To take up matter or energy. A large number indicates strong absorption. A noble gas used as an active medium in some lasers. An argon laser emits blue-green light.
Laser light is collimated because all of the rays are parallel to each other.
An electronic device that allows current to flow one direction but not the reverse direction. The ETD spectrum ranges from long wavelength radio waves and microwaves, through visible light, to the short wavelength, high energy ionizing radiation of X-rays and cosmic rays. Any radiation of energy by means of particles or electromagnetic waves. Thin, flexible devices used to carry light or other optical energy. The distance between the focusing lens and the point at which the smallest spot size of the light beam is achieved.