The cold laser produces an impulse of light at a specific wavelength (usually 600 to 980nm) that minimizes reflection and scattering but maximized absorption of the the energy (in photons) at a desired depth.
Some conditions like joint pain require a deep penetration (4-5 inches) that can only be achieved using a powerful laser emitter. Many systems also have other lower wavelengths and lower-power emitters for treating shallow tissue (like the lymphatic system or surface scars). For shallow treatments, light emitting diodes (or LEDs) with a shorter wavelength (600 to 700nm) are more cost effective for adding photons to the shallower tissue. In addition, red light diodes with a wavelength of 630 to 680 nm may be used to add energy to even shallower levels of tissues. It is the general consensus that wavelengths below 660 nanometers are very easily absorbed in the surface tissue and are not optimized for deep tissue healing.
The goal of laser therapy is to deliver light energy units from red and infrared laser radiation, called photons, to damaged cells. It is the consensus of experts is that photons absorbed by the cells through laser therapy stimulate the mitochondria to accelerate production of ATP. This biochemical increase in cell energy is used to transform live cells from a state of illness to a stable, healthy state.
Over 4000 studies have been conducted in recent years to validate the effectiveness of cold laser therapy. Cold lasers treatment systems may be cleared by the FDA.