An invention concerning the electrode structure of a gas laser device is disclosed. In the outer peripheral part of a discharge gas circulating hole (32) provided in the central part of an upper gas stream side one (16) of electrodes (14) and (16) disposed at both the ends of a discharge tube (8), a plurality of gas circulating apertures (34) are further provided over the entire periphery. A glow discharge portion in the discharge tube (8) is fined towards the central part of the tube by a gas which passes through the outer-peripheral gas circulating apertures (34). Thus, the laser intensity profile becomes the Gaussian distribution, and the laser generation efficiency is enhanced.
A gas laser has an electrode of improved construction. The electrode, for example a cathode, comprises an inner cathode and at least an outer cathode spaced from the inner cathode and disposed on the side thereof away from to an anode. Each of the cathodes has a central hole from which glow discharge is formed, and the outer cathode further has a plurality of through-holes around the central hole. A gas medium flowing in a discharge tube passes through the central hole of the inner cathode via the central hole and through-holes of the outer cathode. The gas medium forcedly enters the glow discharge from the inner cathode thereby to cause it expand and a part of the gas medium having passed through the through-holes of the outer cathode squeeze the glow discharge from the outer cathode so that the glow discharge can enter the glow discharge from the inner cathode. Therefore, the current density of the glow discharge in the discharge tube is made information.
A low pressure gas electrode utilizing ionized gas in a glow discharge regime forms a transparent electrode for electro-optical switches. The transparent electrode comprises a low pressure gas region on both sides of the crystal. When the gas is ionized, e.g., by a glow discharge in the low pressure gas, the plasma formed is a good conductor. The gas electrode acts as a highly uniform conducting electrode. Since the plasma is transparent to a high energy laser beam passing through the crystal, the electrode is a transparent electrode. A crystal exposed from two sides to such a plasma can be charged up uniformly to any desired voltage. The plasma can be created either by the main high voltage pulser used to charge up the crystal or by auxiliary discharges or external sources of ionization. A typical configuration utilizes 10 torr argon in the discharge region adjacent to each crystal face.
A gas laser arrangement includes a discharge tube between a cathode and an anode, the discharge tube including a central discharge channel and at least one gas return channel. A blocking electrode is provided at the openings of the gas return channels at least in the cathode space and possibly also in the anode space, the blocking electrode being connected to a blocking voltage to avoid misfirings of the laser through the gas return channels.
