Laser Therapy (also known as photobiomodulation, low-level laser therapy, cold laser therapy, and laser biostimulation) is an emerging medical and veterinary technique in which exposure to low-level laser light can stimulate or inhibit cellular function leading to beneficial clinical effects. Laser therapy is any treatment using intense beams of light to precisely cut, burn, or destroy tissue. The term laser is an acronym for “light amplification by stimulated emission of radiation.”

The laser is used for many medical purposes. Because the laser beam is so small and precise, it enables doctors to safely treat tissue without injuring the surrounding area. Lasers may be used to remove growths or cauterize blood vessels. They may also be used during eye surgery. Clinical applications include treating soft tissue injury, chronic pain, wound healing and nerve regeneration, and possibly even resolving viral and bacterial infections. A promising clinical application is the treatment of inflammation, where the anti- inflammatory effect of location-and-dose-specific laser irradiation produces similar outcomes as NSAIDs, but without potentially harmful side-effects.

Laser surgery uses a laser light source to remove diseased tissues or treat bleeding blood vessels. The laser may also be used for cosmetic purposes, including removal of wrinkles, tattoos, or birthmarks.

Laser surgery can be used, for example, to:
Remove tumors (brain, liver)
With minimal damage to surrounding healthy tissue
With minimal scarring
Seal small blood vessels to reduce blood loss
Seal lymph vessels to reduce swelling and decrease the spread of tumor cells
Seal nerve endings to reduce postoperative pain
Remove warts, moles, and tattoos
Reduce the appearance of skin wrinkles, scars, and other skin blemishes
Remove hair

As with any type of surgery, laser surgery is not without risks. Possible problems include incomplete treatment of the problem, pain, infection, bleeding, scarring, and skin color changes. Some laser surgery is performed under general anesthesia.

A laser is a light beam that can be precisely focused. It is used to treat tissues by heating the targeted cells until they “burst.” There are several types of lasers, including the carbon dioxide (CO2) laser, the YAG (yttrium aluminum garnet) laser, and the pulsed dye laser. Each laser has specific uses. The color of the light beam used is directly related to the type of surgery being performed and the color of the tissue being treated.

The combination of wavelength, intensity, duration and treatment interval is complex with different diseases, injuries and dysfunctions needing different parameters and techniques. Certain wavelengths of light at certain intensities will aid tissue regeneration, resolve inflammation, relieve pain and boost the immune system. It is thought that the mechanism is photochemical rather than heat-related. Observed biological and physiological effects include changes in cell membrane permeability, regulation of adenosine triphosphate and nitric oxide.

Variable factors include: effective wavelength, dose, dose-rate effects, beam penetration, coherence and pulses (peak power and repetition rates). Laser average power is typically in the range of 1-500 mW; some high peak power, short pulse width devices are in the range of 1-100 W with typically 200 ns pulse widths. The average beam irradiance then is typically 10 mW/cm2 - 5 W/cm2. The wavelength is typically in the range 600-1000 nm but some products are available outside this range.

Laser Therapy

June 18, 2003… STOCKHOLM, Sweden
Comlase has introduced a novel passivation and facet coating reactor that utilizes the company’s proprietary Native Nitride Ion Beam Epitaxy (N2IBE) process to increase damage threshold, improve output power and extend lifetime of edge emitting semiconductor lasers. The N2IBE process utilizes nitrogen bombardment to eliminate surface oxides and impurities and nitridize any reactive chemical bonds within the device material, thus preventing oxidation during facet coating and subsequent operation. The result is a substantial increase in catastrophic optical mirror damage (COMD) threshold and laser reliability.

The N2IBE process is useful for a wide range of III-V semiconductor materials, including AlGaAs, GaAs, GaN, InGaN, InP, AlInGaAs, InGaP, InGaAsP, operating anywhere over the 400 nm to 1700 nm wavelength range.

The reactor itself consists of a load locked, stainless steel, ultra-high vacuum (10-9 Torr) chamber containing an ion gun for facet milling and passivation, and two electron-beam guns and effusion cells for producing antireflection (e.g. alumina) and high reflection (e.g. alumina/silicon) coatings. This construction allows all operations to be completed within a single run, and eliminates the need to break vacuum at any time during the process.

The system is nominally configured to work with 10 mm wide semiconductor laser bars, which have been cleaved in air, rather than under vacuum conditions. Batch sizes of 200 bars, together with short cycle time, make the system very compatible with high volume production environments.

Novel Facet Passivation Reactor Enables Higher Power Semiconductor Laser