JPH0626261B2 - Laser pump - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a laser pumping device, and particularly to a laser pumping device capable of stably generating a large output laser beam in a metal vapor laser using a metal vapor as a laser medium. Regarding

[Conventional technology]

2. Description of the Related Art In recent years, lasers using a metal vapor having a high repetition frequency and capable of generating a high output with high efficiency are being applied in fields such as uranium enrichment using lasers and medical treatments using lasers. As the metal vapor, for example, copper (laser wavelength 511 nm, 578 nm), gold (62
8 nm) and the like.

These metal vapor lasers have an excitation circuit configuration as shown in FIG. For example, regarding a copper vapor laser, an outline of the operation will be described with reference to FIG. The output charge from the DC power source V ₀ of the charging power source 1 is accumulated in the charging capacitor C, and further, the charging inductance L and the diode 2
2, discharging capacitor 2 following the path of charging resistor 2
Stored in 3. After the discharging capacitor 23 is charged, it is output from the pulse generator 20 and the grid driving circuit 2
The signal shaped into a predetermined voltage by 1 is input to the grid of the switching element 24, and the switching element 2
Make 4 conductive. The electric charge accumulated in the discharging capacitor 23 is charged into the peaking capacitor 4 by this conduction, but normally the value of the peaking capacitor 4 is set to a fraction of the value of the discharging capacitor 23, so the peaking capacitor 4 is set. The voltage generated at both ends of 4 is several times higher than the charging voltage of the discharging capacitor 23. As a result, the discharge buffer gas contained in the laser tube 3 is ionized.

The ionized buffer gas collides with and excites the metal vapor contained therein to form a laser action. What is important here is that the lifetime of the upper level of the laser of metal vapor, which is the laser medium, is as short as about several tens of nanoseconds. Must be done at a time equal to or shorter than the time value of. Therefore, the discharging capacitor 23, the peaking capacitor 4, and the switching element 24 are selected to be suitable for short-time operation, and the circuit configuration including the laser tube 3, the vapor capacitor, and the switching element is also suitable for short-time operation. Composed. Installation of the peaking capacitor 4 is also 1
It is regarded as one means.

The thyratron is the most commonly used switching element 24 in the excitation circuit of the metal vapor laser described above. Thyratron is well known as a high voltage / high current switching element.

[Problems to be solved by the invention]

However, the above-described conventional laser pumping device has the following problems. That is, the thyratron is 10 to 2 which is a typical operating condition in an actual metal vapor laser.
It is said that the maximum electric power capacity that can be handled by the thyratron is at most about 10 kW when it is operated at a high voltage of about 0 V for a short time of several tens of nanoseconds.
Therefore, when increasing the output of the metal vapor laser, there is a drawback that the upper limit of the output is limited by the thyratron.

An object of the present invention is to eliminate the above-mentioned drawbacks and to provide a laser pumping device capable of discharging a high power laser tube even if a thyratron having a small power capacity is used as a switching element.

[Means for solving problems]

The laser pumping device of the present invention includes a charging resistor and a peaking capacitor, each of which includes a discharging capacitor, a backflow prevention diode, and a switching element, and which shares a charging resistor and a peaking capacitor that are arranged in parallel with the laser tube to be excited. A plurality of charging / discharging circuits arranged in parallel with the laser tube, a plurality of switching element driving circuits for driving each switching element of the plurality of charging / discharging circuits, and an operation of the switching element driving circuit. And a plurality of delay circuits for adjusting timing so as to compensate for variations in the characteristics of the plurality of charge / discharge circuits.

〔Example〕

 Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention. The embodiment shown in FIG. 1 is a charging power source 1, a charging resistor 2, a laser tube 3, a peaking capacitor 4, a discharging capacitor 5 to 7 for accumulating charges to be discharged to the laser tube 3, and each of the above capacitors. Charging inductance L and charging resistor 2 for charging to the backside, backflow prevention diodes 8 to 10 for preventing the backflow of the electric charge stored in the discharging capacitors 5 to 7 and storage in the discharging capacitors 5 to 7 Switching elements 11 to 13 for discharging the generated electric charge,
A peaking capacitor 4, which functions to apply a voltage higher than the charging voltage to the laser tube 3, and a diode 8 for preventing backflow.
10, discharging capacitors 5 to 6 and switching element 11
To 13 are connected in parallel, a plurality of charging / discharging circuits connected in parallel, in the case of this embodiment, three charging / discharging circuits 25, and a switching element driving circuit for driving the switching elements 11 to 13 are included. 17-19, delay circuit 14 for adjusting the timing of operation of the switching element drive circuit
16 and a pulse generator 20.

Next, the operation of the laser pumping apparatus of this embodiment will be described. If the power capacity required to excite the laser tube 3 cannot be handled with only one switching element, the required power can be provided by adding the charging / discharging circuit including a plurality of switching elements as described above. Can be supplied to. Here, in each charge / discharge circuit, a slight timing shift may occur due to variations in the performance of the backflow prevention diodes 8 to 10, the discharge capacitors 5 to 7, and the switching elements 11 to 13 that are included. In order to improve this, in order to synchronize the time of the switches of the respective switching elements, the switching element drive circuits 17-1
The signal input to 9 may be time adjusted using an appropriate delay circuit. The delay circuits 14 to 16 realize this. Further, in this case, the inductance of the charging / discharging circuit viewed from the laser tube 3 is low even when the charging / discharging circuit is single because a plurality of charging / discharging circuits are connected in parallel. Therefore, discharge of the laser tube having a fast rise, that is, in a short time can be obtained, which is suitable for laser operation. Further, in the backflow preventing diodes 8 to 10, even if a switching element of another charging / discharging circuit is turned on by mistake, the charge accumulated in the discharging capacitor of the charging / discharging circuit is blocked by the diode and does not flow. Therefore, it is possible to prevent the switching element that is accidentally conducted from being destroyed.

[Effect of the Invention] As described above, according to the present invention, by connecting a plurality of charging / discharging circuits consisting of a backflow prevention diode, a discharging capacitor, and a switching element in parallel with a laser tube as a load, There is an effect that a high power laser tube can be discharged even by a switching element having a small power capacity.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a laser pumping device of the present invention, and FIG. 2 is a block diagram showing a typical structure of a conventional laser pumping device. 1 ... Charging power supply, 2 ... Charging resistance, 3 ... Laser tube, 4 ... Peaking capacitor, 5-7 ... Discharging capacitor, 8-10 ... Backflow prevention die dode, 11--11
13 ... switching element, 14-16 ... delay circuit,
17 to 19 ... Switching element drive circuit, 20 ... Pulse generator, 21 ... Grid drive circuit, 22 ... Diode, 23 ... Discharge capacitor, 24 ... Switching element, 25 ... Charge / discharge circuit.

Claims (1)

[Claims] 1. A charging power source and the laser tube, each of which includes a discharging capacitor, a backflow prevention diode, and a switching element, shares a charging resistor and a peaking capacitor which are arranged in parallel with a laser tube to be excited. A plurality of charging / discharging circuits arranged in parallel between the plurality of switching elements, a plurality of switching element driving circuits for driving the switching elements of the plurality of charging / discharging circuits, and the operation timing of the switching element driving circuit. A laser pumping circuit comprising: a plurality of delay circuits that adjust so as to compensate for variations in characteristics of the plurality of charge / discharge circuits.