Evolution of Image Intensifiers | Nikon 9350 instruction

1.5Evolution of Image Intensifiers

The image intensifier tube has evolved substantially over the past few decades. This evolution is described by different generations (“Gen”) of technology as follows:

Gen 1 – These are the first so-called night-vision devices and were introduced in the early 1960s and first fielded in Vietnam. These devices utilized a multi-alkali S-25 photocathode having a spectral response extending from visible to about 850nm. In order to have sufficient sensitivity for use in night vision applications, three Gen 1 image intensifier tubes needed to be cascaded, each producing some gain. The result, though highly sensitive, suffered from significant edge distortion as well as poor life expectancy (less than 1000 hours).

Gen 2 – By the 1970s, the microchannel plate was introduced that delivered high sensitivity imaging without the need to cascade three stages. As a result, night vision pocketscopes and night vision goggles emerged as viable products with improved operation life (2000-4000 hours).

Gen 2+ – More recently, improved Gen 2 devices have been developed (known as "SuperGen") that deliver improved sensitivity and improved lifetime (10,000 hours).

Gen 3 – By the early 1990s, image intensifiers became available with photocathodes made from gallium arsenide. This produced significantly more sensitivity and an extended near-infrared spectral responsivity range to 950nm.

Gen 3 Thin Film –Introduced in 2002, thin film image intensifiers incorporate a new manufacturing technique, which have made it possible to increase further the unit's sensitivity, improve signal-to- noise and contrast performance and reduce blooming due to viewing bright sources.

1.6Benefits of AstroScope Night Vision

The AstroScope Night Vision System is a modular system incorporating a “common module” approach in which the image intensifier is integrated into an assembly consisting of a front lens adapter and a back body adapter. The AstroScope System delivers several important benefits over other night vision systems. These include:

•Optimized Performance: Because of the modular design and the accessibility to the image intensifier, optical adapters and interfaces can be designed so that each configuration delivers optimized performance. This is due to the accessibility to the photo cathode as well as the phosphor image output.

•Seamless Integration into Daylight Imaging Systems: The AstroScope’s component interfaces are both electrical (where electrical contacts connect components) and mechanical. This results in a seamless integration with daylight imaging systems. As

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