1. Field of the Invention
The present invention relates to laser oscillation apparatus. More particularly, this invention relates to new laser oscillator devices adaptable for use as laser-machining discharge excitation type laser oscillators which require large-output and high-efficiency laser light.
2. Description of the Related Art
Typically, in a discharge laser oscillation apparatus, the discharge is performed with respect to a laser medium in order to attain laser oscillation. When this is done, the laser medium increases in temperature. The higher the medium temperature, the less the efficiency of such laser oscillation. This phenomenon will become more severe especially in pulse laser oscillation devices.
Conventionally, in order to avoid such reduction of laser oscillation efficiency due to temperature increase of the laser medium thereby obtaining efficiency-enhanced laser oscillation, one approach is to wait for the laser medium to have lowered its temperature down to an acceptable level; another approach is to replace and cool the laser medium per se.
Additionally, in large-output lasers such as an excimer laser or carbon dioxide gas laser or the like, a convection device such as a fan blower or the like as well as a thermal exchanging machine are provided inside of a laser tube for forcibly causing a laser medium gas to exhibit convection to thereby achieve cooling by substitution and circulation from a laser cavity or between electrodes, which in turn lets the resulting laser output power stay higher.
However, in the prior art, large-output fan blower devices have been required in order to attain the circulation or percolation of the laser medium such as a gas or the like within laser devices or laser tubes, which fan blowers might be configured from large-scale complicated electrical equipment including a motor, fan, vacuum shaft coupler and others, resulting in an increase in the size and production cost of the laser devices and laser tubes concerned. Another problem faced in the prior art is that resultant power dissipation can significantly increase undesirably.