GB2266406A - High power laser source - Google Patents
High power laser source Download PDFInfo
- Publication number
- GB2266406A GB2266406A GB9011987A GB9011987A GB2266406A GB 2266406 A GB2266406 A GB 2266406A GB 9011987 A GB9011987 A GB 9011987A GB 9011987 A GB9011987 A GB 9011987A GB 2266406 A GB2266406 A GB 2266406A
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- Prior art keywords
- laser source
- pump
- compressed
- power
- power laser
- Prior art date
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- 238000001069 Raman spectroscopy Methods 0.000 claims abstract description 23
- 230000000694 effects Effects 0.000 claims abstract description 11
- 239000007789 gas Substances 0.000 claims description 48
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 12
- 230000003287 optical effect Effects 0.000 claims description 10
- 229910052779 Neodymium Inorganic materials 0.000 claims description 7
- QEFYFXOXNSNQGX-UHFFFAOYSA-N neodymium atom Chemical compound [Nd] QEFYFXOXNSNQGX-UHFFFAOYSA-N 0.000 claims description 7
- 229910052689 Holmium Inorganic materials 0.000 claims description 6
- KJZYNXUDTRRSPN-UHFFFAOYSA-N holmium atom Chemical compound [Ho] KJZYNXUDTRRSPN-UHFFFAOYSA-N 0.000 claims description 6
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 3
- 239000001257 hydrogen Substances 0.000 claims description 3
- 229910052739 hydrogen Inorganic materials 0.000 claims description 3
- 229910052716 thallium Inorganic materials 0.000 claims description 3
- BKVIYDNLLOSFOA-UHFFFAOYSA-N thallium Chemical compound [Tl] BKVIYDNLLOSFOA-UHFFFAOYSA-N 0.000 claims description 3
- 229940105963 yttrium fluoride Drugs 0.000 claims description 3
- RBORBHYCVONNJH-UHFFFAOYSA-K yttrium(iii) fluoride Chemical compound F[Y](F)F RBORBHYCVONNJH-UHFFFAOYSA-K 0.000 claims description 3
- 239000002223 garnet Substances 0.000 claims 4
- 229910052727 yttrium Inorganic materials 0.000 claims 4
- VWQVUPCCIRVNHF-UHFFFAOYSA-N yttrium atom Chemical compound [Y] VWQVUPCCIRVNHF-UHFFFAOYSA-N 0.000 claims 4
- 238000012546 transfer Methods 0.000 description 14
- 238000000034 method Methods 0.000 description 9
- 230000008569 process Effects 0.000 description 8
- 230000003595 spectral effect Effects 0.000 description 8
- 230000008901 benefit Effects 0.000 description 5
- 230000005540 biological transmission Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- 230000009021 linear effect Effects 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 4
- 230000003321 amplification Effects 0.000 description 3
- 238000009826 distribution Methods 0.000 description 3
- 239000011159 matrix material Substances 0.000 description 3
- 238000003199 nucleic acid amplification method Methods 0.000 description 3
- 238000010521 absorption reaction Methods 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 230000000977 initiatory effect Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 229910052761 rare earth metal Inorganic materials 0.000 description 2
- 150000002910 rare earth metals Chemical class 0.000 description 2
- 101000804902 Drosophila melanogaster Xaa-Pro aminopeptidase ApepP Proteins 0.000 description 1
- 229910052691 Erbium Inorganic materials 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 239000002019 doping agent Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000009022 nonlinear effect Effects 0.000 description 1
- 239000013307 optical fiber Substances 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 230000002269 spontaneous effect Effects 0.000 description 1
- 230000002123 temporal effect Effects 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
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
- H01S3/30—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range using scattering effects, e.g. stimulated Brillouin or Raman effects
- H01S3/305—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range using scattering effects, e.g. stimulated Brillouin or Raman effects in a gas
-
- 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
- H01S3/108—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 non-linear optical devices, e.g. exhibiting Brillouin or Raman scattering
- H01S3/1086—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 non-linear optical devices, e.g. exhibiting Brillouin or Raman scattering using scattering effects, e.g. Raman or Brillouin effect
Abstract
A high-power laser source 1, is disclosed which allows a shift of the wavelength of the emitted beam. The device 1 includes a laser emitting a pump beam Fp of predetermined wavelength to a compressed-gas cell 2, that emits through Raman effect an output beam Fs at a Stokes wavelength. A diode 3 emits a control beam Fc with the same wave-length as the output beam Fs, and colinear with said pump beam Fp, which allows one to obtain a high-power output signal. <IMAGE>
Description
2266406 -1 High-power laser source The present invention relates to a
high-power laser source, and particularly to a high-power laser source emitting at a wavelength non dangerous for the human eye.
The field covered by the present invention relates to the implementation of high-power laser sources operating in the Following spectral windows: 1.06 pm and/or 1.54 pm, 1.396 pm, and 2.335 pm.
The choice of the emission wavelength in the spectral region located about 1.5 pm is related to the fact that the risk of ocular opical damage is minimized and that, at this wavelength, the atmosphere exhibits a good transmission window. Let us recall that the maximum acceptable exposure of the human eye is 5 pJ/co? at 1.064 pm, and jumps to 1 J/crd at 1.54 p M. This results in the implementation of high- power laser sources in this spectral region having unquestionable advantages.
However, there are no matrix and rare-earth materials exxibiting usable laser transmission properties, except the erbium ion.
The disadvantage associated with the use of this rare earth is that laser operation is described by a three-level system, which has a few disadvantages (high threshold, the laser transition is superimposed on an absorption band, easier saturation of the gain, etc.).
Another approach consists in implementing such a source by Raman transfer. In this case, there is used a Nd-YAG laser (neodymium- doped YAG laser) which pumps a cell in which is a gas which exhibits a Raman frequency shift permitting the transfer of the pump wave at 1.964 pm to 1.54 pm. Such a gas may be high-pressure methang (CH 4).
This gas has a Raman spectral shift of 2916 cm and a Ra man gain coefficient of about 1.4 cm/GW under a pressure of atmospheres.
Thus, w! Vt a pumping centered on the emission wavelength of the Nd-YAG laser, it is possible to generate an emission at the Stakes wavelength A S 2TX/W S derived from the rela tionship W S W p - W R$ where W p 3 W RY W S are the pump angular frequency, the Raman Frequency shift and the frequency of the Stokes wave, respec- tively. For the wavelength and for a given Raman shift in cm we obtain As = (i/A p (cm) - 2916 cm- However, such a source does not allow to deliver a beam at the Stakes wavelength optimized in conversion efficiency since the Raman process starts from a noise.
The present invention consequently implements such a source and provides means allowing to control an energy transfer from the pump wave to the emitted wave.
According to the present invention there is provided a high-power laser source comprising:
- a pump laser source emitting a pump beam (F p) with a predetermined wavelength (i p); - a compressed-gas cell receiving the pump beam F p and emit ting through Raman effect an output beam F with a so-called Stokes wavelength S; - a control light source transmitting a control beam F c to the gas cell, this control beam having a wavelength substan tially equal to that of the Stokes wave S The various features and advantages of the present inven tion will become apparent from the following detailed descrip tion of preferred embodiments given as a non-limitative exam ple with reference to the accompanying drawings, in which:
- Figure 1 shows a first device in which the present inven tion is embodled; - Figure 2 shows a second device in which the present inven tion is embodied; - Figures 3 through 5 show various means, in which the present invention is embodied, for combining the pump beam and the control beam in the gas cell; - Figures 6 and 7 are diagrams of emission optical power; - Figure 8 is a diagram describing the time-distributed opti cal power of a device in which the invention is embodied; and - Figure 9 is an embodiment of a variant of the device in which the invention is embodied.
Referring to Figure 1, a description will first be given of a first embodiment of the high-power laser device.
The device in F igure 1 comprises essentially:
- a laser rod with-an external cavity 1 emitting a pump beam F p at a predetermined wave-length p; - a trigger, called a "Q switch", allowing to operate the la ser in the Q-switched mode; - a compressed-gas cell 2 receiving the pump beam F p and whose gas is excited by this-beam in such a manner that it emits by Raman effect a beam F S with a frequency shift and that the re is an energy transfer from the pump beam F p to the beam F S; - a control light source such that a laser diode 3 controlled by a circuit 4 and emitting toward the gas cell 2 a control beam F c at a wavelength substantially equal to that of the beam F; and - two mirrors M1 and M2 disposed on either side of the laser 1 and of the gas cell 2, and forming an optical cavity.
The laser.rod 1 allows to implement a high-power laser emitting at a wavelength p dangerous for the human eye. This type of laser is common in technology due to the high power it is capable of emitting. For example, it can be a neodymium doped YAG (Ne-YAG) laser emitting at a wavelength p = 1.064 micrometers.
The compressed-gas cell 2 contains a gas such as methane CH 4 allowing to obtain from a pump beam F p with a wavelength A p = 1.064 pm, a beam F S of wavelength S = 1.54 pm.
The laser diode 3 emits a control beam F c with a wavelength substantially equal to the wavelength A S = 1.54 vm. The con trol beam F c and the pump beam F p enter the gas cell 2 in a substantially colinear manner through a transparent side 20 of the gas cell 2. They pass through the gas cell 2 along a main axis of the cell and leave it through a transparent side 21 opposite to the side 20. The beam F S leaving the gas cell 2 reaches the mirror M1 where it is reflected, and travels back to the mirror M2. Thus, the cavity formed by the mirrors M1 and M2 allows to take advantage of the high power density in side the cavity and, through the multiple travels in the cavi ty, to achieve a conversion efficiency.
In the compressed-gas cell, the evolution process of the Raman wave can be represented by the following relationship p p 0 exp(-a x L 0 /A L (1) S S S +9R x PP eff x eff variable Under low-conversion conditions and corresponding to the case where the non-linear process takes place. The va rious parameters denote:
a S: absorption coefficient at w S; L: propagation distance in the gas cell 2; -9R: Raman gain coefficient of the gaseous medium in the gas cell 2; p 0: pump power incident an the gas cell 2; p A effective area on which the non-linear effect takes e f f place; L eff effective length of the non-linear interaction taking into account the loss due to the pump wavelength; p S: power of the Stokes wave as a function of the propa gation distance in the gas cell 2; p 0: represents in this case the incident power initiating S the non-linear process.
In the absence of a control beam injected at the Stokes wavelength, the transfer mechanism is generated from the noi se in the cavity and by amplification of the spontaneous Sto les photons present in the cavity.
This power P 0 can be controlled. To this end, the control S beam F at the Stokes wavelength 11 is injected in the cavity c S and is amplified.
A laser diode 3 of the InGaAsP type producing the control beam F c permits to-:control the process of energy transfer from the pump wave (Nd-YAG laser)to the signal wave F. To this S end, it is sufficient to couple to the Raman laser oscillator a wave from the laser diode with the same frequency as that of the Stakes wave and denoted by the term P 0 in the relation s ship (1).
Referring to Figure 2, there is shown a second embodiment in which the optical cavity delimited by the mirrors M1 and M2 contains the laser 1 but does not contain the.gas cell 2. The latter is located in the path of the pump beam F P, but outside the optical cavity, and the Raman amplification in the gas cell 2 is therefore implemented from outside the active me dium.
This disposition allows to make the control beam F c stric tly colinear with the pump beam F P without having to fear an optical return an the laser diode 3, which might be the case in the device of Figure 1 if the control beam F c and pump beam F P were strictly colinear.
The coincidence of the control beam F c and the pump beam F P can be obtained, as shown in Figures 2 and 3, by means of a separating plate disposed in the paths of the pump beam F P and control beam F c and suitably oriented with respect to the se beams.
The control beam F c can thus be injected by using the re flection on the side of the laser crystal 1 cut to the Brew ster angle for the pump wavelength (see Figure 4).
Another coupling type consists in employing a singlemode optical fiber 5 retaining its polarization (Figure 5). At the end of the latter is an optics that allows to adjust the size of the beam to that of the cavity mode in the gas cell 2.
Referring now tri Figures 6 and 7, there is shown the trend of the Stokes power as a function of the propagation distance 7 - or of the amplitude of the signal injected with a constant peak pump power.
Figure 6 shows the Stokes power at various points of the gas cell for a pump beam with a peak power P 0 =_2 MW and a P wavelength( 1.064 pm, and for a control beam with a very low power P c 1 PW), and even without a control beam. It can be seen from this Figure that for a 20-cm long gas cell, the Stokes signal cannot be detected for a 8-cm path in the cell, and that at the output of the cell (20-cm path), the Stokes signal is still very low. The transfer.of energy at the output of the gas cell has consequently been insignifi cant.
On the other hand, Figure 7 shows the operation of a device. with a control beam F c with a power PO = 1 mW and a wavelength A = 1.54 pm. The pump beam has, S a = S as previously, a power P P 2 MW and a wavelength 1 P = 1.06.m.
One can see in this Figure 7 the effect of control and initialization of the process of transfer of the pump power to the Stokes wave. For a 4-cm path in the gas cell, a Stokes wave is already detectable. For a 20-cm path in the cell, one can see a Stokes wave with a power of substantially 0.4 MW.
A transfer of power from the pump wave to the Stokes wave has consequently substantially occured. In this example, the pump wave has Gaussian temporal and spatial profiles.
In the low-transfer approximation, the gain varies linear ly with the pump power and we may write, disregarding the ab sorption, that the energy of the Stokes pulse fall -ows a law of the type:
E E 0 + x L, rf PO/AP P 0 /A S dx dy dt, S S 1 9R p eff s eff where AJ represents the effective areas of the pump and Ra eff man beams, respectively, and E 0 is the energy injected into S the cavity.
- 8 The transferred energy will be at a maximum when the ef fective areas of the pump beam and the Raman beam are matched (identical areas and profileg). In a cavity of the semi-confo cal type, it is possible to dispose the gas cell in a suita ble location in order to satisfy this condition. What remains then is only to optimize the spatial distribution of the am plitude of the signal tave from the laser diode.
The external control makes it possible to implement a pul sed source with a more stable peak power and a more reproduci ble operation from a cycle to the next.
Referring to Figure 8, there are shown diagrams of time dis tribution for the various beams (pump beam, control beam, out put beam).
The tipper diagram in Figure 8 shows a pulse of the pump beam F p having a Gaussian profile.
Upon the transmission of this pulse F p, pulses of the con trol beam F 0 through F n are transmitted.
c c There are then obtained, as shown in the lower diagram in Figure 8, output pulses F 0 through F n corresponding to the S S pulses F 0 through F n and resulting from transfers of energy c c from the pump beam.
The pulse-type profile of the output beam results, there fore, from the pulse-type profile of the control beam. It is consequently possible to position the output pulses as desired with respect to each other.
Such a possibility contributes thus to achieve a laser system allowing to generate pulse trains controllable by the laser diode 3 and reconfigurable from a round to the next, and making possible the use of signal processing techniques.
By way of example, the pump pulse may have a duration of to 20 ns, for example, and the control pulses (and conse quently, the output pulses) a duration of about 1 ns.
Moreover, the position of the control pulses with respect' to the Gaussian pEdfile of the pump pulse allows to obtain output pulses of more or les=s high amplitude. Thus it is pos sible to modulate the power transmitted by the output beam.
This allows, for example in a detection system, to match the transmitting power to the distance of the object to be detec ted so as to avoid dazzling the detection system by an exces sive power received back from the object.
In the foregoing, the Field being covered includes the high-powet lasers operating in the 1.5-pm window, this wave length being obtained through the stimulated Raman effect.
The pump laser is a high-power Nd-YAG laser capable of being pumped by laser diodes. In the cavity of the laser, a cell filled with a high-pressure gas is disposed. Through sti mulated Raman effect, a transfer of power from the pump wave to the Stokes wave is observed, the frequency shift being go verned by the spectral properties of the Raman gain curve of the non-linear medium.
In general, the transfer is obtained from the amplifica tion of a noise at the Stokes frequency, where the medium ex hibits a resonance line. In this case, the spectral properties of the Stokes wave being emitted are directly related to the selectivity of a resonator or of the cavity.
In another embodiment of the present invention, the laser diode 3 is replaced by a laser source 41 pumped by a laser diode 42. Such a configuration is shown in Figure 9.
This embodiment is particularly suitable to the transmis sion of high-power beams of various wavelengths.
Thus it is possible to use for the pump laser 1 a power source based on yttrium fluoride (LiYF 4) doped with holmium (Ho 3+), referred to as Ho-Y1.F. The transmitting wavelength of such a source is 1.396 pm. The gas cell 2 is based an high- - 10 pressure methane (CH 4). A pump beam F p emitted by the pump laser 1 produces, Chrough Raman effect, the emission of a Sto kes wave of 2.355-pm wavele.ngth. For the control source 4, the chosen source 41 is based on a YALG 3 matrix doped with thallium that can be referred to as Tm-YALO 3_ Cr 3+, where Cr 3+ is a Co dopant. This laser source can be pumped longitudinally by a laser diode emitting a wave between 0.71 and 0.8 pm. The control beam F c has then a wavelength of about 2.355 pm. There is thus achieved a control capability of the Raman effect in the gas cell 2.
The wave obtained through Raman effect has the advantage of being included in a spectral region corresponding to a transmission window of the atmosphere. Such a combination al lows thus to implement a high-power source at 2.355 pm.
Another embodiment uses a Nd-YAG laser emitting at 1.3187 pm and a Ramarl cell filled with high-pressure hydrogen emitting a Stokes wave at a wavelength A S = 2.916991 pm.
The laser source 41 is then a source based on a matrix of YA10 3 doped with holmium (referred to as Ho-YA10 3). This source 41 excited by a laser diode emits at a wavelength p of about 2.918 pm.
The adjustment of the two wavelengths ( p and is per- formed through control of the composition of the gas in the gas cell (pressure, temperature, mixing ratio, etc.) and of the parameters of the laser cavity of the Ho-YA10 3 crystal.
Aspects of the present invention include a mode of control of the initiation of the process of emission of the Stokes wave by an external source. The control of this transfer is achieved by means of a laser diode. The photons from this diode are coupled through a reflection with the cavity. A synchronization of the triggering of the Nd-YAG laser and of the laser diode allows to oDtimize the conversion efficiency.
- -j 1 - Using a laser diode has certain advantages, in particular in the vicinity of 1.5 pm since there are single-frequency DFB-type source allowing to inject in the amplifying medium (consisting of the Nd-YAG laser and the gas cell, or of the cell alone) a signal wave with a narrow spectral width that will trigger the process of Raman stimulated emission. Fur thermore, the qualities of the beam are improved through con trol of the spatial distribution of the control beam (i.e., of the laser diode and the associated beam processing optics).
The possible applications of the present invention cover the implementation of laser illumination and range-finding systems.
The various objects and features which have been described are only non-limitative examples, and many modifications and variations are possible without departing from the basic prin ciples of the present invention. Also, the numerical examples and the examples of materials capable of being used have been given only to illustrate the description of the invention.
Claims (9)
1. A high-power laser source, comprising - a pump laser source e mitting a pump beam of predetermined wavelength; - a compressed-gas cell receiving said pump beam and emitting through Raman effect an output beam with a wavelength refer10 red to as a Stokes wave; and - a control light source transmitting a control beam to said gas cell, said control beam having a wavelength substantially equal to said Stokes wave. 15
2. A high- power laser source according to claim 1, wherein said pump bea and said control beam are substantially calinear.
3. A high-power laser source according to claim 2, wherein 20 said pump beam and said control beam enter said compressed-gas cel through the same side.
4. A high-power laser source according to claim 3, wherein said pump laser source and said compressed-gas cell are com25 prised in an optical cavity formed by two reflecting means.
5. A high-power laser source according to claim 3, wherein only said pump laser source is comprised in an optical cavity formed by two reflecting means. 30
6. A high-power laser source according to claim 1, wherein said pump laser source is based on neodymium.
7. A high-power laser source according to claim 1, wherein said compressed-gas cell contains methane (CH 4).
8. A high-power laser source according to claim-7, wherein said control light source is a laser diode of the InGaAsP type.
9. A high-power laser source according to claim6, wherein:
- said pump laser source is an yttrium garnet doped with neo dymium (Nd-YAG); - said compressed-gas cell contains compressed hydrogen; and said control light source comprises a source based on YA10 3 doped with holmium and pumped by a laser diode.
lo. A high power laser source substantially as hereinbefore described with reference to the accompanying drawings and as shown in figure 1 or figure 2 or figure 9 of those drawings.
9. A high-power laser source according to claim 1, wherein said control light source comprises a laser source pumped by a laser diode.
10. A high-power laser source according to claim 7, wherein said pump laser source is a laser source based on yttrium gar net doped with neodymium (Nd-YAG).
11. A high-power laser source according to claim 9, wherein:
- said pump laser source is based on yttrium fluoride doped with holmium (Ho 3+_ LiYF 4); - said compressed-gas cell uses compressed methane (CH 4); and - said control light source comprises a source based on YA10 3 doped with thallium and pumped by a laser diode.
12. A high-power laser source according to claim 9, wherein:
- said pump laser source is an yttrium garnet doped with neo dymium (Nd-YAG); - said compressed-gas cell contains compressed hydrogen; and said control light source comprises a source based on YA10 3 doped with holmium and pumped by a laser diode.
13. A high power laser source substantially as hereinbefore described with reference to the accompanying drawings and as shown in figure 1 or figure 2 or figure 9 of those drawings.
- 14._ Amendments to the claims have been filed as follows 1. A high-power laser source, comprising 7 a pump laser source emitting a pump beam of predetermined wavelength; - a compressed-gas cell receiving said pump beam and emitting through Raman effect an output beam with a wavelength refer10 red to as a Stokes wave; and - a control light source transmitting a control beam to said gas cell, said control beam having a wavelength substantially equal to said Stokes wave, - wherein said pump beam and said control beam are substantially colinear and enter said compressed-gas cell 15 through the same side, and said pump laser source and said compressedgas cell are comprised in an optical cavity formed by two reflecting- means. 20 2. A high-power laser source according to claim 1, wherein only said pump laser source is comprised in an optical cavity formed by two reflecting means.
3. A high-power laser source according to claim 1, wherein said pump laser.souree is based on neodymium.
- ly- 4. A high-power laser source according to claim 1, wherein said compressed-gas cEdl contains methane (CH 4 5. A high-power laser source according to claim 4, wherein said control light source is a laser diode oF the InGaAsP t y p e 6. A high-power laser source according to claiml, wherein said control light source comprises a laser source pumped by a laser diode.
7. A high-power laser source according to claim 4, wherein said pump laser source is a laser source based on yttrium gar net doped with neodymium (Nd-YAG).
8. A high-power- laser source according to claim 6, wherein:
- said pump laser source is based on yttrium Fluoride doped with holmium (Ho 3+_ LUF 4); - said compressed-gas cell uses compressed methane (CH 4); and - said control light source comprises a source based on YA10 3 doped with thallium and pumped by a laser diode.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR8907078A FR2691588B1 (en) | 1989-05-30 | 1989-05-30 | Power laser source. |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB9011987D0 GB9011987D0 (en) | 1993-07-14 |
| GB2266406A true GB2266406A (en) | 1993-10-27 |
| GB2266406B GB2266406B (en) | 1994-03-16 |
Family
ID=9382149
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9011987A Expired - Fee Related GB2266406B (en) | 1989-05-30 | 1990-05-30 | High-power laser source |
Country Status (5)
| Country | Link |
|---|---|
| DE (1) | DE4016631A1 (en) |
| FR (1) | FR2691588B1 (en) |
| GB (1) | GB2266406B (en) |
| IT (1) | IT1239621B (en) |
| SE (1) | SE9001903D0 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9609732B2 (en) | 2006-03-31 | 2017-03-28 | Energetiq Technology, Inc. | Laser-driven light source for generating light from a plasma in an pressurized chamber |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2033141A (en) * | 1978-10-03 | 1980-05-14 | Us Energy | Laser amplifiers |
| GB2034962A (en) * | 1978-11-03 | 1980-06-11 | Us Energy | Lasers |
| GB2076215A (en) * | 1980-05-16 | 1981-11-25 | Centre Nat Rech Scient | Process and device for delivering a monochromatic light beam by stimulated scattering |
| EP0063205A1 (en) * | 1981-04-11 | 1982-10-27 | ELTRO GmbH Gesellschaft für Strahlungstechnik | Laser system |
| GB2136194A (en) * | 1983-03-08 | 1984-09-12 | Us Energy | Raman laser |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4327337A (en) * | 1980-01-03 | 1982-04-27 | General Electric Company | Intracavity raman frequency conversion in a high power laser |
-
1989
- 1989-05-30 FR FR8907078A patent/FR2691588B1/en not_active Expired - Fee Related
-
1990
- 1990-05-18 IT IT47972A patent/IT1239621B/en active IP Right Grant
- 1990-05-23 DE DE4016631A patent/DE4016631A1/en not_active Withdrawn
- 1990-05-25 SE SE9001903A patent/SE9001903D0/en unknown
- 1990-05-30 GB GB9011987A patent/GB2266406B/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2033141A (en) * | 1978-10-03 | 1980-05-14 | Us Energy | Laser amplifiers |
| GB2034962A (en) * | 1978-11-03 | 1980-06-11 | Us Energy | Lasers |
| GB2076215A (en) * | 1980-05-16 | 1981-11-25 | Centre Nat Rech Scient | Process and device for delivering a monochromatic light beam by stimulated scattering |
| EP0063205A1 (en) * | 1981-04-11 | 1982-10-27 | ELTRO GmbH Gesellschaft für Strahlungstechnik | Laser system |
| GB2136194A (en) * | 1983-03-08 | 1984-09-12 | Us Energy | Raman laser |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9609732B2 (en) | 2006-03-31 | 2017-03-28 | Energetiq Technology, Inc. | Laser-driven light source for generating light from a plasma in an pressurized chamber |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2691588B1 (en) | 1994-12-30 |
| IT9047972A1 (en) | 1991-11-18 |
| GB2266406B (en) | 1994-03-16 |
| IT9047972A0 (en) | 1990-05-18 |
| IT1239621B (en) | 1993-11-11 |
| DE4016631A1 (en) | 1993-11-25 |
| FR2691588A1 (en) | 1993-11-26 |
| SE9001903D0 (en) | 1990-05-25 |
| GB9011987D0 (en) | 1993-07-14 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19980530 |