder configured to cooperate with the upconversion layer of crystals to decode a pulse repetition frequency of a laser flash in the second range of wavelengths passed by the dichromatic coating on the common beam splitter and subsequently upconverted and then captured by one or more pixels of the first silicon-based image sensor.

A method to decode a pulse repetition frequency of a laser flash, comprising:

• providing a first silicon-based image sensor with an upconversion layer of crystals on the first silicon-based image sensor to receive light from a common beam splitter with a second image sensor, wherein the second image sensor is configured to receive light from the common beam splitter in a first range of wavelengths,
• providing an optical band pass filter to pass some of the light to be incident on the upconversion layer of crystals in a second range of wavelengths, which will be absorbed and converted by the upconversion layer of crystals into a third range of wavelengths and then transmitted onto pixels in the first silicon-based image sensor, and
• providing a pulse repetition frequency decoder to cooperate with the upconversion layer of crystals to decode the pulse repetition frequency of the laser flash in the second range of wavelengths passed by the optical band pass filter and subsequently upconverted by the upconversion layer of crystals into the third range of wavelengths and then captured by one or more pixels of the first silicon-based image sensor.

A method to decode a pulse repetition frequency of a laser flash, comprising:

• providing a first silicon-based image sensor with an upconversion layer of crystals to receive light from a common beam splitter with a second image sensor, wherein pixels in the second image sensor are configured to receive light in an image frame from the common beam splitter in a first range of wavelengths,
• providing a dichromatic coating on the common beam splitter to pass some of the light to be incident on the upconversion layer of crystals in a second range of wavelengths, which will be absorbed and converted by the upconversion layer of crystals into a third range of wavelengths and then transmitted to one or more pixels in the first silicon-based image sensor, and
• providing a pulse repetition frequency decoder to cooperate with the upconversion layer of crystals to decode a pulse repetition frequency of a laser flash in the second range of wavelengths passed by the dichromatic coating on the common beam splitter and subsequently upconverted by the upconversion layer of crystals into the third range of wavelengths and then captured by one or more pixels of the first silicon-based image sensor.