JP4352871B2 - Pulse-driven laser diode-pumped Q-switched solid-state laser oscillator and its oscillation control method - Google Patents

Description

  The present invention relates to a Q-switch oscillation solid-state laser oscillator using a pulse-driven laser diode as an excitation light source and an oscillation control method thereof.

The pulse-excited Q-switch oscillation solid-state laser oscillator generates laser light having a short pulse width of several nanoseconds, and is therefore used mainly for laser processing applications that require high peak output mainly for fine processing. Also in this type of laser oscillator, the conventional flash lamp is used as a pumping light source, and the current mainstream method is to use a laser diode having an advantage such as high efficiency and downsizing as a pumping light source.
A pulse-excited Q-switched solid-state laser oscillator generally excites a solid-state laser medium such as Nd: YAG, Nd: YLF, Nd: YVO4 by driving a laser diode with a pulse current, and a laser using a Q switch. A high peak output laser is obtained by accumulating high energy during the oscillation stop state and setting the laser oscillation start state by the Q switch at a timing close to immediately before the fluorescence lifetime, which is the energy storage possible time of the laser medium.
FIG. 5 shows a general configuration of a pulse-pumped Q-switched solid-state laser laser oscillator. A laser head unit 10 comprising a laser resonator 1, a solid state laser medium 2, an excitation laser diode 3 and a Pockels element 4 for Q-switch operation, a pulse current source 5 for driving the laser diode, and an excitation laser diode A laser diode control unit 20 having a function 7 for cooling and controlling the temperature, a high voltage switching power source 6 for driving the Pockels element, a pulse current of the laser diode, and a high voltage pulse applied to the Pockels element. And a Q switch element control unit 30 including the synchronization unit 8.
When this type of laser oscillator is used for industrial applications such as laser processing, the output energy, Q-switch pulse width, and repetition frequency, which are parameters of the pulse laser beam, are automatically controlled so that optimum processing conditions can be obtained. It is required to be able to do it. Here, the Q switch pulse width is determined almost uniquely from the principle of the Q switch oscillation when the configuration in the resonator design is determined, so the degree of freedom in adjustment during processing is small, but the optical energy and the repetition frequency of the laser light are small. Are often switched and used so as to suit the processing form, processing time, and processing quality.
For example, in a laser repair device that corrects a defective portion of a fine circuit pattern such as a liquid crystal panel substrate, while processing a single shot or several shots or moving a laser irradiation position when removing an excessive pattern in terms of points Since it is necessary to switch laser irradiation conditions depending on processing conditions such as high-repetition processing for cutting a pattern in a line, control of output energy level and repetition frequency is required.

  As described above, when it is necessary to change the output energy of the pulse laser beam or the laser beam generation conditions of the Q switch pulse repetition frequency, the conventional method is to set the current value of the pulse drive current of the laser diode that is the excitation source. A method of moving up and down and changing a pulse repetition frequency is used (for example, see Patent Document 1).

JP-A-11-135870 (page 3-6, FIG. 1)

FIG. 6 shows a timing chart of the pulse drive current 11, the Q switch element applied voltage 12, and the Q switch pulse output 13. The current pulse time width W of the laser diode is fixed because the maximum Q-switch pulse energy of the laser beam can be obtained by setting the current pulse time width W to a value close to the upper level fluorescence lifetime inherent to the laser medium. The timing Δt for switching the high voltage applied to the Pockels element that performs Q switch control is adjusted and fixed near the end of the current pulse of the laser diode. The product of the pulse current value I _LD and Δt indicated by the hatched portion corresponds to the energy accumulated in the laser medium, and the oscillating Q switch energy is determined. For this reason, the Q switch energy 13 can be adjusted by adjusting the pulse current value _ILD .
On the other hand, the oscillation wavelength of the laser diode is shifted by the semiconductor chip temperature of the laser diode. It is known that a general laser diode changes with a shift amount of about 0.3 nm / ° C. with respect to the case temperature of the laser diode. Further, the oscillation wavelength of a commercially available laser diode has an individual difference of about ± 3 nm depending on production yield even when the case temperature is set to the same temperature.
The absorption characteristic of the excitation light on the laser medium side has a characteristic that only a wavelength in the range of several nm is effectively absorbed with respect to the central wavelength of a certain absorption peak. For example, in an Nd: YLF crystal, the full width at half maximum is about 2 nm with respect to an absorption peak with a wavelength of 798 nm that is generally used. For this reason, in general, the case temperature is adjusted to make the oscillation wavelength of the laser diode coincide with the absorption peak of the laser medium, whereby efficient excitation is performed to obtain a laser output. The configuration diagram of FIG. 5 also includes a function 7 for temperature control for keeping the set value constant while detecting the case temperature T _LD of the laser diode.
However, since there is a thermal resistance between the chip and the case, there is a difference between the chip temperature and the case temperature, which is the detection temperature of the control system, and the amount of heat generated by a resistive load with respect to the current of a certain laser diode. On the other hand, even if control is performed to keep the case temperature constant, the chip temperature as a heat source changes somewhat. There is also a transient characteristic in time. For this reason, optimization of the laser diode oscillation wavelength by temperature adjustment is performed under specific heat generation conditions, that is, under specific pulse drive current value and repetition frequency drive conditions of the laser diode. In particular, in a pulse excitation laser oscillator, since the repetition of the laser diode driving pulse current is changed from a single shot to several tens to several hundreds Hz, the amount of heat generation changes from several tens to several hundreds times. In the conventional technology that controls the laser pulse output level and the laser pulse repetition frequency by adjusting both the current value and the frequency of the drive pulse of the laser diode, the wavelength is optimal under the repetition condition for the above reason, and the laser is effectively used. Although an output is obtained, the wavelength is deviated in other repetition conditions, and as a result, the laser output is reduced.
In order to cope with this problem, for each laser diode having individual differences in characteristics, temperature conditions where the wavelength is constant according to various driving pulse current conditions are measured and stored, and the pulse current value and A method of controlling the temperature of the laser diode to the stored temperature condition when a repetition condition is given can be considered, but it is not practical from the viewpoint of producing an industrial laser oscillator.

  The present invention has been made in view of the problems of the control method of the conventional pulse-driven laser diode-pumped Q-switched solid-state laser oscillator as described above. The object of the present invention is to provide a pulse-driven laser diode. The Q-switch oscillation solid-state laser oscillator used has a controllable laser light source that can specify the repetition frequency and output energy of the Q-switch pulse independently by providing means and method for suppressing fluctuations in the oscillation wavelength of the laser diode. It is to provide.

In order to solve the above problems, a pulse-driven laser diode-pumped Q-switched solid-state laser oscillator of the present invention is a Q-switched solid-state laser oscillator using a pulse-driven laser diode as an optical pumping element of a laser medium, A laser diode driving means for driving a laser diode by fixing a plurality of diode pulse driving conditions to a predetermined condition; a laser diode temperature control means for controlling the laser diode to an optimum temperature under the fixed pulse driving conditions; and a Q-switch element control means for varying the driving timing of the Q switch element to rise to Q-switch oscillation, the Q-switch element control means, independently and output energy and the period of oscillation Q-switched pulsed solid-state laser oscillator It is characterized by variable control.
The pulse driving conditions of the plurality of laser diodes to be fixed are preferably a pulse current value, a pulse time width, and a pulse repetition period.
The optimum temperature of the laser diode is controlled to be constant, the oscillation wavelength of the laser diode is preferably a temperature at which the absorption peak wavelength of the laser medium.
Oscillation variable control of the Q-switched pulse output energy can be configured to perform by varying the driving timing of the Q switch element in the laser diode within the pulse duration of the drive pulse.
Further, the variable control of the oscillation Q-switched pulse period, n times the pulse period of the driving cycle laser diode driving pulses of the Q-switch element (n is a positive integer) I row by discretely variably.
The drive pulse time width of the laser diode is preferably the upper level fluorescence lifetime of the laser medium.
The discrete change of the driving period of the Q switch element is a combination of a repetition frequency of the laser diode driving pulse set in advance corresponding to the type of repetition frequency of the laser light and a repetition frequency of the Q switch element. 1 is selected according to the magnitude of n, and the repetition frequency of the selected laser diode drive pulse is externally input to the laser diode drive means and the Q switch element control means, and the selected Q switch element By inputting a repetition frequency from the outside to the Q switch element control means, the pulse period of the laser diode drive pulse and the drive period of the Q switch element can be set.

Also, the oscillation control method for a pulse-driven laser diode-pumped Q-switched solid-state laser oscillator of the present invention comprises a plurality of laser diodes in a Q-switched solid-state laser oscillator using a pulse-driven laser diode as an optical pumping element of a laser medium The laser diode is driven with the pulse drive condition fixed to a predetermined condition, the laser diode is controlled to an optimum temperature under the fixed pulse drive condition, and the drive timing of the Q switch element that causes Q switch oscillation is varied. , characterized by variably controlling the output energy and the period of oscillation Q-switched pulsed solid state laser oscillator independently.
The pulse driving conditions of the plurality of laser diodes to be fixed are preferably a pulse current value, a pulse time width, and a pulse repetition period.
The optimum temperature of the laser diode is controlled to be constant, the oscillation wavelength of the laser diode is preferably a temperature at which the absorption peak wavelength of the laser medium.
Oscillation variable control of the Q-switched pulse output energy can be configured to perform by varying the driving timing of the Q switch element in the laser diode within the pulse duration of the drive pulse.
Further, the variable control of the oscillation Q-switched pulse period, n times the pulse period of the driving cycle laser diode driving pulses of the Q-switch element (n is a positive integer) I row by discretely variably.
The drive pulse time width of the laser diode is preferably the upper level fluorescence lifetime of the laser medium.
The discrete change of the driving period of the Q switch element is a combination of a repetition frequency of the laser diode driving pulse set in advance corresponding to the type of repetition frequency of the laser light and a repetition frequency of the Q switch element. 1 is selected according to the magnitude of n, and the repetition frequency of the selected laser diode drive pulse is externally input to the laser diode drive means and the Q switch element control means, and the selected Q switch element By inputting a repetition frequency from the outside to the Q switch element control means, the pulse period of the laser diode drive pulse and the drive period of the Q switch element can be set.

The first effect of the present invention is that, in a Q-switch oscillation solid-state laser oscillator using a pulse-driven laser diode, the output energy does not change even if the pulse repetition frequency is adjusted. Provided is a laser light source with high controllability that can be specified independently.
The second effect is that the resonator alignment can be maintained in an optimum state with respect to a fixed excitation distribution by setting the laser diode driving condition to a semi-fixed state and exciting the laser medium at an optimum wavelength. Instability factors due to changes are suppressed, leading to improved stability of the intensity distribution of the laser beam transverse mode and output energy.
The third effect is that the controllability of the laser oscillator is improved, so that the machining output can be precisely controlled without using an output adjusting attenuation device or an external shutter for waiting for a stable state in the external optical system of the machining device. It becomes possible and leads to downsizing of the processing equipment.

  Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a pulse-driven laser diode-pumped Q-switched solid-state laser oscillator according to the present invention.
The laser oscillator includes a laser head unit 10, a laser diode control unit 20, and a Q switch element control unit 30.
The laser head unit 10 includes a laser resonator 1, a solid-state laser medium 2, an excitation laser diode 3, and a Pockels element 4 for Q-switch operation.
The laser diode control unit 20 includes a pulse current source 5 for driving the laser diode, a temperature control unit 7 for controlling the temperature of the excitation laser diode, and an oscillator 9 for oscillating a constant pulse repetition frequency f _LD .
The Q switch element control unit 30 includes a high voltage switching power supply 6 for driving the Pockels element and a synchronization unit 8 for synchronizing the high voltage pulse applied to the Pockels element with the laser diode drive pulse.

In the laser diode control unit 20, in response to the signal of the repetition frequency f _LD oscillated by the oscillator 9, the pulse current source 5 adds the current value I _LD and the repetition frequency f _LD which is the pulse driving condition of the laser diode. The current pulse width W is also fixed to a constant value and output. These integral values correspond to the average electric energy given to the laser diode. Fixing this integrated value to a constant value means that the average heat generation amount of the laser diode is kept constant.
The temperature control unit 7 oscillates the laser diode case temperature T _LD with individual differences under the condition that the current value I _LD and the current pulse width W and the repetition frequency f _{LD which} are pulse driving conditions of the laser diode are constant. Fix and fix so that the wavelength is the optimum wavelength. That is, while detecting a change in case temperature due to heat generation in the diode chip, temperature control is performed by an electronic cooling element such as a Peltier element so that the oscillation wavelength of the laser diode matches the absorption peak wavelength of the laser medium. Control case temperature.
In addition, the period during which the laser diode driving conditions are fixed is a short-term time range in which a series of laser processing is performed, for example, an increase in current value for correcting the amount of light generated due to laser diode consumption. It is desirable that the pulse current source 5 has the above functions.
In Q-switching element control unit 30, a Q-switch delay time Δt from the laser diode driving pulse rise from the outside to the synchronization section 8, and a repetition frequency f _PC Q-switch are entered. Further, the laser diode driving pulse repetition timing signal f _LD from the oscillator 9 are entered. Thus, the synchronization unit 8 generates a laser diode Q-switch drive signal 12 which is synchronized to the drive pulse repetition timing signal f _LD.
The high voltage switching power supply 6 converts the generated signal into a high voltage signal HV and applies it to the Pockels element 4.

FIG. 2 shows a timing chart of the Q switch operation according to the laser oscillator configuration of the present invention. First, a laser diode timing signal f _LD is generated by the oscillator 9 in response to a laser diode start signal ST given from the outside, and the laser diode is started to be driven. The drive pulse current 11 of the laser diode is set to a current value I _LD and a current pulse width W at which the expected maximum Q switch pulse energy can be obtained. The current pulse width W is set to a value close to the upper level fluorescence lifetime specific to the laser medium. The repetition frequency f _{LD of} the laser diode is also set to the maximum value necessary for the processing conditions when the solid laser output is used for laser processing or the like within the performance guarantee range of the laser diode.
When the drive condition of the laser diode is determined such, determines the heat generation amount of the laser diode by adjusting a case temperature of the laser diode T _LD, a semiconductor chip temperature T _CHIP emitting portion Sadamari the optimum temperature The excitation oscillation wavelength of the laser diode can be fixed in accordance with the absorption peak wavelength of the laser medium. The temperature controller 7 controls the temperature of the case while detecting a change in case temperature due to heat generation in the diode chip, and reaches the case temperature T _LD where the oscillation wavelength of the laser diode matches the absorption peak wavelength of the laser medium. It becomes stable at the time and enters a standby state.
Next, the Q switch delay timing time Δt and the Q switch repetition signal f _PC are input to the synchronization unit 8 from the outside, whereby the Q switch element drive signal of the repetition signal f _PC synchronized with the timing signal f _LD of the laser diode. 12 is generated, converted into a high voltage signal HV, and applied to the Pockels element 4 to oscillate the Q switch pulse laser beam 13.

To vary the repetition frequency of the laser oscillator changes the Q-switch repetition signal f _PC. That is, if f _PC having a frequency condition of 1 / n division with respect to the repetition frequency f _LD of the pulse current of the laser diode is given (f _PC = f _LD / n: n is an integer), this new f _PC Laser light having a repetition frequency is generated.
The pulse energy of the laser beam can be changed by changing the Q switch delay time Δt. In other words, the maximum Q switch pulse energy can be obtained by making Δt substantially coincide with the current pulse width W of the laser diode, and if the timing for applying the Q switch by adjusting Δt is adjusted, the accumulation of the laser medium extracted as the Q switch energy is obtained. The energy is reduced, and the output energy of the laser beam can be adjusted.
The functions created by the present invention include the laser diode drive control function of the laser diode control unit 20 capable of the series of controls described above and the Q switch timing control function of the Q switch element control unit 30 for driving the Pockels element. Is a composite.

Next, the operation of the temperature control unit 7 will be described.
FIG. 3 shows the tendency of the change in the oscillation wavelength λ with respect to the repetition frequency f _LD of the pulse current of the laser diode, which can be measured in advance before the assembly of the fixed laser oscillator.
The conventional method of adjusting the case temperature and optimizing the laser diode oscillation wavelength is performed under specific heat generation conditions, that is, under the specific pulse drive current value and repetition frequency drive condition of the laser diode as described above. Yes. This temperature control method will be described with reference to FIG. 3. A characteristic curve 21 is a λ-f _LD characteristic at a case temperature serving as a reference such as a room temperature of the laser diode. The conventional temperature control function sets the case temperature of the laser diode to T ₂ so that the oscillation wavelength of the laser diode matches the absorption peak wavelength λ _ab of the laser medium at a specific pulse repetition frequency f _mid , and λ− f This is a method in which the characteristic of _LD is shifted from 21 to 22 and controlled to a constant value. Even when the case temperature of the laser diode is set to T ₂ and controlled to a constant value, if the heat generation amount of the semiconductor chip portion, which is a heat source, increases or decreases due to repetitive changes, the case and the semiconductor chip have thermal resistance, so the chip temperature T _CHIP changes. A change in the chip temperature T _CHIP causes a change in the oscillation wavelength λ of the laser diode. In particular, when the laser diode is pulse-driven, the wider the range of repetition frequencies used, the greater the range of heat generation, and the wider the range of wavelength changes than the absorption peak width (shaded area) of the laser medium. The laser output is reduced.
On the other hand, in the method of the present invention, as described above, the laser diode drive repetition frequency f _LD is within the performance guarantee range of the laser diode, and the maximum output frequency required for the laser processing conditions, for example, is required. It is fixed to f _MAX (characteristic 23). Under this constant condition, the temperature controller 7 controls the laser diode case temperature T _LD to T ₁ to stabilize the oscillation wavelength of the laser diode at the absorption peak wavelength λ _ab of the laser medium.
In this method, even if the laser output is controlled by changing the timing Δt of the Q switch or the Q switch repetition frequency f _pc is changed, f _LD remains f _MAX and does not change, so there is no wavelength deviation. .

The features of the output control and oscillation repetition control of the laser oscillator of the present invention described above for the configuration and operation will be described.
Shaded area determined by the Q-switch delay time Δt and the pulse current value I _LD is equivalent to the stored energy of the laser medium at the time of performing Q-switch is a pulse energy 13 of the laser oscillator output light correlation. For this reason, the characteristics of the Q switch delay time Δt and output energy are measured in advance and tabulated, so that the laser oscillator output can be controlled by this table.
When this output control method is compared with the conventional method in which the solid-state laser oscillator output control is performed by controlling the current value of the laser diode, the pump wavelength shift inevitably becomes a problem in the conventional method. The change in absorption when the excitation light enters the laser medium, that is, a change in the excitation distribution, appears as a change in the intensity distribution of the laser light beam transverse mode, leading to instability due to fluctuations. Thus, this effect is suppressed when the excited state is fixed.

When the laser oscillation repetition is changed, f _PC (f _PC = f _LD / n) having a frequency condition obtained by dividing the Q switch repetition signal f _PC with respect to the repetition frequency f _LD of the pulse current of the laser diode. : N is an integer), a low repetition laser beam is generated. FIG. 2 shows a state where n = 2.
At this time, it is the same as thinning out the laser oscillation, and the output laser pulse energy does not change even if the repetition frequency is changed. Further, even if the repetition frequency is changed, the thermal state of the laser medium to be excited does not change and is constant, so that the resonator alignment can always be kept in the optimal adjustment state. This leads to an improvement in output stability because there is no deviation in resonator alignment caused by a change in excitation distribution and thermal distortion due to the repetition frequency f _LD of the pulse current as in the prior art.
However, with this method, the repetition frequency cannot be finely adjusted with the same amount of change, but in normal laser processing, switching between several types or single shots is often sufficient, and the maximum repetition f _MAX is excited. By selecting the repetition frequency f _LD of the laser diode for use, there are few practical problems.

As described above, the laser oscillator of the present invention has the following effects.
The first effect is that, in a Q-switch oscillation solid-state laser oscillator using a pulse-driven laser diode, the output energy remains unchanged even if the pulse repetition frequency is adjusted, so that the repetition frequency and output energy can be specified independently. A laser light source with good characteristics is provided.
The second effect is that by fixing the laser diode driving conditions and exciting the laser medium at the optimum wavelength, the resonator alignment can be maintained in an optimum state with respect to a constant excitation distribution. This is to suppress the laser light beam transverse mode intensity distribution and improve the stability of the output energy.
The third effect is that the controllability of the laser oscillator is improved, so that the machining output can be precisely controlled without using an output adjusting attenuation device or an external shutter for waiting for a stable state in the external optical system of the machining device. It becomes possible and leads to downsizing of the processing equipment.

  In general, as a Q switch system, there are an on-switch system that oscillates when a high voltage is applied, and an off-switch system that oscillates when the high voltage is turned off after applying a high voltage to stop laser oscillation. Either method may be used. In addition to the electro-optic effect element, an acoustic effect element may be used as necessary.

Next, a second embodiment of the present invention will be described in detail with reference to FIG.
FIG. 4 shows a laser diode control unit 20 and a Q switch element control unit 30 excluding the laser head unit 10 in the configuration of the laser oscillator of FIG.
In the first embodiment described above, the repetition frequency f _LD of the laser diode is fixed. For example, when only the high repetition frequency and the low repetition frequency are used, the light emission of the laser diode that does not contribute to oscillation at the low repetition frequency. In many cases, there is a concern about the influence on the life of the laser diode. The embodiment shown in FIG. 4 has an expanded function to cope with this.
When the repetition frequency f _LD of the laser diode is high, the maximum value is selected as f1 _LD , and when the repetition frequency is low, the maximum value is selected as f2 _LD . The laser diode case temperatures T1 _LD and T2 _LD, which are optimum excitation wavelengths for each, are measured and stored. This is to provide an adjustment point 24 in addition to the adjustment point 23 shown in FIG. For each repetitive signal, the repetitive signal f _PC of the Q switch to divide satisfies a condition of f _PC = f _LD / n (n is an integer), and a plurality of f1 _PC and f2 determined by the division ratio n _{When a PC} is provided, it is possible to select various pulse repetitions, high and low.

When low repetition f2 _PC is designated from the outside, the laser diode start signal ST and the maximum frequency drive signal f2 _LD at the time of low repetition of the laser diode are given to the pulse current source 5, and the laser diode set temperature T2 _LD Is given to the temperature control function 7 to start driving the laser diode. The wavelength of the laser diode is then stabilized at the adjustment point 24 in FIG. Thereafter, when the Q switch delay time Δt for determining the pulse energy and the Q switch repeat signal f2 _PC are supplied to the high voltage switching power supply 6, laser oscillation occurs. At this time, the amount of light emission that does not contribute to the oscillation of the laser diode is less than that when driven by the drive signal f1 _LD having the maximum frequency at the time of high repetition, so that the laser diode is consumed less.
In the above example, the number of adjustment points is two, but a plurality of combinations of f _LD , f _PC , and T _LD can be externally input corresponding to the type of repetition frequency of laser light required for processing conditions. In this way, it is possible to drive the laser diode while efficiently reducing wasteful light emission.

The second embodiment has the following effects.
The first effect is that, in a Q-switch oscillation solid-state laser oscillator using a pulse-driven laser diode, the output energy remains unchanged even if the pulse repetition frequency is adjusted, so that the repetition frequency and output energy can be specified independently. A laser light source with good characteristics is provided.
The second effect is that the controllability of the laser oscillator is improved, so that the machining output can be precisely controlled without using an output adjusting attenuation device or an external shutter for waiting for a stable state in the external optical system of the machining device. It becomes possible and leads to downsizing of the processing equipment.

It is a block diagram of the 1st Example of the pulse drive laser diode excitation Q switch solid state laser oscillator of this invention. It is a timing chart showing the Q switch operation of the pulse drive laser diode pumped Q switch solid state laser oscillator of the present invention. It is a figure which shows the wavelength change in the repetition operation | movement of a laser diode. It is a block diagram of the control unit of the 2nd Example of the pulse drive laser diode excitation Q switch solid state laser oscillator of this invention. It is a block diagram of the laser oscillator of a prior art. It is a timing chart figure showing Q switch operation of a prior art laser oscillator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser resonator 2 Laser medium 3 Laser diode 4 Pockels element 5 Pulse current source 6 High voltage switching power supply 7 Temperature control function 8 Synchronizing part 9 Oscillator 10 Laser head part 11 Laser diode drive pulse current 12 Q switch element drive signal 13 Pulse Laser light 20 Laser diode control unit 30 Q switch element control unit

Claims (14)

A Q-switched solid-state laser oscillator using a pulse-driven laser diode as an optical excitation element of a laser medium,
A laser diode driving means for driving the laser diode while fixing a plurality of pulse driving conditions of the laser diode to a predetermined condition;
Laser diode temperature control means for controlling the laser diode to an optimum temperature under the fixed pulse driving condition;
A Q-switch element control means for varying the driving timing of the Q switch element to rise to the Q-switch oscillation,
With
The Q-switch element control means variably controls the output energy and the period of oscillation Q-switched pulse of the solid-state laser oscillator independently,
A pulse-driven laser diode-pumped Q-switched solid-state laser oscillator characterized by the above. The pulse driving conditions for the plurality of laser diodes to be fixed are:
The pulse current value, pulse duration, and pulse repetition period.
The pulse-driven laser diode-pumped Q-switched solid-state laser oscillator according to claim 1. The optimum temperature of the laser diode to be controlled constant is
The oscillation wavelength of the laser diode is a temperature at which the absorption peak wavelength of the laser medium is obtained.
The pulse-driven laser diode-pumped Q-switched solid-state laser oscillator according to claim 1. The variable control of the output energy of the oscillation Q switch pulse is as follows:
By varying the drive timing of the Q switch element within the pulse time width of the laser diode drive pulse,
The pulse-driven laser diode-pumped Q-switched solid-state laser oscillator according to claim 2. The variable control of the oscillation Q switch pulse period is as follows:
The drive period of the Q switch element is discretely varied by n times the pulse period of the laser diode drive pulse (n is a positive integer).
The pulse-driven laser diode-pumped Q-switched solid-state laser oscillator according to claim 2. The drive pulse time width of the laser diode is:
The upper level fluorescence lifetime of the laser medium,
The pulse-driven laser diode-pumped Q-switched solid-state laser oscillator according to claim 2. The discrete variable of the driving cycle of the Q switch element is
One combination is selected according to the size of n from the combination of the repetition frequency of the laser diode driving pulse and the repetition frequency of the Q switch element, which are set in advance corresponding to the type of repetition frequency of the laser light. Then, the repetition frequency of the selected laser diode drive pulse is inputted from the outside to the laser diode drive means and the Q switch element control means, and the repetition frequency of the selected Q switch element is inputted from the outside to the Q switch element control means. By
By setting a pulse period of the laser diode driving pulse and a driving period of the Q switch element;
The pulse-driven laser diode-pumped Q-switched solid-state laser oscillator according to claim 5. In a Q-switch oscillation solid-state laser oscillator using a pulse-driven laser diode as an optical pumping element of a laser medium,
Driving the laser diode by fixing a pulse driving condition consisting of a plurality of the laser diodes to a predetermined condition,
Controlling the laser diode to an optimum temperature under the fixed pulse driving conditions;
By varying the drive timing of the Q switch element that causes the Q switch oscillation,
Variably controlled independently an output energy and the period of oscillation Q-switched pulse of the solid-state laser oscillator,
An oscillation control method for a pulse-driven laser diode-pumped Q-switched solid-state laser oscillator characterized by the above. The pulse driving conditions for the plurality of laser diodes to be fixed are:
The pulse current value, pulse duration, and pulse repetition period.
The oscillation control method for a pulse-driven laser diode-pumped Q-switched solid-state laser oscillator according to claim 8. The optimum temperature of the laser diode to be controlled constant is
The oscillation wavelength of the laser diode is a temperature at which the absorption peak wavelength of the laser medium is obtained.
The oscillation control method for a pulse-driven laser diode-pumped Q-switched solid-state laser oscillator according to claim 8. The variable control of the output energy of the oscillation Q switch pulse is as follows:
By varying the drive timing of the Q switch element within the pulse time width of the laser diode drive pulse,
The oscillation control method for a pulse-driven laser diode-pumped Q-switched solid-state laser oscillator according to claim 9. The variable control of the oscillation Q switch pulse period is as follows:
The drive period of the Q switch element is discretely varied by n times the pulse period of the laser diode drive pulse (n is a positive integer).
The oscillation control method for a pulse-driven laser diode-pumped Q-switched solid-state laser oscillator according to claim 9. The drive pulse time width of the laser diode is:
The upper level fluorescence lifetime of the laser medium,
The oscillation control method for a pulse-driven laser diode-pumped Q-switched solid-state laser oscillator according to claim 9. The discrete variable of the driving cycle of the Q switch element is
One combination is selected according to the size of n from the combination of the repetition frequency of the laser diode driving pulse and the repetition frequency of the Q switch element, which are set in advance corresponding to the type of repetition frequency of the laser light. Then, the repetition frequency of the selected laser diode drive pulse is inputted from the outside to the laser diode drive means and the Q switch element control means, and the repetition frequency of the selected Q switch element is inputted from the outside to the Q switch element control means. By
By setting a pulse period of the laser diode driving pulse and a driving period of the Q switch element;
13. The oscillation control method for a pulse-driven laser diode-pumped Q-switched solid-state laser oscillator according to claim 12.

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