Image Intensifier Tubes

Image Intensifier Tube Selection Guide

An image intensifier tube is the core of an analog night vision device. It turns the faint light of a night scene into electrons, multiplies them thousands of times and converts them back into a bright visible image. JOVSTAR makes five proximity-focused tube series with S25+ (Gen2+ class) extended-red-response photocathodes, each available in three performance classes from FOM 1400 to FOM 1800, for OEM night vision monoculars, goggles, binoculars and scopes.

Choose the performance class first: Class C for standard enhancement at the lowest power, Class B for auto-gated operation across changing light, and Class A for the highest sensitivity and gain. Then choose the tube series that fits your optical design, for example a non-inverting output window when your optics erect the image.

All five series share the Class C / B / A electrical and imaging specifications shown in Core Specifications above. Contact JOVSTAR for output window options and mechanical drawings for your design.

How an Image Intensifier Tube Works

An image intensifier tube amplifies light electronically in three stages inside a vacuum envelope.

Photocathode

Light from the objective lens falls on the photocathode, which releases electrons in proportion to the light. JOVSTAR tubes use S25+ multi-alkali photocathodes with extended red response, so they also use the near-infrared light that is plentiful in the night sky. Sensitivity is 700 μA/lm on Class C, 800 μA/lm on Class B and 1000 μA/lm on Class A (2856K source), over a 17.5 mm effective cathode diameter.

Microchannel plate

The electrons enter a microchannel plate (MCP), a thin disc with millions of tiny channels. Each electron hits the channel walls and releases more electrons, multiplying the signal. This gives JOVSTAR tubes a luminance gain of 8,000–12,000 cd/m²/lx on Classes C and B, and 10,000–20,000 on Class A.

Phosphor screen

The multiplied electrons strike a phosphor screen that glows to form the visible image. JOVSTAR tubes use P43 green phosphor. Because the tube is proximity-focused, with the photocathode, MCP and screen very close together, it has no electron lens: the image is not distorted and magnification is 1×.

Class C vs Class B vs Class A

The three classes share the same tube structure and differ in sensitivity, noise, resolution and power supply.

• Class C: FOM 1400, SNR 23, 60 lp/mm, a normal power supply and the lowest power consumption at 33–51 mW. A cost-effective choice for general observation.
• Class B: FOM 1600, SNR 25, 64 lp/mm, with an auto-gating power supply that keeps 54 lp/mm resolution at 200 lx and protects the tube under bright light. 55–85 mW.
• Class A: FOM 1800, SNR 28, 68 lp/mm, auto-gating, and the highest gain (10,000–20,000 cd/m²/lx) and output brightness (4–10 cd/m²). The best choice for the darkest conditions.

For the full parameter list by class, see Core Specifications above.

What Determines Image Intensifier Performance

Three numbers do most of the work when comparing tubes: resolution, signal-to-noise ratio and figure of merit.

• Resolution (lp/mm). How fine a detail the tube can show, measured in line pairs per millimeter: 60, 64 and 68 lp/mm for Classes C, B and A.
• Signal-to-noise ratio (SNR). How clean the image stays in very low light. SNR matters most in the darkest conditions, where noise makes the image look like moving “snow”.
• Figure of merit (FOM). Resolution multiplied by SNR, used as a single overall measure: 1400, 1600 and 1800 for Classes C, B and A.
• Auto-gating. An auto-gated power supply switches the photocathode voltage on and off very rapidly as light increases. It keeps the image usable when lights, headlights or dawn appear, and protects the tube. JOVSTAR Class B and Class A tubes are auto-gated and operate from 1×10⁻⁶ lx.

To choose, match the class to the darkest conditions your users will face and to the power budget of the device: Class C draws 15 mA, Classes B and A 25 mA.

Integrating an Image Intensifier Tube: Power, Size and Optics

JOVSTAR tubes are compact and low-power, with built-in strong-light protection and polarity-reversal protection.

The 2.2–3.4 V input lets a device run directly from a single 3 V CR123A cell. The output window must match the optics: an objective lens forms an inverted image, so a non-inverting tube such as the JV-IT1D or JV-IT20 is used with optics that erect the image, for example in binocular and scope systems. Weight is 80 g per tube (98 g for the JV-IT1D).

Image Intensifier Tube Applications

JOVSTAR image intensifier tubes are built into four main kinds of devices.

Night vision monoculars

Single-tube monoculars are the most common use, handheld or helmet-mounted. JOVSTAR’s own JV-NVM201 uses a Gen2+ tube with FOM 1400–2200 and runs 60–100 hours on one CR123A.

Binocular and panoramic goggles

Two-tube goggles give natural depth perception; four-tube goggles such as the JV-NVF201 widen the view to ≥100° horizontal.

Night vision scopes

Magnified scopes such as the JV-NSR201 (3.8×) use a tube behind a long-focal-length objective for observation at distance.

Fusion devices

In fusion goggles such as the JV-FNV2105, the intensified image is combined with a thermal image. See our night vision goggles guide for complete devices.

OEM and ODM Image Intensifier Tube Projects

JOVSTAR supplies image intensifier tubes to night vision device manufacturers, with support for performance class selection, output window and mechanical requirements, and integration into monoculars, goggles, binoculars and scopes, from samples and prototyping to batch delivery.

Learn more about OEM & ODM customization, our factory and testing capabilities and R&D laboratories. ISO, CE and FCC certifications are shown on our About page.

Last updated: October 28, 2026 · Reviewed by JOVSTAR R&D Engineering Team