A laser diode，also known as an injection laser or diode laser, is a laser where the active medium is a semiconductor similar to that found in a light-emitting diode.Laser diodes are used in optical fiber systems, compact disc (CD) players, laser printers, remote-control devices, and intrusion detection systems.Laser diodes are numerically the most common type of laser, approximately 733 million diode lasers as compared to 131,000 of other types of lasers in 2004.
Laser diodes find wide use in telecommunication as easily modulated and easily coupled light sources for fiber optics communication. They are used in various measuring instruments, eg. rangefinders. Another common use is in barcode readers. Visible lasers, typically red but later also green, are common as laser pointers.
Medicine and especially Dentistry have found many new applications for diode lasers. The shrinking size of the units and their increasing user friendliness makes them very attractive to clinicians for minor soft tissue procedures. The 800nm - 980nm units have a high absorption rate for hemoglobin and thus make them ideal for soft tissue applications, where good hemostasis is necessary.
According to a case report published in the Nov. 15 edition of the Journal of the American Veterinary Medical Association, Jeannine Berger, DVM, Dipl. ACVB, and colleagues from the University of California, Davis, School of Veterinary Medicine wielded their trusty infrared diode laser 84 times in the left eye of a horse and 118 times in the right eye to solve his persistent headshaking problem. Headshaking can be caused by various physical abnormalities, such as light sensitivity, problems associated with the cranial nerves, tooth abnormalities, guttural pouch infections, ear mites, allergic rhinitis, and behavioral issues, among other triggers. Veterinarians and behaviorists have tried a plethora of ways to treat headshaking.
Over the course of a few months the patient, a 15-year-old Standardbred gelding used for competitive pleasure driving, developed episodes of side-to-side and up-and-down head flips and a slight head tilt. After an exhaustive physical examination and a battery of tests, cystic corpora nigra were found in both eyes. These are masses of modified iridal (iris) tissue attached at the border of the pupil. They are common in horses and usually do not cause visual problems.
In this case, however, the cystic corpora nigra in combination with a conditioned aversion to wearing blinkers was thought to be the most likely cause of this horse's headshaking.While anesthetized, the clinicians treated the gelding with the diode laser to deflate and coagulate the cysts. Afterward, they employed behavioral modification techniques to reintroduce the use of the blinkers so the gelding could return to his previous performance level. This goal was achieved within five months of diagnosing the problem and instituting treatment.
References:
http://www.thehorse.com
http://en.wikipedia.org/wiki/Laser_diode