Diode lasers are used to produce low level energy laser for different types of purposes. If you have used a laser pointer before for a business presentation, then you have had a close encounter with a diode laser. These are also used in different fields such as medicine where they use it for dental whitening and skin lightening. They are also used in medical equipment, industrial equipment and in home electronics. Surely people from around the globe even those living in cities like Columbus, Ohio have been privileged to use this technology.
History of laser diodes
Robert and his team at the General Electric research center in 1962 are widely accepted to be the first to have demonstrated coherent light emission from a semiconductor diode and this became the first laser diode. Later that same year, Nick Holonvak Jr. demonstrated the first visible wavelength laser diode. There were also other teams who were recognized for their participation and they too were able to receive credit for the historic initial demonstrations of efficient light emission and lasing in semiconductor diodes in 1962 and also after that. These teams consist of IBM, Texas Instruments, MIT Lincoln Laboratory and RCA Laboratories. In 1963, the Soviet Union team led by Nicolav Basov was able to produce gallium arsenide laser of GaAs lasers.
The first type of laser diodes to be produced was homojunction diodes. Heterostructures are known to have layers of semiconductor crystals with differing bandgap and reflexive index. While working at RCA laboratories in the mid 1950s, Herbert Kroemer was able to distinguish heterojunctions formed from heterostructures as having special advantages for varying types of electronic and optoelectronic devices including diode lasers. Afterward, LPE pushed through the technology of making heterojunction diode lasers.
Single-heterojunction lasers were the first heterojunction diode lasers. These lasers used aluminum gallium arsenide. The problem with this set-up was that diode laser did not function well in continuous wave operation when in room temperature. The room temperature issue was later met with an innovation in the form of double heterostructure laser. This technology may have been man’s first attempt at nanotechnology. The first laser diode to attain continuous wavelength was the double heterostructure demonstrated by Zhores Alferov and partners including Dmitri Z. Garbuzov of the Soviet Union and Izuo Hayashi and Morton Panish who work for the United States but it was accepted that Zhores Alferov and his team were the ones who made it work first. Both Alferov and Kroemer got the 2000 Nobel Prize in Physics for their accomplishments.
How does diode laser work?
Diode Lasers utilize microscopic chips of gallium or other semiconductors in order to generate light within a compact package. The laser ray is produce by the energy variance between electrons in the semiconductors. Common diode lasers known to us are the ones used in electronic devices and pointers that have a maximum output of three and five megawatts of optical power. There are three primary types of laser diodes that are commonly used and these are homojunction, heterojunction and pulsed laser diodes. Diode lasers are typically sensitive and limited amount of energy must be used to prevent burning out. Care should be given in order to avoid damaging its construction.
Laser diodes are known to generate a lot of heat. As a precautionary measure, they need heat sinks. Heat sinks are designed to transfer heat on fluids. The diode is therefore connected to the heat sink through a thermally conductive connection plate. The heat from the diode will be transferred to the connection plate and goes to the heat sink. The heat can either leave from the side of the diode or the heat can be directed to the bottom of the diode.
Lenses formed from specialized objects act as a driving focus for laser diodes constructed to direct light in the right direction. These lenses can be adjusted in order for the light to be quickly altered thereby changing the intensity of the width of the light which is more appropriate for control. Drivers are also attached to the diodes in order to control the laser. There are drivers the permits the user to chose between a constant diode current or a current that can be managed by the user. There exist diodes that can adjust to the slight changes of the environment for a more quality beam of light. Drivers allow the user to use diode from its minimum power level to its maximum power level.
Diode Lasers are also used in dentistry applications
One of the most popular practical applications of diode lasers can be seen in the dentistry market. Diode laser can be very flexible and it is used in different procedures. Now, it can be used to perform soft-tissue surgery including cases that involve removing tumors and making lesions to the soft tissues of the mouth. Diode lasers have the capacity to kill common germs and bacteria hence they are also used to sterilize areas of the mouth before doing procedures like root canals, cavity treatment and the like.
Dentists use diode laser for plaque removal and laser tooth cleaning. Heavily calcified deposits can be removed and this leaves the mouth free of cavity-causing plaque.
There are some warnings issued with the use of diode laser
In 1997, the FDA issued warnings against the potential danger with the use of handheld laser pointers. There have been reports of eye injuries involving children caused by laser pointers and toys hence the Academy of Ophthalmology also issued its warnings in 1998 indicating that children should refrain from using diode lasers. Since the laser’s wavelengths are not similar, there is no telling of the damage that it could cause. Although diodes at a distance of ten feet cannot pose immediate danger, near infrared wavelengths can be absorbed by the retina and this could lead to a lasting ocular injury.
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