JPS5879788A - Driving method for q-switching laser device - Google Patents
Driving method for q-switching laser deviceInfo
- Publication number
- JPS5879788A JPS5879788A JP56178031A JP17803181A JPS5879788A JP S5879788 A JPS5879788 A JP S5879788A JP 56178031 A JP56178031 A JP 56178031A JP 17803181 A JP17803181 A JP 17803181A JP S5879788 A JPS5879788 A JP S5879788A
- Authority
- JP
- Japan
- Prior art keywords
- pulse
- switch
- peak value
- oscillation
- pulses
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/10—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
- H01S3/11—Mode locking; Q-switching; Other giant-pulse techniques, e.g. cavity dumping
- H01S3/1123—Q-switching
- H01S3/117—Q-switching using intracavity acousto-optic devices
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/10—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
- H01S3/106—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating by controlling devices placed within the cavity
- H01S3/1068—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating by controlling devices placed within the cavity using an acousto-optical device
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/10—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
- H01S3/13—Stabilisation of laser output parameters, e.g. frequency or amplitude
- H01S3/1306—Stabilisation of the amplitude
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/10—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
- H01S3/13—Stabilisation of laser output parameters, e.g. frequency or amplitude
- H01S3/136—Stabilisation of laser output parameters, e.g. frequency or amplitude by controlling devices placed within the cavity
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- Plasma & Fusion (AREA)
- Optics & Photonics (AREA)
- Lasers (AREA)
Abstract
Description
【発明の詳細な説明】 本発明は、Ｑスイッチレーザ装置の駆動方法に関する。[Detailed description of the invention] The present invention relates to a method for driving a Q-switched laser device.
Ｑスイッチを用いた固体レーザーは、尖頭出力値の極め
て高いパルスを出力することが知られており、精密加工
、レーザーレーダー、非線形光学など多方面へ応用され
ている。Solid-state lasers using Q-switches are known to output pulses with extremely high peak output values, and are used in many fields such as precision processing, laser radar, and nonlinear optics.
精密加工への応用、たとえば薄膜抵抗トリミングなどへ
応用しようとする場合、パルスの繰シ返し周波数が２Ｋ
Ｈｚ以上になると、レーザ光をオフ状態からオン状態に
した＠１発口のＱスイ、チパルスの尖頭値が大きく、こ
の個所だけ深く大きな加工軌跡を残し、基板の破損など
をひき起す危険性がある。When applying to precision machining, such as thin film resistor trimming, the pulse repetition frequency is 2K.
When the frequency exceeds Hz, the peak value of the Q-switch and chip pulse of @1 shot when the laser beam is turned from the off state to the on state is large, leaving a deep and large machining trajectory only in this area, which poses the risk of causing damage to the board. There is.
この発明の目的は、音響光学的Ｑスイッチ法において印
加する高周波電界の振幅を変えることによ１．Ｑスイッ
チレーザパルス発生直前の短時間に、レーザ共振器の損
失を減少させて１弱い連続発振を起こさせることＫよシ
飽和している反転分布量を小さくし、安定Ｋかっ、再現
性良く％Ｑスイッチパルス列の尖頭値を一定に維持しう
るＱスイ、チレーザ装置の駆動方法を提供することであ
る。The purpose of this invention is to: 1. change the amplitude of the high frequency electric field applied in the acousto-optic Q-switch method; In a short period of time just before the Q-switch laser pulse is generated, the loss of the laser resonator is reduced to cause a weak continuous oscillation.The amount of population inversion that is saturated is reduced, and stable K is achieved with good reproducibility. An object of the present invention is to provide a method for driving a Q-switch laser device that can maintain a constant peak value of a Q-switch pulse train.
次に、この発明について図面を参照して説明する。第１
図は、この発明の一実施例の概略構成を、また、第２図
は信号波形およびＱスイッチパルス波形を模型的に表わ
し九ものでおる。Next, the present invention will be explained with reference to the drawings. 1st
The figure shows a schematic configuration of an embodiment of the present invention, and FIG. 2 schematically shows signal waveforms and Q-switch pulse waveforms.
固体レーザ物質１１は、励起光源１２と集光器１３によ
り励起され１反射鏡１４．１５から構成される、レーザ
共振器中に置かれている。一方、このレーザ共振器中に
置かれ、レーザ発振をパルス化するための音響光学的変
調器１６は、溶融石英板で作られ九超音波セル１７に超
音波位相回折格子１８ｔ−形成する電気音響変換子１９
から構成されている。この電気音響変換子１９には、高
周波ドライバー２０からの高周波信号が印加されている
。高周波ドライバー２０はＶＨＦｌ例えば、４０Ｍｈで
発振する発振器２１とパルス変調回路２２、変調信号回
路２３、高周波増幅回路２４から構成され、変調信号発
生回路２３は、Ｑスイッチ制御外部信号２５によ〉制御
されている。A solid-state laser material 11 is placed in a laser cavity excited by an excitation light source 12 and a condenser 13 and consisting of one reflecting mirror 14,15. On the other hand, an acousto-optic modulator 16 placed in this laser resonator and for pulsing laser oscillation is made of a fused silica plate and forms an electroacoustic phase grating 18t in nine ultrasonic cells 17. converter 19
It consists of A high frequency signal from a high frequency driver 20 is applied to this electroacoustic transducer 19 . The high-frequency driver 20 is composed of an oscillator 21 that oscillates at VHFl, for example, 40Mh, a pulse modulation circuit 22, a modulation signal circuit 23, and a high-frequency amplification circuit 24. The modulation signal generation circuit 23 is controlled by a Q-switch control external signal 25. ing.
次にＱスイッチ制御外部信号２５、変調信号発生回路２
３およびＱスイッチパルス波形の関係會図により説明す
る。第２図の横軸は時間１−、縦軸は、信号強Ｗｔ−相
対的に表わすものである。Ｑスイッチ制御外部信号２５
の波形１０１は、Ｑスイ、千発生時間だけローレベルに
維持される。これによ抄変調信号発生回路２３は、あら
かじめ定められた周期とパルス幅１０２もしくは、１０
４の様に変化する。波形１０２は従来技術による変調信
号波形であシ、パルス幅■数μＳ１周期数ｍｓ以下で使
用されるのが普通である。もし、周期がＱ、５ｍｌ以下
であると、得られるＱスイッチパルス波形１０３は、最
初の１パルス目だけ尖頭値の高いパルス発振となってし
まう。なぜならば、変調信号１０２がハイレベルにある
間は、レーザ発振は抑止され、エネルギーが蓄積される
が、最初のパルスに対してのみ、ハイレベルの時間が長
く、反転分布が、完全に飽和するまで蓄積されるからで
ある。Ｑスイッチパルス波形１０３の第１パルスの尖頭
値は、第２パルス以降に比較し、容易に１０倍以上とな
ｐ、精密加工などの応用に対して重大な影響を与えてし
まう。Next, Q switch control external signal 25, modulation signal generation circuit 2
3 and Q switch pulse waveforms. In FIG. 2, the horizontal axis represents time 1-, and the vertical axis represents signal strength Wt-relatively. Q switch control external signal 25
The waveform 101 of is maintained at a low level for the duration of Qswidth generation. Thereby, the paper modulation signal generation circuit 23 has a predetermined period and pulse width of 102 or 10
It changes like 4. The waveform 102 is a modulation signal waveform according to the prior art, and is usually used with a pulse width of several microseconds and a cycle of several ms or less. If the period is Q, 5 ml or less, the resulting Q-switched pulse waveform 103 will be a pulse oscillation with a high peak value only at the first pulse. This is because while the modulation signal 102 is at a high level, laser oscillation is suppressed and energy is accumulated, but only for the first pulse, the high level time is long and the population inversion is completely saturated. This is because it accumulates up to The peak value of the first pulse of the Q-switch pulse waveform 103 is easily 10 times or more compared to the second and subsequent pulses, which has a serious effect on applications such as precision machining.
この発明による変調信号波形１０４は、従来波形１０２
と異なり、Ｑスイッチ制御外部信号波形１０１がローレ
ベルになった瞬間から数ｍ３の間に、変調信号の出力レ
ベルを徐々に下げ、レーザ発振が始って定常的なｃｗ発
振に達した後から約６μＳのパルス幅のパルスが繰シ返
丁よう制御されている。このためにＱスイッチパルス波
形１０６は、最初から同じパルス尖頭値を持つことにな
る。The modulated signal waveform 104 according to the present invention is different from the conventional waveform 102.
Differently, the output level of the modulation signal is gradually lowered for several m3 from the moment the Q-switch control external signal waveform 101 becomes low level, and after the laser oscillation starts and reaches steady cw oscillation. The pulses with a pulse width of about 6 μS are controlled to repeat repeatedly. For this reason, the Q-switch pulse waveform 106 has the same pulse peak value from the beginning.
この理由は、始めに変調信号の出力レベルを徐々に下げ
ることによって、弱い連続発振を起し、飽−和した、反
転分布の一部が消費されてレーザ物質内の反転分布を第
１パルスの尖頭値が後続パルスの尖頭値と等しくなるレ
ベルまで減少させることができるからである。The reason for this is that by first gradually lowering the output level of the modulation signal, a weak continuous oscillation is generated, and a part of the saturated population inversion is consumed, causing the population inversion in the laser material to change to the first pulse. This is because the peak value can be reduced to a level where it becomes equal to the peak value of the subsequent pulse.
これによって、従来の第１Ｑスイ、チパルスの尖頭値が
異常に高くなることは抑止され、ｔｌは尖頭値の等しい
Ｑスイッチパルス列が得られることになる。尚、この方
法による、第１パルスに先立りて発生するＣＷ発振パワ
ーはレベルも低く時間も短いので加工等への影響は極め
て小さいのけ明らかである。This prevents the peak values of the conventional first Q switch and pulse from becoming abnormally high, and provides a Q switch pulse train with equal peak values of tl. Note that, in this method, the CW oscillation power generated prior to the first pulse has a low level and a short time, so it is obvious that the influence on processing etc. is extremely small.
第１図はこの発明・の実施例の概略構成を示すブロック
図、第２図は信号波形およびＱスイッチパルス波形を模
型的に表わす。
１１は固体レーザ物質、１２は励起光源、１３は集光器
、１４．１５はレーザ共振器ｔ−構成する反射鏡、１６
は音響光学的変調器、１７は超音波セル、１８は超音波
位相回折格子、１９は電気音響変換子、２０は高周波ド
ライバ、２１はＶＨＦ発振器、２２はパルス変調回路、
２３は変調信号発生回路、２４は高周波増幅回路、２５
はＱスイッチ制御外部信号、１０１はＱスイッチ制御外
部信号波形、１０２は従来技術による変調信号波形、１
０３は従来技術によるＱスイッチパルス波形、１０４は
この発明による変調信号波形、１０５はこの発明による
レーザ物質内の反転分布、１０６はこの発明によって得
られるＱスイ、チパルス波形である。FIG. 1 is a block diagram showing a schematic configuration of an embodiment of the present invention, and FIG. 2 schematically shows signal waveforms and Q-switch pulse waveforms. 11 is a solid-state laser material, 12 is an excitation light source, 13 is a condenser, 14.15 is a reflecting mirror constituting a laser resonator, 16
is an acousto-optic modulator, 17 is an ultrasound cell, 18 is an ultrasound phase diffraction grating, 19 is an electroacoustic transducer, 20 is a high frequency driver, 21 is a VHF oscillator, 22 is a pulse modulation circuit,
23 is a modulation signal generation circuit, 24 is a high frequency amplification circuit, 25
1 is a Q-switch control external signal, 101 is a Q-switch control external signal waveform, 102 is a modulation signal waveform according to the prior art, 1
03 is a Q-switch pulse waveform according to the prior art, 104 is a modulation signal waveform according to the present invention, 105 is a population inversion in the laser material according to the present invention, and 106 is a Q-switch pulse waveform obtained according to the present invention.
Claims (1)
Ｑスイッチパルス発振させるに際し、Ｑスイッチパルス
が発生する直前に、Ｑスイッチへの印加損失を小さく６
１弱い連続発振を起こさせ、飽和した反転分布エネルギ
ーの一部を放出することにより、Ｑスイッチパルスの第
１パルスの発振に寄与する反転分布量を低くおさえ、第
１パルスの尖頭値を抑制して尖頭値のほぼ一定なＱスイ
ッチパルス列を得ることを特徴とするＱスイ、チレーザ
装置の駆動方法。Continuously pumped solid-state laser using acousto-optic Q-switching method,
When oscillating a Q-switch pulse, immediately before the Q-switch pulse is generated, the loss applied to the Q-switch is reduced to 6
1) By causing weak continuous oscillation and releasing part of the saturated population inversion energy, the amount of population inversion that contributes to the oscillation of the first pulse of the Q-switch pulse is kept low, and the peak value of the first pulse is suppressed. A method for driving a Q-switch/chill laser device, characterized by obtaining a Q-switch pulse train with a substantially constant peak value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56178031A JPS5879788A (en) | 1981-11-06 | 1981-11-06 | Driving method for q-switching laser device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56178031A JPS5879788A (en) | 1981-11-06 | 1981-11-06 | Driving method for q-switching laser device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5879788A true JPS5879788A (en) | 1983-05-13 |
| JPS6330791B2 JPS6330791B2 (en) | 1988-06-21 |
Family
ID=16041374
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56178031A Granted JPS5879788A (en) | 1981-11-06 | 1981-11-06 | Driving method for q-switching laser device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5879788A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4947023A (en) * | 1987-02-24 | 1990-08-07 | Nippon Steel Corporation | Method and apparatus for roll dulling by pulse laser beam |
| EP0918383A2 (en) * | 1997-10-24 | 1999-05-26 | Coherent Lübeck GmbH | Pulse laser with first pulse control |
| EP1162706A3 (en) * | 2000-06-06 | 2004-09-22 | Matsushita Electric Industrial Co., Ltd. | Q-switched frequency converted laser |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4270228B2 (en) * | 2006-06-19 | 2009-05-27 | パナソニック株式会社 | LASER DEVICE, ITS CONTROL METHOD, LASER PROCESSING METHOD USING THE SAME, AND LASER MACHINE |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5416200A (en) * | 1977-05-03 | 1979-02-06 | Boc Ltd | Laser |
| JPS56152288A (en) * | 1980-03-28 | 1981-11-25 | Erekutoro Saienteifuitsuku Ind | Q switching laser unit |
-
1981
- 1981-11-06 JP JP56178031A patent/JPS5879788A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5416200A (en) * | 1977-05-03 | 1979-02-06 | Boc Ltd | Laser |
| JPS56152288A (en) * | 1980-03-28 | 1981-11-25 | Erekutoro Saienteifuitsuku Ind | Q switching laser unit |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4947023A (en) * | 1987-02-24 | 1990-08-07 | Nippon Steel Corporation | Method and apparatus for roll dulling by pulse laser beam |
| EP0918383A2 (en) * | 1997-10-24 | 1999-05-26 | Coherent Lübeck GmbH | Pulse laser with first pulse control |
| EP0918383A3 (en) * | 1997-10-24 | 2001-03-21 | Coherent Lübeck GmbH | Pulse laser with first pulse control |
| EP1162706A3 (en) * | 2000-06-06 | 2004-09-22 | Matsushita Electric Industrial Co., Ltd. | Q-switched frequency converted laser |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6330791B2 (en) | 1988-06-21 |
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