Laser energy is absorbed by a coloured substance (chromophore) e.g. blood (haemoglobin), melanin (in the skin & hair). Laser energy is also absorbed by water in the skin.
Properties of Laser Light:
- Monochromatic: Which means laser light has a single colour and a single wavelength. This property allows us to choose a specific laser for specific purposes. The wavelength of a light determines the effect on the tissue.
- Parallel (collimated): All the light rays in a laser beam are parallel to each other.
- Coherent: Light waves in a laser are always in co ordination with each other.