JPH04175616A - Laser beam monitoring device - Google Patents
Laser beam monitoring deviceInfo
- Publication number
- JPH04175616A JPH04175616A JP30221990A JP30221990A JPH04175616A JP H04175616 A JPH04175616 A JP H04175616A JP 30221990 A JP30221990 A JP 30221990A JP 30221990 A JP30221990 A JP 30221990A JP H04175616 A JPH04175616 A JP H04175616A
- Authority
- JP
- Japan
- Prior art keywords
- laser beam
- amplifier
- laser
- gain
- temperature
- 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.)
- Pending
Links
- 238000012806 monitoring device Methods 0.000 title claims description 10
- 238000001514 detection method Methods 0.000 claims abstract description 20
- 239000006096 absorbing agent Substances 0.000 claims description 4
- 238000010521 absorption reaction Methods 0.000 abstract description 13
- 230000007423 decrease Effects 0.000 abstract description 6
- 230000002238 attenuated effect Effects 0.000 abstract description 2
- 230000003287 optical effect Effects 0.000 abstract description 2
- 238000010438 heat treatment Methods 0.000 abstract 1
- 238000005259 measurement Methods 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 7
- 230000020169 heat generation Effects 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- 230000003321 amplification Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
Abstract
Description
【発明の詳細な説明】
Ｃ産業上の利用分野〕
本発明はレーザ光モニタ装置に関し、特にレーザ光波長
が近赤外域にある高出力固体レーザのレーザ光の強度を
モニタするレーザ光モニタ装置に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a laser beam monitoring device, and more particularly to a laser beam monitoring device that monitors the intensity of laser beam of a high-power solid-state laser whose laser beam wavelength is in the near-infrared region. .
従来、この種のレーザ光の強度のモニタ装置は、第５図
に示すように、レーザ発振器１の全反射ミラー１２から
のレーザ光の一部の漏れ光を適当なフィルタ３により減
衰して検出器５にレーザ光を入射するものか、あるいは
第６図に示すように、出射側のレーザ光路にビームスプ
リッタ４を設置しレーザ光の一部を取り出し、適当なフ
ィルタ３により、第５図と同様に、レーザ光を減衰して
検出器５にレーザ光を入射することによりレーザ光強度
を相対的に検出するというものであった。Conventionally, this type of laser light intensity monitoring device detects a portion of the laser light leaked from the total reflection mirror 12 of the laser oscillator 1 by attenuating it with an appropriate filter 3, as shown in FIG. Either a beam splitter 4 is installed in the laser beam path on the output side to take out a part of the laser beam, and an appropriate filter 3 is used to input the laser beam into the device 5, or as shown in FIG. Similarly, the intensity of the laser light is relatively detected by attenuating the laser light and making the laser light enter the detector 5.
レーザ光強度は、半導体型の検出器により検出され、信
号は増幅されて処理されるというものであった。The laser light intensity was detected by a semiconductor type detector, and the signal was amplified and processed.
上述した従来のレーザ光モニタ装置は、レーザ光の波長
が近赤外域にある場合、半導体である検出素子のレーザ
光吸収による発熱により検出感度の温度ドリフトや、レ
ーザ光強度が非常に大きいため、ミラーやフィルタの各
部分がレーザ光吸収により発熱し、その特性が温度によ
りドリフトすることにより長時間にわたりレーザ出力を
測定した場合、モニタの出力値の変動があられれるとい
う欠点があった。In the conventional laser beam monitoring device described above, when the wavelength of the laser beam is in the near-infrared region, there is a temperature drift in the detection sensitivity due to heat generation due to the absorption of the laser beam by the semiconductor detection element, and the laser beam intensity is extremely large. Each part of the mirror and filter generates heat due to absorption of laser light, and its characteristics drift with temperature, resulting in fluctuations in the output value of the monitor when measuring the laser output over a long period of time.
本発明のレーザ光モニタ装置は、レーザ光のエネルギを
吸収する吸収体と、
前記吸収体に伝熱接触し温度により抵抗値が変化する感
温抵抗素子と、
前記レーザ光の強度を検出し検出信号を出力する検出素
子と、
前記感温抵抗素子の抵抗値により利得が設定される利得
設定回路を有し前記検出信号を増幅する増幅器とを有す
るものである。The laser beam monitoring device of the present invention includes: an absorber that absorbs the energy of the laser beam; a temperature-sensitive resistance element that is in heat transfer contact with the absorber and whose resistance value changes depending on temperature; and detects and detects the intensity of the laser beam. The device includes a detection element that outputs a signal, and an amplifier that amplifies the detection signal and has a gain setting circuit whose gain is set according to the resistance value of the temperature-sensitive resistance element.
次に本発明について図面を参照して説明する。 Next, the present invention will be explained with reference to the drawings.
第１図は本発明の一実施例を示すブロック図である。FIG. 1 is a block diagram showing one embodiment of the present invention.
第１図において、本発明のレーザ光モニタ装置は、レー
ザ発振器１と、モニタ回路２とがら構成されている。In FIG. 1, the laser beam monitoring device of the present invention is composed of a laser oscillator 1 and a monitor circuit 2. As shown in FIG.
レーザ発振器１は、レーザ媒質１１と、全反射ミラー１
２と、出射側ミラー１３とにより構成されている。The laser oscillator 1 includes a laser medium 11 and a total reflection mirror 1.
2 and an exit side mirror 13.
モニタ回路２は、ビームスプリッタ２１．２２と、フィ
ルタ２３と、検出素子２４と、増幅器２５と、吸収板２
６と、増幅器２５の利得を決定する負帰還抵抗である抵
抗２７とから構成されている。The monitor circuit 2 includes beam splitters 21 and 22, a filter 23, a detection element 24, an amplifier 25, and an absorption plate 2.
6, and a resistor 27 which is a negative feedback resistor that determines the gain of the amplifier 25.
また、抵抗２７は、温度が上昇するほど抵抗値が低くな
る、たとえば、サーミスタ等の負性抵抗素子であり、吸
収板２６に接触して取付けである。Further, the resistor 27 is a negative resistance element such as a thermistor, whose resistance value decreases as the temperature rises, and is attached in contact with the absorption plate 26.
次に、本実施例の動作について説明する。Next, the operation of this embodiment will be explained.
レーザ発振器１より出射したレーザ光はモニタ回路のビ
ームスプリッタ２１により１％反射され、さらに他のビ
ームスブリ・ンタ２２により９９％と１％に分離される
。1% of the laser light emitted from the laser oscillator 1 is reflected by a beam splitter 21 of a monitor circuit, and further separated into 99% and 1% by another beam splitter 22.
この反射された１％のレーザ光はフィルタ２３により減
衰された後、検出素子２４に入射し、検出信号は増幅器
２５により増幅される。このとき、増幅器２５の利得を
決定する抵抗２７は、前述のように、９９％のレーザ光
を吸収する吸収板２６に接触して取付けであるので、吸
収板２６の温度上昇によりその抵抗値を低下するよう変
化させる。This reflected 1% laser light is attenuated by the filter 23 and then enters the detection element 24, and the detection signal is amplified by the amplifier 25. At this time, as mentioned above, the resistor 27 that determines the gain of the amplifier 25 is attached in contact with the absorption plate 26, which absorbs 99% of the laser beam, so the resistance value decreases due to the temperature rise of the absorption plate 26. change to decrease.
第２図は一定出力のレーザ光が照射した時の時間ｔの経
過にともない温度上昇する検出素子２４の出力信号の変
化の様子を示す。FIG. 2 shows how the output signal of the detection element 24 changes as the temperature rises with the passage of time t when irradiated with a laser beam of constant output.
第３図は、時間ｔの経過とともにレーザ光の吸収による
吸収板２６の温度上昇によって抵抗２７の抵抗値が上昇
し、増幅器２５の利得が低下する様子を示す。FIG. 3 shows how the resistance value of the resistor 27 increases and the gain of the amplifier 25 decreases as the temperature of the absorption plate 26 increases due to absorption of laser light as time t elapses.
第４図は、モニタ回路２の時間ｔの経過に対するモニタ
出力特性であり、第２図の時間出力特性の検出素子２４
の検出信号出力が、第３図の時間増幅度特性の増幅器２
５で補正される様子を示す。FIG. 4 shows the monitor output characteristics of the monitor circuit 2 over time t, and the detection element 24 of the time output characteristics shown in FIG.
The detection signal output of the amplifier 2 has the time amplification characteristic shown in Fig. 3.
5 shows how it is corrected.
以上説明したように本発明は、レーザ光による部分発熱
による光学部品や検出器の温度ドリフトを補正するため
長時間にわたって正確なレーザ光強度の測定が可能とな
るという効果がある。As described above, the present invention has the advantage that it is possible to accurately measure the laser light intensity over a long period of time because it corrects the temperature drift of optical components and detectors due to partial heat generation caused by the laser light.
第１図は本発明の一実施例を示すブロック図、第２図は
第１図に示した検出素子の時間経過に対する検出信号出
力を示す図、第３図は第１図に示した増幅器の時間経過
に対する利得の変化を示す図、第４図はモニタ回路の時
間経過に対するモニタ出力特性を示す図、第５図、第６
図は従来のレーザ光モニタ装置の一例を示すブロック図
である。
１・・・レーザ発振器、２・・・モニタ回路、３．２３
１６．フィルタ、４，２１．２２・・・ビームプリッタ
、５・・・検出器、１１・・・レーサ媒質、１２・・・
全反射ミラー、１３・・・出射側ミラー、２４・・・検
出素子、２５・・・増幅器、２６・・・吸収板、２７・
・・抵抗。FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing the detection signal output of the detection element shown in FIG. 1 over time, and FIG. 3 is a diagram showing the detection signal output of the detection element shown in FIG. Figure 4 shows the change in gain over time. Figure 4 is a diagram showing the monitor output characteristics of the monitor circuit over time. Figures 5 and 6 are diagrams showing the change in gain over time.
The figure is a block diagram showing an example of a conventional laser beam monitoring device. 1... Laser oscillator, 2... Monitor circuit, 3.23
16. Filter, 4, 21. 22... Beam splitter, 5... Detector, 11... Laser medium, 12...
Total reflection mirror, 13... Output side mirror, 24... Detection element, 25... Amplifier, 26... Absorption plate, 27...
··resistance.
Claims (1)
体に伝熱接触し温度により抵抗値が変化する感温抵抗素
子と、 前記レーザ光の強度を検出し検出信号を出力する検出素
子と、 前記感温抵抗素子の抵抗値により利得が設定される利得
設定回路を有し前記検出信号を増幅する増幅器とを有す
ることを特徴とするレーザ光モニタ装置。 ２、前記感温抵抗素子は負性抵抗素子であり、前記利得
設定回路は負帰還回路であることを特徴とする請求項１
記載のレーザ光モニタ装置。[Claims] 1. An absorber that absorbs the energy of the laser beam, a temperature-sensitive resistance element that is in heat transfer contact with the absorber and whose resistance value changes depending on temperature, and a detection signal that detects the intensity of the laser beam. A laser beam monitoring device comprising: a detection element that outputs a signal; and an amplifier that amplifies the detection signal and has a gain setting circuit whose gain is set according to the resistance value of the temperature-sensitive resistance element. 2. Claim 1, wherein the temperature-sensitive resistance element is a negative resistance element, and the gain setting circuit is a negative feedback circuit.
The laser light monitoring device described.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP30221990A JPH04175616A (en) | 1990-11-07 | 1990-11-07 | Laser beam monitoring device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP30221990A JPH04175616A (en) | 1990-11-07 | 1990-11-07 | Laser beam monitoring device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04175616A true JPH04175616A (en) | 1992-06-23 |
Family
ID=17906388
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP30221990A Pending JPH04175616A (en) | 1990-11-07 | 1990-11-07 | Laser beam monitoring device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04175616A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8406090B2 (en) | 2008-03-04 | 2013-03-26 | HGST Netherlands B.V. | Laser power sensor for thermally assisted magnetic recording |
-
1990
- 1990-11-07 JP JP30221990A patent/JPH04175616A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8406090B2 (en) | 2008-03-04 | 2013-03-26 | HGST Netherlands B.V. | Laser power sensor for thermally assisted magnetic recording |
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