Nanolasers are devices that emit electromagnetic radiation using light amplification by stimulated emission of radiation in the wavelength range from ۱۸۰ nm to ۱ mm

Note: The intensity of the incoming electromagnetic wave decreases as it passes through the absorption process between the material. Absorption is caused by the conversion of part of the light energy into the specific motion and oscillations of the absorbing material.

The ability of a medium to absorb electromagnetic beams depends on several factors, including the electronic structure of atoms and molecules, the wavelength of the beam, the thickness of the absorber layer, and internal factors such as temperature and concentration of the absorber material. The absorption coefficient is denoted by µa and is defined by the probability of absorption of a light photon when traveling in a very small length component of its path and is in units of 1-mm, which indicates the amount of reduction in radiant energy due to absorption of rays per unit length z.

Nanolasers are devices that emit electromagnetic radiation using light amplification by stimulated emission of radiation in the wavelength range from 180 nm to 1 mm.  The electromagnetic spectrum of nanolasers includes energy from gamma rays to electricity.   Nanolaser radiation for current military and commercial applications includes ultraviolet, visible, and infrared radiation of the spectrum.  The ultraviolet radiation for nanolasers consists of wavelengths from 180 to 400 nm.  The visible region consists of radiation with wavelengths between 400 and 700 nm.  This is the part we call visible light.  The infrared region of the spectrum consists of radiation with wavelengths between 700 nm and 1 mm.  Nanolaser radiation absorbed by the skin penetrates only a few layers.  In the eye, visible and near-infrared radiation passes through the cornea and is focused and absorbed by the retina.  It is the wavelength of light that determines the visible sensation of color: violet at 400 nm, red at 700 nm, and the other colors of the visible spectrum in between.  When radiation is absorbed,  the effect on the absorbing biological tissue is photochemical, thermal, or mechanical: in the ultraviolet region, the action is mainly photochemical.  In the infrared region, the action is thermal.

Conclusion :

The intensity of an incoming electromagnetic wave is reduced as it passes through a material through the process of absorption. Absorption results from the conversion of a portion of the light energy into the specific motion and oscillations of the absorbing material.