In the absolute majority of structures is a laser emitter that generates short light pulses of high instantaneous power. Frequency of repetition or frequency modulation are selected so that the interval between two successive pulses was no less than the response time of detectable targets (which may be physically located further than a current range of the instrument). Selecting the wavelength depends on the function of the laser and the requirements for security and secrecy of the device, the most commonly used Nd: YAG-lasers and wavelengths (in nanometers):
1550 nm - infrared light invisible to any human eye, nor a typical night vision devices. The eye can not focus the waves on the surface of the retina, so traumatic threshold for waves in 1550 is significantly higher than for shorter wavelengths. However, the risk of eye injury in fact higher than that of visible light emitters - as the eye does not respond to infrared radiation, it does not work and a natural protective reflex Rights
1064 nm - near-infrared emission of neodymium and itterbievyh lasers, invisible to the eye but detectable night vision
532 nm - green emission of neodymium laser, effectively "piercing" the mass of water
355 nm - near ultraviolet radiation
In the short-range devices, instead of short pulses can be used continuous amplitude modulation of the radiation alternating voltage with frequency in units of megahertz.