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| Home / Laser Medicine / What is Laser/ Why we do not produce HeNe Lasers anymore |
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What is Laser - Why we do not produce HeNe Lasers anymore
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Why we do not produce HeNe Lasers anymore
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We started with the production of HeNe Lasers (with 2 mW) for acupuncture in 1980. At this time the laser tubes had a connection between the mirrors at the ends of the tube and the electrodes with an adhesive which was not really thight. As the He gas has the smallest atoms it diffuses very fast through all places which are not hermetically thight. So these tubes had a lifetime of only 2 to 4 years, also if they where not in use.
About two years later Siemens developed new tubes which had hermetically tight connections made of a special glass. Only these tubes have a lifetime of at least 20 years. So we used these tubes with 1.5 to 10 mW for many years.
At the same time there were pulsed infrared lasers on the market. The average output power of these lasers was lower than our output power, so there was a disadvantage and we did not produce this kind of lasers, but we watched the market.
About 1988 we got the first infrared laser diodes with 5 mW continuos output power and some competitors built lasers for acupuncture with these laser diodes. They had not much experience with the driving circuitry, so there were many defects. The advantage of these lasers was taht they where much smaller and lightweight and handsome in comparison with our 5 mW HeNe laser which had a handpiece with 40 mm diameter and which could be easily damaged if it dropped down because all HeNe lasers have glass tubes with a glass capillary inside which are not shockproof.
Then there followed the first laser diodes with visible light with 670 nm and 3 mW with a short lifetime, then with 5 mW and good lifetime. At this time we developed battery powered diode lasers with 25 mW infrared and with 5 mW red light. Some customers preferred the HeNe lasers because of our experience and because they had known about failures with laser diodes from competitors, but within one year nearly nobody wanted to buy the large HeNe lasers with the glass tube inside. So we stopped their production about 1992 as the last medical laser producer in Western Europe.
Since several years we produce battery operated diode lasers in accordance with CE rules with 660 nm with 12 mW to 200 mW and a 24 mW laser with 635 nm for users who want to have this wavelenght like the HeNe laser, but this 635 nm model does not withstand higher ambition temperatures like we have it in India, so we do not offer them in countries with higher temperatures.
The only advantage of the HeNe laser is the parallel laser output beam. Laser diodes have an elliptical output profile with a divergence of approx. 35 degrees to 12 degrees. So it is necessary to use an optic or a light conductor to get a point for acupuncture. We use a short piece of light conductor, and we can make a laser tip which is thin enough so that you can see where you penetrate, also e.g. inside the ear.
The point diameter of the light is 1.5 mm for the CL 12 and 3 mm for the CL 22 to CL 50 which is small enough also for acupuncture and save enough to meet all necessary standards and regulations for medical devices.
Prof. Dipl.Ing. Gerhard Silberbauer
Sept. 2, 2004
Vienna, Austria |
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