Compact proximity focused image sensor

A vacuum proximity focused image sensor comprising:

• a photocathode window assembly having a face with one or more raised features and a photocathode layer;
• an anode assembly comprising a silicon substrate having an electron sensitive surface;
• a malleable metal seal bonding the photocathode window assembly and the silicon substrate to each other, forming a vacuum gap that separates the photocathode layer of the photocathode window assembly and the electron sensitive surface of the silicon substrate of the anode assembly by a gap height defined by the one or more raised features of the face of the photocathode window assembly;
• a first electrical connection to the photocathode layer, for a voltage bias;
• and
• a second electrical connection to the electron sensitive surface, for the voltage bias;
• wherein the malleable metal seal is formed such that a first end of the first electrical connection is at the photocathode layer, a second end of the first electrical connection is outside the vacuum gap, a first end of the second electrical connection is at the electron sensitive surface, and a second end of the second electrical connection is outside the vacuum gap.