57. Laser and its biophysical effects

yaboiemil's version from 2016-02-02 11:48


1. Lasers are the only artificial source of coherent light.
2. Laser is the acronym for Light Amplification by Stimulated Emission of Radiation.
3. Lasers are Coherent and Monochromatic.
4. The principle behind lasers is the alternation of excitation and de-excitation, which
releases photons of energy. The Active medium is excited by the Excitation Energy
Source (Optical Pumping). A photon of a specified wavelength is then shot at the
excited electrons, causing them to release a photon and move to a lower excitation energy.
5. The active medium is the medium which is excited within a laser. This may include
Ruby,or a solution of organic dyes or a mixture of helium and neon.
6. The state of the active medium determines what kind of laser it will be. For example
Solid/Liquid/Gas/Plasma/Free electron
7. The Photons released from the de-excitation are then amplified by an optical resonator.
This will amplify the resulting photons with the same energy, to produce a coherent,
monochromatic beam.
8. Lasers can be CONTINUAL or IMPULSE
9. The Optical Resonator amplifies coherent radiation by reflection from mirrors.
10. Low Pulse Lasers are used in physiotherapy, as they have biostimulation properties.
They influence the electric potential in cell membranes, and increase the activity of
enzymes, damaging the chemical structures and speeds up DNA synthesis.
11. High power Lasers have thermal effects. They can be used in surgery as laser scalpels.