Dual-spectrum photocathode for image intensification

A dual-spectrum image intensifier fabrication method comprising:

• depositing a first optoelectronic material on a first surface of a photocathode substrate disposed transverse to an optical axis of the dual-spectrum image intensifier such that at least a portion of incident photons pass through the photocathode substrate and the first optoelectronic material, the first optoelectronic material to generate photo-electrons responsive to incident photons in a first spectral band;
• depositing a second optoelectronic material on a surface such that at least a portion of the incoming photons pass through the second optoelectronic material, the second optoelectronic material to generate photo-electrons responsive to incident photons in a second spectral band, the second spectral band different from the first spectral band the second optoelectronic material disposed on the same side of the substrate as the first photodetector array;
• depositing an electron multiplier along the optical axis of the dual-spectrum image intensifier the electron multiplier spaced apart from the photocathode substrate;
• and
• reducing absolute pressure in the space between the dual-spectrum image intensifier the electron multiplier to less than atmospheric pressure.

An enhanced vision system, comprising:

• an objective lens array;
• dual-spectrum image intensifier comprising:
• a photocathode that includes:
• a first photodetector array that includes a first optoelectronic material disposed on a substrate to generate photo-electrons in response to incident photons in a first spectral band;
• and
• a second photodetector array that includes a second optoelectronic material to generate photo-electrons in response to incident photons in a second spectral band, the second spectral band different from the first spectral band, the second photodetector array disposed on a same side of the substrate as the first photodetector array;
• wherein the photo-electrons generated by both the first photodetector array and the second photodetector array are emitted into a first vacuum space adjacent to at least a portion of the second photodetector array;
• and
• a microchannel plate to generate secondary electrons, the microchannel plate separated from the photocathode by the first vacuum space;
• wherein the secondary electrons generated by the microchannel plate are emitted into a second vacuum space adjacent to the microchannel plate;
• a phosphor screen to generate photons corresponding to an enhanced image responsive to incident secondary electrons, the phosphor screen separated from the microchannel plate by the second vacuum space;
• and
• an eyepiece lens array.