Coherent light generators – Particular pumping means – Electrical
Patent
1988-05-31
1989-06-06
Scott, Jr., Leon
Coherent light generators
Particular pumping means
Electrical
372 38, H01S 3097
Patent
active
048377899
DESCRIPTION:
BRIEF SUMMARY
DESCRIPTION
Technical Field
The present invention relates to a gas laser apparatus, more particularly relates to a high frequency discharge excitation laser apparatus.
BACKGROUND ART
In the prior art of this type of gas laser, for example, a carbon dioxide gas laser apparatus, a pair of metal electrodes are arranged at the two sides of a glass discharge tube of a predetermined length and a DC high voltage of, for example, 10 kV to 30 kV, is applied between said pair of metal electrodes via a predetermined series resistor (for setting the operating point in the discharge characteristics), thus imparting a predetermined energy to the carbon dioxide gas (in actuality, a mixture of N.sub.2 -He-CO.sub.2 is used) existing in the discharge tube. When the transition of the energy level of the gas molecules excited to the predetermined energy level in this way to a predetermined lower energy level occurs, laser light of a predetermined wavelength is generated. The laser light successively generated in this way travels back and forth between the reflecting mirrors provided at the two ends of the discharge tube for a predetermined laser oscillation. Note that the above-mentioned gas medium existing in the discharge tube is continually circulated through a circulation pump and coolant heat exchanger. Further, part is exhausted and replaced with fresh gas.
However, in a gas laser producing apparatus excited by DC high voltage, the gap length becomes longer due to the metal electrodes being disposed in the longitudinal direction of the glass discharge tube at the two ends thereof, requiring a high voltage, as mentioned above, and therefore making ensurement of insulation of the power source apparatus itself difficult. Further, along with this, the power source apparatus becomes large in size. Further, under said high voltage, the controllability for controlling the discharge voltage and discharge current to predetermined values required for stabilization of the laser output becomes poor and a high resistance series resistor is required for setting the discharge characteristics to a predetermined operating point, as mentioned above, whereby the loss due to power consumption increases, and further, consumption of the metal electrodes provided in the discharge tube and fouling of the discharge tube due to sputtering thereof, and other problems arise.
On the other hand, as a means to resolve the above problems, there has been proposed a gas laser producing apparatus of the so-called silent discharge excitation method, using an AC power source with a frequency of less than several hundred kilohertz, instead of the above-mentioned DC power source. In this case, a pair of electrodes are disposed at an interval of about several tens of millimeters, for example, in a predetermined gas under reduced pressure. A dielectric is placed inside each of the said electrodes and an AC voltage in the above-mentioned frequency range is applied between the electrodes. That is, specifically speaking, a ceramic tube is used for the dielectric. A pair of metal electrodes are disposed opposing each other on the outer surface of the ceramic tube along the longitudinal direction thereof. An AC voltage in the above-mentioned frequency range is applied between the pair of metal electrodes. Note that in the same way as the above-mentioned DC power source drive, reflecting mirrors are provided at the two ends of the ceramic tube (laser tube) and the gas medium in the laser tube (in the same way as the above, use if made of N.sub.2 -He-CO.sub.2 gas) is circulated.
In this case, the ions or electrons ionized in the gas medium move to the electrode side of the predetermined polarity and accumulate on the insulator provided on the inside thereof. Each time the polarity of the AC voltage changes, they move to the opposing electrode side. Current flows intermittently only when such changes in polarity occur. Therefore, the power injected into the gas medium per unit volume increases, when the applied voltage is constant, since the higher the frequenc
REFERENCES:
patent: 4375690 (1983-03-01), Tabata et al.
patent: 4510606 (1985-04-01), Yagi et al.
patent: 4618961 (1986-10-01), Sutter, Jr.
patent: 4706252 (1987-10-01), Egawa et al.
Fanuc Ltd.
Jr. Leon Scott
LandOfFree
High frequency discharge excitation laser apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with High frequency discharge excitation laser apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High frequency discharge excitation laser apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-45639