EP1362394A1 - Amplificateur laser a gain eleve - Google Patents

Amplificateur laser a gain eleve

Info

Publication number
EP1362394A1
EP1362394A1 EP02704243A EP02704243A EP1362394A1 EP 1362394 A1 EP1362394 A1 EP 1362394A1 EP 02704243 A EP02704243 A EP 02704243A EP 02704243 A EP02704243 A EP 02704243A EP 1362394 A1 EP1362394 A1 EP 1362394A1
Authority
EP
European Patent Office
Prior art keywords
crystal
index
core
axis
sapphire
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.)
Withdrawn
Application number
EP02704243A
Other languages
German (de)
English (en)
Inventor
Hans W. Bruesselbach
Alexander A. Betin
David S. Sumida
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Raytheon Co
Original Assignee
Raytheon Co
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Raytheon Co filed Critical Raytheon Co
Publication of EP1362394A1 publication Critical patent/EP1362394A1/fr
Withdrawn legal-status Critical Current

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
    • H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
    • H01S3/06—Construction or shape of active medium
    • H01S3/0602—Crystal lasers or glass lasers
    • H01S3/0606—Crystal lasers or glass lasers with polygonal cross-section, e.g. slab, prism
    • 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
    • H01S3/02—Constructional details
    • H01S3/04—Arrangements for thermal management
    • H01S3/042—Arrangements for thermal management for solid state lasers
    • 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
    • H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
    • H01S3/06—Construction or shape of active medium
    • H01S3/0602—Crystal lasers or glass lasers
    • H01S3/0612—Non-homogeneous structure
    • 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
    • H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
    • H01S3/06—Construction or shape of active medium
    • H01S3/0602—Crystal lasers or glass lasers
    • H01S3/0615—Shape of end-face
    • 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
    • H01S3/14—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range characterised by the material used as the active medium
    • H01S3/16—Solid materials
    • H01S3/1601—Solid materials characterised by an active (lasing) ion
    • H01S3/1603—Solid materials characterised by an active (lasing) ion rare earth
    • H01S3/1618—Solid materials characterised by an active (lasing) ion rare earth ytterbium
    • 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
    • H01S3/14—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range characterised by the material used as the active medium
    • H01S3/16—Solid materials
    • H01S3/163—Solid materials characterised by a crystal matrix
    • H01S3/164—Solid materials characterised by a crystal matrix garnet
    • H01S3/1643—YAG

Definitions

  • the present invention relates to optical and other electromagnetic systems. More specifically, the present invention relates to high gain and high etendue optical amplifiers for use with lasers and other devices.
  • Optical amplifiers are used in many applications. Optical amplifiers are used as gain elements in lasers and in a number of other optical systems such as amplifiers per se in Master Oscillator Power Amplifiers (MOP s), the amplifying component of loop phase conjugator systems, and as the nonlinear medium in optical four-wave mixing devices. In these and other applications, high gain at large etendue is often the enabling and most important design consideration. Etendue is defined as the product of the cross-sectional area of a beam and its full angular extent.
  • MOP s Master Oscillator Power Amplifiers
  • Etendue is defined as the product of the cross-sectional area of a beam and its full angular extent.
  • optical amplifiers can be divided into two categories: guided and unguided.
  • unguided amplifiers etendue is maximized by adjusting the transverse-to-longitudinal dimension ratio, since the angular field of view of such an amplifier is, to within factors of order unity that depend on the details of the geometry, proportional to the transverse dimension divided by the length.
  • high gain and high etendue in these conventional, non-guided, optical amplifiers are inherently conflicting requirements. This is due to the fact that
  • the gain coefficient is directly proportional to the amplifier's length, the etendue is inversely proportional.
  • the gain of these conventional optical amplifiers is in textbook theories limited by amplified spontaneous emission, in practice it is typically limited by the onset of parasitic oscillations involving reflections from the boundaries of the gain medium or other nearby surfaces.
  • TIR total internal reflection
  • Fiber amplifiers also fall into the category of being guided amplifiers, but high-etendue devices have not been fabricated.
  • the performance of guided devices can also be limited by parasitic oscillation.
  • Recent art for example, uses a polished cylindrical rod as a light guide in an end-pumped optical amplifier (in this art the guiding was desired only for the pump, not the gain wavelength). The gain achievable from this device was reported to be limited, however, by parasitic oscillation around its circumference.
  • the inventive amplifier includes a first crystal with a first index of refraction and a second crystal bonded to the first crystal about an axis of propagation and having a second index of refraction.
  • the first index is slightly higher than the second index such that light through the first crystal is totally internally reflected.
  • the first crystal is a square-cross-sectioned parallelepiped of Yb:YAG, having, an index of refraction of approximately 1.82, and the second crystal is several pieces of sapphire with an index of approximately 1.78, surrounding the Yb:YAG. Light is guided along the long dimension of the parallelepiped.
  • the invention is, in its preferred embodiment, a light guide fabricated out of crystalline materials, diffusion bonded together. If the core of the light guide is doped with laser ions, high gain amplifiers made be designed and operable over a large etendue. With a judicious choice of the laser crystal and cladding materials, shape, and bonding technique, the guided amplifier is much less susceptible to parasitic oscillation than amplifiers constructed in accordance with the teachings of the present art.
  • the diffusion bonded structure guides both the lasing wavelength and the optical pumping beam, which may be supplied by a laser diode array.
  • the pumping beams may be guided by the cladding. In either case, this low loss guiding down a path several absorption depths long is conducive to efficient pumping, making possible high gain with quasi-three or four level ions, not achievable with the present art.
  • the purpose in configuring the gain medium as a light guide is to take advantage of the fact that the etendue then depends only on the guide's transverse size and numerical aperture, and not on its length. Therefore, the gain and etendue can both be increased.
  • the gain of practical optical amplifiers is limited by the onset of parasitic oscillation.
  • Large etendue makes guided amplifiers particularly susceptible to parasitic oscillation.
  • the present invention can better achieve high gain in a guided amplifier because, in the best implementations, it uses a polygonal (preferably square or rectangular) rather than a circular guide cross section.
  • the cladding refractive index is selected to limit the guide-to-cladding total internal reflection (TIR) angle to disallow parasitic modes.
  • broad band antireflection (AR) coatings and/or end caps are used to inhibit guide-end-reflection-involved modes.
  • AR antireflection
  • the illustrative embodiment is a diffusion-bonded composite crystal
  • a functional embodiment of the invention could be made of glass.
  • a functional embodiment could be fabricated of any transparent solids bonded together in any way (such as index-specific optical cements) that maintains the desired guiding properties and which will not overheat or damage at the optical power levels involved.
  • a further advantage is that the cladding leads to more effective cooling of the doped core than would be possible if a gain element of the core's size were directly cooled by impingement or conventional forced-convection cooling.
  • the ⁇ T between the surface being cooled and the coolant is directly proportional to the heat per area and inversely proportional to a heat transfer coefficient.
  • the total temperature drop between the core and the coolant is smaller for the clad device.
  • Another advantage of the present invention is that it makes end pumping of low absoiption cross-section materials, such as Yb:YAG possible. It allows use of a long piece of material, in either a core-pumped or a cladding-pumped geometry.
  • Parasitic oscillation is prevented by selection of the relative indices of the core and cladding to disallow parasitic oscillation for the particular core cross sectional shape selected. Previous end-pumping schemes have failed because of the parasitic oscillation issue. BRIEF DESCRIPTION OF THE DRAWINGS
  • Fig. 1 is a sectional side view of an optical amplifier constructed in accordance with the teachings of the present invention.
  • Fig. 2 is an end view of the optical amplifier of Fig 1.
  • Fig. 3 is a plot of the calculated temperature differential from the center of the rod to the flowing water for a circular cylindrical YAG rod clad with Sapphire, being cooled with forced convection of water.
  • Fig. 4 is a diagram showing two possible clad rod end configurations of an optical amplifier constructed in accordance with the teachings of the present invention, showing paths of rays at extremes of numerical aperture.
  • Fig. 1 is a sectional side view of an optical amplifier constructed in accordance with the teachings of the present invention.
  • Fig. 2 is an end view of the optical amplifier of Fig 1.
  • the amplifier 10 includes a first crystal 12, having a geometric and propagation axis 14 associated with it, and having a first index of refraction m.
  • a second crystal 16 is bonded to the first crystal 12 about the axis 14 and it has a second index of refraction n 2 .
  • the diffusion bonded interfaces between the first and second crystals 12 and 16 should be free of gaps, voids, and inclusions.
  • the first index m is slightly higher than the second index n 2 such that light through the first crystal is totally internally reflected.
  • the amplifier 10 has first and second ends 18 and 19.
  • the ends 18 and 19 have a substantially greater diameter than the cladding 16.
  • the ends 18 and 19 are made of Sapphire.
  • the proximal and distal ends 20 and 22 of the first crystal 12, extending through the first and second ends 18 and 19, respectively, are fabricated with clear undoped YAG.
  • the small diameter midsection portion 24 of the amplifier is commercial grade-polished. All surfaces, other than the ends, are rough ground.
  • the first crystal 12 is concentric within the second crystal 16, within 0.2 mm in the best implementations of the invention.
  • the Sapphire-clad rod has no doped YAG surface where breakage can start, since the YAG is completely enclosed in the much stronger Sapphire. As the power and the temperature go up, the YAG rod 12 is increasingly compressed. The Sapphire surface 16 is under tension, but the Sapphire cladding's thickness should be chosen to adequately resist the YAG rod's expansion while also maximizing conductive heat removal. Because (1) the surface tensile stress on a larger diameter cladding (note that little or no heat should be generated in the cladding) is smaller than the stress on an unclad rod at the same internal heating, (2) Sapphire is stronger than YAG, and (3) the cladding can be thick, the clad rod can operate at much higher power without breaking than can an unclad rod.
  • the governing high power laser crystal cooling issue is the large surface heat flux (heat per area), upwards of 100 Watts/cm in practice.
  • the temperature differential ( ⁇ T) across a crystal-to-liquid-coolant interface is proportional to this heat flux and inversely proportional to the heat transfer coefficient.
  • the transfer coefficient can be maximized with well-designed impingement cooling.
  • the inventive clad rod provides a further means to reduce this ⁇ T by reducing the heat flux at the surface of the crystal, simply because even though the total heat coming out of the crystal is the same, the area of the outside of the cladding is larger than that of the unclad rod.
  • the reduction in the water/material interface ⁇ T is traded against the conductive ⁇ T in the Sapphire cladding, which can be small because Sapphire has high thermal conductivity.
  • G is the total heat originating in the YAG part of the length, L, of composite rod being considered
  • R is the outer radius of the Sapphire cladding, assumed to be a circular cylinder
  • r is the radius of the YAG, also assumed to be a circular cylinder
  • h is the surface heat transfer coefficient
  • Ksap hire is the thermal conductivity of Sapphire (0.33 W/cmK)
  • KYAG is the thermal conductivity of Yb:YAG (O.lW/cmK).
  • Circular cylinders are assumed so closed-form mathematical expressions can be written; although round cores can not currently be diffusion bonded in practice, the essential results of the thermal calculation are similar for the realizable shapes, which are best modeled by numerical methods.
  • the first term comes from the heat transfer in the water boundary layer.
  • the second term describes conduction through the Sapphire (in which we assume no heat is generated); it has the logarithmic dependence typical of cylindrical geometry.
  • the third term describes the heat generation and thermal conduction in the Yb:YAG; this ⁇ T is independent of the diameter of the rod and depends only on the heat generated per length.
  • Fig. 3 is a plot of the calculated temperature differential from the center of the rod to the water for a circular cylindrical YAG rod clad with Sapphire.
  • the total ⁇ T is plotted as a function of the outside diameter of the Sapphire, assuming a fixed YAG diameter of 2mm and a modest fixed heat load of lO W/cm, with the heat transfer coefficient as a parameter. Note that it is advantageous to have cladding when the heat transfer coefficient is small. Cooling uniformity can also be superior for a clad rod.
  • the uniformity depends on the quality of the diffusion bonding and on the geometry, whereas for direct liquid cooling the uniformity depends on the details of the coolant flow; good uniformity with impingement cooling is obtained by using a large number of small jets. Thus, for a clad rod, a less refined impingement design may be used. Mechanical vibration is also less of an issue.
  • the Sapphire sleeve improves the cooling except when the heat transfer coefficient h is very high, and even in this case the ⁇ T penalty for having the cladding is insignificant.
  • the cladding can bring the, ⁇ T to within a factor of two of the ⁇ T obtainable with order-of-magnitude larger heat transfer coefficients.
  • High heat transfer coefficients require careful impingement design and large pressure drops and flow volumes.
  • the other benefits of cladding such as homogenization of the spatial nonuniformities inherent to impingement cooling, added strength and thermal fracture resistance, and the corrosion resistance of the Sapphire surface, more than make up for this.
  • the Sapphire surface properties can be optimized for maximum heat transfer, rather than for its optical properties. Because Sapphire is so much stronger than YAG, and because the surface strain can be reduced by making the crystal larger, it is not necessary to optimize the surface for fracture strength. In deciding on the relative dimensions of the cladding and the core, several issues should be considered:
  • Cooling issues drive the dimensions of the cladding via the tradeoffs summarized in Fig. 3. There is a range of core and cladding dimensions that optimize cooling. There is a size that is best for parasitic suppression.
  • the cladding needs to be polished if cladding pumping is used, and lasing theory, including knowledge of the available diode etendue, indicates that there is an optimal ratio for cladding area versus core area for a given doping.
  • the core Due to the nature of diffusion bonding technology, the core is necessarily rectangular, or, with a larger number of fabrication steps, polygonal.
  • a square core is employed as illustrated in Fig. 2, with dimensions determined mainly by the tradeoff between good extraction efficiency, which argues for a small core, and the desire to end pump directly into the core, which argues for large core. This tradeoff may be summarized as follows.
  • the saturation intensity for the Yb:YAG lasing transition utilized in the illustrative embodiment is 9.1 kW/cm 2 , or 91 W/mm 2.
  • the saturation intensity for the Yb:YAG pumping transition of the illustrative embodiment is 24 kW/cm , or 240 W/mm , and the diodes must be capable of delivering on this order of intensity to pump into the core.
  • the width of the core is 1 mm.
  • Fig. 4 is a diagram showing two possible clad rod end configurations, showing paths of rays at extremes of numerical aperture. One has tilted a tilted end face and the other end face is perpendicular to the guide axis. Note that the length of the doped Yb:YAG core shown is arbitrary and the exact geometry of the end caps is diagrammatic. Both of these end-cap embodiments differ from that of Figs. 1 and 2 in that the ends are entirely Sapphire, whereas in the Figs. 1 and 2 embodiment the core extended all the way to the end (which was tilted). The designs of Fig.
  • Fig. 4 are preferred for a guided amplifier inasmuch as it these designs have the end caps entirely made out of Sapphire, rather than having an undoped YAG core all the way to the ends.
  • the embodiments of Fig. 4 cannot be assembled without at least one Sapphire "c"-face, or close (-10° away) to "c"-face, diffusion bond. Unfortunately, diffusion bonds of this kind are currently difficult to manufacture.
  • Fig. 4 illustrates another issue relevant to guided amplifier design.
  • the geometry of a 10° tilted end faces is shown at the right. Rays are indicated at the extremes of the numerical aperture of the guided core.
  • a problem that arises when tilted ends are used with a guided rod can be understood from examination of this figure. It will be seen that a significant fraction of the rays pass through the end surfaces at very large angles of incidence, approaching 43 ° - It is challenging to produce an antireflection coating that functions well at both the pump and signal wavelength over the full range of angles from zero to 43 ° - Li the normal incidence situation, shown at the left of the figure, the coating needs specification only out to 22°, within the capability of standard coatings.
  • a minimal tilt of approximately -1-3 ° is applied to the rod ends. This tilt should be sufficient to direct stray reflections out of the beamline.
  • the small signal gain of the amplifier is 35, so that parasitic oscillation from the end faces should not occur so long as their reflection is less than about 3%.
  • the guided amplifier of the present invention is of course applicable to other laser ions, such as neodymium (Nd) or thulium (Tm), and other crystal hosts, such as YLF, YALO, and so on.
  • the invention is particularly useful for mechanically weak or thermally poor hosts.
  • the present teachings have enabled the construction of Yb: YAG amplifiers with CW gain greater than 10.

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Optics & Photonics (AREA)
  • Lasers (AREA)

Abstract

L'invention concerne un amplificateur optique à gain élevé et un procédé s'y rapportant. L'amplificateur comprend, en général, un premier cristal (12) présentant un axe (14) et un premier indice de réfraction; et un second cristal (16) fixé au premier cristal (12) autour de l'axe (14) et présentant un second indice de réfraction. Le premier indice est supérieur au second indice, si bien que la lumière traversant le premier cristal est complètement réfléchie intérieurement. Dans le mode de réalisation exemplaire, le premier cristal (12) est Yb: YAG avec un indice de 1.82 approximativement; le second cristal (16) est un saphir avec un indice de 1.78 approximativement; et l'axe (14) est l'axe de propagation. Dans le mode de réalisation préféré, on décrit un guide optique fabriqué à partir de matériaux cristallins soudés ensemble par diffusion. Si le coeur du guide optique est dopé aux ions laser, des amplificateurs à gain élevé peuvent être mis au point et exploités sur une grande échelle. Si le choix du cristal laser et des matériaux de gainage, de la forme et de la technique de soudage est effectué de manière judicieuse, l'amplificateur doté du guide optique sera moins exposé à l'oscillation parasite que les amplificateurs construits selon des préceptes classiques. Le coeur gainé pourra également supporter des charges thermiques plus importantes, sans rupture, qu'il n'est le cas avec un coeur non gainé.
EP02704243A 2002-01-24 2002-01-24 Amplificateur laser a gain eleve Withdrawn EP1362394A1 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US2002/002205 WO2003063306A1 (fr) 2002-01-24 2002-01-24 Amplificateur laser a gain eleve

Publications (1)

Publication Number Publication Date
EP1362394A1 true EP1362394A1 (fr) 2003-11-19

Family

ID=27608981

Family Applications (1)

Application Number Title Priority Date Filing Date
EP02704243A Withdrawn EP1362394A1 (fr) 2002-01-24 2002-01-24 Amplificateur laser a gain eleve

Country Status (2)

Country Link
EP (1) EP1362394A1 (fr)
WO (1) WO2003063306A1 (fr)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2861223A1 (fr) * 2003-10-21 2005-04-22 Commissariat Energie Atomique Dispositif de pompage optique par diodes laser et procede de pompage optique associe.
CN100346541C (zh) * 2005-03-31 2007-10-31 中国工程物理研究院激光聚变研究中心 一种大口径掺钛蓝宝石晶体的包边方法

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5936984A (en) * 1997-05-21 1999-08-10 Onxy Optics, Inc. Laser rods with undoped, flanged end-caps for end-pumped laser applications
US6115400A (en) * 1997-08-20 2000-09-05 Brown; David C. Total internal reflection thermally compensated rod laser
US5974061A (en) * 1997-12-19 1999-10-26 Raytheon Company Laser pump cavity apparatus with improved thermal lensing control, cooling, and fracture strength and method
US6160824A (en) * 1998-11-02 2000-12-12 Maxios Laser Corporation Laser-pumped compound waveguide lasers and amplifiers

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO03063306A1 *

Also Published As

Publication number Publication date
WO2003063306A1 (fr) 2003-07-31

Similar Documents

Publication Publication Date Title
US6785304B2 (en) Waveguide device with mode control and pump light confinement and method of using same
US7430230B2 (en) Tube solid-state laser
US20070297469A1 (en) Cryogenically Cooled Solid State Lasers
US6256142B1 (en) End pumped zig-zag slab laser gain medium
US6268956B1 (en) End pumped zig-zag slab laser gain medium
US6587488B1 (en) Control of parasitic laser oscillations in solid-state lasers by frustrating total internal reflections
US6646793B2 (en) High gain laser amplifier
EP3641081B1 (fr) Laser à plaque à haute puissance entièrement solide basé sur l'émission du bord de bande de phonons
US6763050B2 (en) Method for optical pumping of thin laser media at high average power
US7388895B2 (en) Corner-pumping method and gain module for high power slab laser
JPH1027930A (ja) モノリシックポンプ空洞および方法
JPH09508753A (ja) 強熱レンズ結晶を備えたダイオードポンプ型レーザ
JP3169614B2 (ja) 強い熱集束をもつ結晶を用いたダイオードポンピングレーザ
JP2000244042A (ja) 光導波路並びにその光導波路を用いたレーザ発振器およびレーザ増幅器
JP2001521290A (ja) 強い熱集束を有する利得媒体を用いるダイオード励起レーザ装置
Tsunekane et al. High-power operation of diode edge-pumped, glue-bonded, composite Yb: Y3Al5O12 microchip laser with ceramic, undoped YAG pump light-guide
US7382818B2 (en) Diffusion bonded pump cavity
US6567452B2 (en) System and method for pumping a slab laser
US20040076211A1 (en) Solid state laser amplifier
US6895152B2 (en) Guided-mode laser apparatus with improved cladding structure and a method of fabricating thereof
WO2003063306A1 (fr) Amplificateur laser a gain eleve
Mackenzie Power-scaling Nd: YAG's quasi-four-level transition
JP6888533B2 (ja) 結晶ファイバ光源
Dascalu et al. High-power lens-shape diode edge-pumped composite laser
Taira et al. High-power edge pumped Yb: YAG single crystal/YAG ceramics hybrid microchip laser

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20021025

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

17Q First examination report despatched

Effective date: 20041115

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20050330