The human eye can detect light wavelengths from approximately 380 to 740 nanometers. This spectrum is also called the visible light. Wavelengths of light that are beyond the visible spectrum (visible light) are longer wavelengths and are called infrared wavelengths, or infrared light.
An infrared illuminator is simply said a flashlight that emits light in an infrared spectrum. It is invisible to the human eye, but visible for night vision devices.
IR illuminators are available in different wavelengths, which tells us also, in combination with what kind of night vision they are designed to be used.
Laser IR illuminators are the most powerful illuminators and are based on an infrared laser diode that produces the infrared light.
The name ´´Laser´´ stands for Light Amplification by Stimulated Emission Radiation.
The light out of a Laser is created when the electrons in atoms of special glasses or crystals absorb the energy from an electrical current.
The electrons then move from the lower-energy orbit to a higher-energy orbit around the atom´s core. When they get back to the normal state, they emit photons, which is the light that comes out of the laser emitter.
Laserluchs LA 850-50-PRO II
The light out of a laser infrared illuminator is ´´coherent´´, which means that the wavelength is very narrow and all emitted photons have the same wavelength.
An LED for comparison, emits light in a much wider spectrum, so an LED infrared illuminator with specified 850nm wavelength emits light from approximately 825nm up to 875nm.
The emitted light out of an infrared laser illuminator is also very focused with a sharp edge on the side.
On illuminators with an adjustable beam, the light can be focused to a very small dot, which offers the user extreme distance observations.
For example, an 900nm IR laser can be only used for Gen. 3 night vision devices or digital night vision devices, because they detect higher wavelengths. An LED infrared light with the same wavelength could be also used for Gen. 2 analog night vision devices because of the wider wavelength spectrum.
When buying an infrared illuminator, you have to be cautious what is the maximal wavelength your night vision can detect. If the emitted light of your infrared illuminator is beyond the spectrum, it is invisible for such a device.
For Gen. 1 NV devices we would recommend an IR illuminator with a wavelength between 750nm and 780nm,
For Gen. 2 an illuminator with a wavelength of 850nm, or even higher (up to 900nm) if you own a high-quality IIT in your device.
For Gen. 3 an IR illuminator is mostly not needed, but one with a wavelength of 850nm - 900nm would work perfectly
Night vision optics are mostly used for hunting purposes. Because of that, the manufacturers developed many types of mounting solutions for their IR illuminators.
The most common are IR illuminators with a 30mm main tube, so a normal rifle scope mounting ring can be used. This one can be then attached to the optic itself, or directly on the rifle. The most common mounting solutions on NV optics are short 11-millimeter dovetail rails or short Picatinny rails.
For mounting on the rifle, it is the easiest way to use a mounting ring for a Picatinny rail. Thanks to that, it can be mounted anywhere on the rail.
If you don´t have a Picatinny rail mounting solution on your rifle, then a clamp-mount can be used. This can be clamped directly on your rifle scope or the rifle barrel.
A short presentation of Laser IR illuminators is available here.