Image intensifier has the glass vacuum tube with the photocathode sensitivity 120-250 m A/lm. Light amplification of these image intensifiers is 120-900, resolving power in the center – 25-35 lines/mm. The particularity of these devices is the quality of image. The image is clear in the center only, with the distortion and low resolution in borders. Besides if in the field of view there are some light sources, e.g. torches, lamps or illuminated windows, they can spoil the image.
 
 

The fiber optic washer is mounted on the exit (sometimes on the enter) of the image intensifier instead of flat glass. It allows increasing considerably the resolving power of image intensifier and decreasing distortion of image form. Specifications - light amplification is about 1000, photocathode sensitivity - min. 280 m A/lm, resolving power in the center – 45 lines/mm.
 
 

Gen. II image intensifier of this generation differs from Gen. 1 by the presence of the microchannel plate (MCP). Light amplification is about 25000-50000, photocathode sensitivity - min. 240 m A/lm, resolving power in the center – 32-35 lines/mm. Image intensifier life is not less than 1000-3000 hours.
 
 

Gen. II+ image intensifiers have smaller size, the light amplification is about 25000-35000, but the photocathode sensitivity produces 600 m A/lm in the 450 to 950 manometer (near infrared) region of the spectrum, resolving power – 39-45 lines/mm. Image intensifier life is 1000-3000 hours.
 
 

Uses gallium-arsenide for the photocathode and microchannel plate for gain. The microchannel plate is also coated with an ion barrier film to increase tube life. Produces more than 800 m A/lm tn the 450 to 950 manometer (near infrared) region of the spectrum.