noun
- Plural of photocathode; electrodes that emit electrons when struck by photons of light, used in photoelectric devices and imaging tubes.
Usage: technical; physics
Examples
- The photomultiplier tube contains photocathodes that convert incoming light into electrical signals.
- Modern night-vision devices rely on sensitive photocathodes to detect faint light.
- The researchers tested different materials for photocathodes to improve quantum efficiency.
- Photocathodes in image intensifiers amplify weak optical signals for surveillance applications.
- The vacuum tube's photocathodes were coated with a special alkali metal compound.