| 摘要 |
<p>The main purpose of this invention is to stabilize the output power of a laser. In order to accomplish this purpose, the amount of the laser gas supplied to a laser chamber (4) is controlled while the voltage of a power source (17) is maintained at a fixed value or within a fixed range so that the output power (E) of the laser beam (La) can be a target value when the output power (E) is detected deviating from the target value. The second purpose of this invention is to prevent the drop of the output power (E) by reducing the consumption of preionizing electrode. This purpose is accomplished as follows. A secondary capacitor (C2) is charged with a pulse current discharged from a primary capacitor (C1) and boosted through a pulse transformer (20). When the capacitor (C2) is charged, a magnetic switch (SR) connected to the capacitor (C2) is saturated and conductive, and the current passes through the preionizing electrode (6) connected in series with the switch (SR). When the transfer of electric charge to the capacitor (C2) is completed, a reverse discharge current tends to flow to the capacitor (C2), but the switch (SR) blocks the reverse current and stops the preionizing discharge. Simultaneously, the magnetic core of the transformer (20) is saturated, and transfer of electric charge to a peaking capacitor (C4) from the capacitor (C2) is started. As a result, the voltage across the capacitor (C4) rises to a discharge start voltage, resulting in laser oscillation.</p> |
