JPH05347447A - Laser oscillator - Google Patents

Abstract

PURPOSE:To extend the effective setting range of a high-frequency output to a high-frequency power supply. CONSTITUTION:A control circuit 1 reads an allowable upper-limit duty value, where no plate loss is generated in a high-frequency power supply 2 stored to the output set value of the control circuit, when the output set value and a duty set value are given. The control circuit 1 outputs a duty command value corresponding to the allowable upper-limit duty value to a pulse generating circuit 4 when the duty set value is larger than an allowable upper-limit duty set value. The pulse generating circuit 4 outputs a pulse signal based on the duty command value to the high-frequency power supply 2. The high-frequency power supply 2 outputs high-frequency power based on the output set value and the pulse signal to a resonator 3. The resonator 3 emits laser beams having an output corresponding to the magnitude of high-frequency power.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser oscillating device for outputting laser light from a resonator in response to supply of high frequency power from a high frequency power source.

[0002]

2. Description of the Related Art Conventionally, in an RF type laser oscillator,
High frequency power corresponding to the set laser output is supplied from the high frequency power supply to the resonator. Therefore, laser light having an output corresponding to the high frequency power is emitted from the resonator. At this time, if the reflected power from the resonator exceeds the allowable value, the laser gas does not reach the so-called negative temperature state, so that it is not possible to emit the laser light with a sufficient output, so the set value of the laser output is When the reflected power from the resonator is set in a range exceeding the allowable value, so-called truncation for forcibly setting the output from the high frequency power source to zero is performed.

On the other hand, when the laser output of the RF laser oscillator is set low, the power loss (in the power consumed in the output stage of the high frequency power supply due to the impedance mismatch between the high frequency power supply and the resonator) , Called plate loss) may become excessive. Therefore, conventionally, when the set value of the laser output is equal to or less than the allowable output, a protection circuit for not accepting the setting is added to carry out the above-mentioned truncation. Therefore, when the laser output is set to be lower than the allowable range, the high frequency power is not output from the high frequency power supply, so that it is possible to prevent the power loss from increasing inside the high frequency power supply.

[0004]

However, in the case of the above-mentioned conventional structure, the cutoff to the high frequency power source is performed when the voltage is set to a predetermined output voltage or less, so that the effective setting range of the laser output is set. Has the drawback that it is very limited.

The present invention has been made in view of the above circumstances, and an object thereof is to prevent the output loss of the high frequency power source from becoming excessive and to expand the effective setting range of the laser output. It is to provide an oscillating device.

[0006]

SUMMARY OF THE INVENTION The present invention is a laser oscillating device for outputting laser light from a resonator in response to supply of high frequency power from a high frequency power source, when an output set value and a duty set value are given. A control means for driving the high frequency power source based on those set values is provided, and the control means controls the allowable upper limit duty value, which is the upper limit of the allowable range in which the power loss of the high frequency power source is allowable, to correspond to the output set value. And a duty setting value for the high frequency power source is changed to the allowable upper limit duty value when the duty setting value exceeds the allowable upper limit duty value stored corresponding to the output setting value. It was done.

[0007]

When the output setting value and the duty setting value are given to the control means, the control means drives the high frequency power source according to the set contents. As a result, high-frequency power corresponding to the output set value and the duty set value is applied from the high-frequency power supply to the resonator, and the resonator emits laser light with an output according to the high-frequency power.

Now, when the output setting value and the duty setting value are given, the control means is the upper limit of the permissible range in which the power loss of the high frequency power source stored corresponding to the output setting value does not become excessive. The allowable upper limit duty value is read, the allowable upper limit duty value is compared with the duty setting value, and when the duty setting value exceeds the allowable upper limit duty value, the duty setting value for the high frequency power supply is changed to the allowable upper limit duty value. The high frequency power supply is driven in this state. As a result, even when the high frequency output determined by the output set value and the duty set value is set in a range where the power loss of the high frequency power source is excessive, the power loss is suppressed and the laser light is efficiently output. be able to.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the overall schematic configuration. This Figure 1
In, the control circuit 1 is provided to input the output set value and the duty set value. These output set value and duty set value are parameters for determining the output waveform of the high frequency power output from the high frequency power supply 2 to the resonator 3. The control circuit 1 stores an allowable upper limit duty value for the output set value. The allowable upper limit duty value is an upper limit value of an allowable range in which plate loss does not occur inside the high frequency power supply 2. That is, in FIG. 2 showing the relationship between the output set value and the plate loss over region, when the high frequency output determined by the output set value and the duty value for the high frequency power source 2 is set in the shaded region in the drawing,
Since the internal output loss of the high-frequency power source 2 is in the plate loss over region where it becomes excessive, the allowable upper limit duty value, which is the allowable range outside the plate loss over region, is stored in correspondence with the output set value. is there.

The control circuit 1 is provided with a comparison processing unit 1a. When an output set value and a duty set value are given, the control circuit 1 stores the allowable upper limit duty corresponding to the output set value as shown in FIG. The value and the given duty set value are compared in the comparison processing unit 1a, the output set value is output to the high frequency power source 3 based on the processing result, and the duty command value corresponding to the duty set value is output to the pulse generator 4 Output to.

The pulse generation circuit 4 which constitutes the control means together with the control circuit 1 is adapted to input the pulse frequency set value. When the duty command value is given from the control circuit 1, the duty command value and the pulse are set. A pulse signal is generated based on the frequency setting value and output to the high frequency power supply 2. The high frequency power supply 2 generates high frequency power based on the output set value from the control circuit 1 and the pulse signal from the pulse generation circuit 4, and outputs the high frequency power to the resonator 3. The resonator 3 emits laser light having an output corresponding to the high frequency power supplied from the high frequency power supply 2.

Next, the operation of the above configuration will be described. FIG. 3 is a flowchart showing the operation of the control circuit 1. In FIG. 3, when the control circuit 1 inputs the output set value and the duty set value (step S1), the step S1 is executed.
In step 2, the allowable upper limit duty value stored corresponding to the input output set value is read, and the allowable upper limit duty value is compared with the duty set value input in step S1. At this time, if the duty setting value is less than or equal to the allowable upper limit duty value, the control circuit 1
Advances from step S3 to step S4 and outputs a duty command value according to the duty set value to the pulse generation circuit 4 and outputs the output set value input in step S1 to the high frequency power source 2 (step S5). .

On the other hand, when the duty command value is given from the control circuit 1, the pulse generating circuit 4 generates a pulse signal based on the duty command value and the preset pulse frequency setting value and outputs it to the high frequency power supply 2. To do. Then, the high frequency power supply 2 generates high frequency power based on the output set value from the control circuit 1 and the pulse signal from the pulse generation circuit 4, and outputs the high frequency power to the resonator 3. As a result, the resonator 3 emits laser light having an output according to the high frequency power from the high frequency power supply 2.

When the duty setting value input in step S1 exceeds the allowable upper limit duty value read in step S2, the control circuit 1 shifts from step S3 to step S6 to set the allowable upper limit duty value. The corresponding duty command value is output to the pulse generation circuit 4.
As a result of such an operation, when the high frequency output determined by the output setting value and the duty setting value given to the control circuit 1 becomes the plate loss over region (hatched region) shown in FIG. The value is changed to the allowable upper limit duty value read in the stitch S2.

Then, the control circuit 1 outputs a duty command value corresponding to the allowable upper limit duty value to the pulse generation circuit 4. As a result, the pulse generation circuit 4 outputs a pulse signal corresponding to the allowable upper limit duty value to the high frequency power supply 2, so that the high frequency power supply 2 has the output set value set in the control circuit 1 and is set in the control circuit 1. The high frequency power is generated based on the allowable upper limit duty value lower than the duty setting value and output to the resonator 3. As a result, the resonator 3 emits laser light having an output according to the output set value given to the control circuit 1.

According to the above configuration, when the high frequency output determined by the output set value and the duty set value set in the control circuit 1 is in the plate loss over range of the high frequency power supply 2, the duty is set by the control circuit 1. Since the high frequency power supply 2 is driven with the value changed to the allowable upper limit duty value outside the plate loss over range, even if the high frequency output is set in the plate loss over range, 2 It is possible to prevent the power loss in the inside from becoming excessive. Therefore, the effective setting range for the high frequency power supply 2 can be expanded, unlike the conventional example in which the output is switched to zero when the output setting for the high frequency power supply is less than the allowable value.

[0017]

As is apparent from the above description, according to the laser oscillator of the present invention, the control means sets the allowable upper limit duty value, which is the upper limit of the allowable range in which the power loss of the high frequency power source is allowable, to the output setting. A value corresponding to the value is stored, and when the duty setting value exceeds the allowable upper limit duty value stored corresponding to the output setting value, the duty setting value for the high frequency power supply is changed to the allowable upper limit duty value. With this configuration, it is possible to expand the effective setting range of the laser output while preventing the output loss of the high frequency power source from becoming excessive.

[Brief description of drawings]

FIG. 1 is a block diagram schematically showing the configuration of an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between an output set value and a plate loss over region.

FIG. 3 is a flowchart showing the operation of the control circuit.

[Explanation of symbols]

Reference numeral 1 is a control circuit (control means), 2 is a high frequency power source, 3 is a resonator, and 4 is a pulse generator (driving means).

Claims (1)

[Claims] 1. A laser oscillating device for outputting laser light from a resonator in response to supply of high-frequency power from a high-frequency power supply, when an output set value and a duty set value are given, based on those set values. A control means for driving the high frequency power supply is provided, and the control means stores an allowable upper limit duty value, which is an upper limit of an allowable range in which the power loss of the high frequency power supply is allowable, in association with the output set value, When the value exceeds the allowable upper limit duty value stored corresponding to the output set value, the duty setting value for the high frequency power source is changed to the allowable upper limit duty value. apparatus.