WO2003025641A1 - Apparatus and method for thermally tuning an optical amplifier - Google Patents
Apparatus and method for thermally tuning an optical amplifier Download PDFInfo
- Publication number
- WO2003025641A1 WO2003025641A1 PCT/US2002/022105 US0222105W WO03025641A1 WO 2003025641 A1 WO2003025641 A1 WO 2003025641A1 US 0222105 W US0222105 W US 0222105W WO 03025641 A1 WO03025641 A1 WO 03025641A1
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- WO
- WIPO (PCT)
- Prior art keywords
- waveguide
- doped
- temperature
- amplifier
- light
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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
- H01S3/063—Waveguide lasers, i.e. whereby the dimensions of the waveguide are of the order of the light wavelength
- H01S3/067—Fibre lasers
- H01S3/06754—Fibre amplifiers
-
- 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
- H01S3/10007—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating in optical amplifiers
- H01S3/10013—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating in optical amplifiers by controlling the temperature of the active medium
-
- 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
- H01S3/1301—Stabilisation of laser output parameters, e.g. frequency or amplitude in optical amplifiers
- H01S3/13013—Stabilisation of laser output parameters, e.g. frequency or amplitude in optical amplifiers by controlling the optical pumping
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/02—Optical fibres with cladding with or without a coating
- G02B6/036—Optical fibres with cladding with or without a coating core or cladding comprising multiple layers
- G02B6/03605—Highest refractive index not on central axis
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/02—Optical fibres with cladding with or without a coating
- G02B6/036—Optical fibres with cladding with or without a coating core or cladding comprising multiple layers
- G02B6/03694—Multiple layers differing in properties other than the refractive index, e.g. attenuation, diffusion, stress properties
-
- 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
- H01S2301/00—Functional characteristics
- H01S2301/04—Gain spectral shaping, flattening
-
- 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
- H01S3/063—Waveguide lasers, i.e. whereby the dimensions of the waveguide are of the order of the light wavelength
- H01S3/067—Fibre lasers
- H01S3/06704—Housings; Packages
-
- 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
- H01S3/1616—Solid materials characterised by an active (lasing) ion rare earth thulium
Definitions
- the present invention relates to optical systems and, in particular, to apparatus and methods for tuning optical amplifiers and for cooling optical waveguides.
- Optical fibers are the transmission medium of choice for handling the large volume of voice, video, and data signals that are communicated over both long distances and local networks.
- Much of the interest in this area has been spurred by the significant increase in communications traffic, which is due, at least in part, to the Internet. Consequently, much interest is directed to increasing the data handling capacities of the optical fibers that comprise the communications networks.
- One way of increasing the capacity of optical fibers is to increase the number of channels or signals that are transmitted through each optical fiber. However, there are several technical difficulties with increasing the number of channels.
- One limitation is that only certain wavelengths of optical signals can be efficiently transmitted through an optical fiber.
- the most efficient wavelengths i.e. those with low loss per unit length
- the S-band, C-band and L-band which comprise wavelengths from approximately 1460 nm through 1630 nm.
- Signals having wavelengths outside of this range suffer increased signal loss and are therefore cannot be transmitted efficiently along optical fibers.
- Another limitation is related to amplifying the signals in the S, C, and L -bands when the signals are transmitted for long distances. Although modern optical fibers have very low loss per unit length, they nonetheless require periodic amplification of the transmitted signal to ensure accurate reception at a receiver. Initially, electronic amplifiers were used to amplify these optical signals. Electronic amplifiers converted the optical or light signals into electrical signals, amplified the electrical signals, and then retransmitted the signals as light signals. This was an expensive and inefficient way to amply optical signals.
- Optical amplifiers comprise a length of optical waveguide or fiber that is doped with a suitable fluorescent material such as erbium ions or thulium ions.
- a pump light source is injected into the doped fiber to excite the fluorescent ions.
- the excited ions release their energy at the same wavelength as the signal and thereby produce a highly amplified signal.
- erbium doped fiber amplifiers are primarily useful only in the C-band and, to a lesser extent, in the L-band.
- EDFA erbium doped fiber amplifier
- the prior art has attempted to develop exotic doping materials to create an improved optical amplifier.
- the prior art has also experimented with various complex light pumping schemes to improve the performance of optical amplifiers.
- Yet another challenge confronting the industry are the increasingly tough specifications for amplifiers. Gain shaping, gain flattening, and gain tilt compensation are becoming more and more important as ripple and bandwidth specifications get tougher and wider.
- the continuing challenge is to find an apparatus and method to increase the bandwidth of optical amplifiers and shape and flatten the gain of amplifiers so that the transmission capacity of optical fibers can be increased.
- the invention discloses an apparatus and method for thermally tuning an optical amplifier which comprises: an optical wave guide doped with a fluorescent material, a thermal device for either heating or cooling the optical wave guide, and a pump light source for exciting the fluorescent material.
- an optical wave guide doped with a fluorescent material for either heating or cooling the optical wave guide
- a thermal device for either heating or cooling the optical wave guide
- a pump light source for exciting the fluorescent material.
- the invention uses this discovery to shape, shift, and/or flatten the gain curves of doped optical amplifiers to achieve the desired results. For example, thulium doped optical fiber is cooled to shift the gain curve into longer, more useful wavelengths.
- erbium doped optical fiber is cooled to shift the gain curve to longer wavelengths above the L-band.
- an erbium doped optical fiber is heated to flatten the gain curve in the C-band.
- the invention may also be used to shape the gain curves of other fluorescent materials used in optical amplifiers.
- the first optical cooling device comprises an optical fiber (cooling fiber) doped with an appropriate fluorescent refrigerant material and coupled with a pump light source.
- the cooling fiber is co-wound with an amplifying fiber and the cooling fiber is cooled as the pump light is activated.
- the amplifying fiber is cooled by the cooling fiber due to their close proximity.
- a second embodiment comprises doping the cladding of the optical amplifier fiber with a fluorescent refrigerant such as ytterbium.
- a pump light source is coupled with the cladding to cause the cladding to cool and thereby cause the core of the fiber amplifier to cool.
- some fluorescent refrigerants, such as ytterbium produce pump light as a by-product. This pump light may then be used to pump the fluorescent material in the core.
- a third embodiment comprises an optical fiber amplifier having two cores.
- a first core is doped with a fluorescent material suitable for amplifying an optical signal.
- the second core is doped with a fluorescent refrigerant material. When pump the is applied to the second core, the core cools and also causes the nearby first core to cool.
- the apparatus is useful in not only in telecommunication systems, but also in laser printers, laser marking, medical imaging, microsurgery, scientific research and development, and the like. It follows that the method of the invention comprises either heating or cooling an optical waveguide doped with fluorescent material to achieve desired shaping, shifting, and flattening of the gain curves.
- Fig. 1 illustrates a fluorescence curve for thulium which is representative of the gain curve of thulium
- Fig. 2 a and b illustrates various Stark energy level transitions when thulium at different temperatures
- Fig. 3 illustrates the population distribution among the nine Stark sublevels at various temperatures
- Figs. 4 illustrates the quantum efficiency of thulium ions over temperature
- Figs. 5 illustrates the fluorescence curve for erbium which is representative of the gain curve for erbium
- Fig. 6 is a diagram of the gain of an exemplary amplifier, at 0°C and 70°C and pump laser diode operating at current of 105mA and 110mA;
- Fig. 7 is a diagram of amplifier's Gain Tilt at 0°C and 70°C of an exemplary amplifier with the pump laser diode operating at a current of 105mA and 110mA;
- Fig. 8 is a schematic diagram of the preferred embodiment of the invention;
- Fig. 9 is a schematic diagram of the invention heating an optical amplifier;
- Fig. 10 is a schematic diagram of the invention embodied in a fiber optic laser;
- Fig. 11 is a schematic diagram of the invention comprising a co-wound optical cooling waveguide;
- Fig. 12 A is a schematic diagram of the invention comprising fluorescent refrigerant doped in the amplifying fiber;
- Fig. 12 B is a cross section of an amplifying fiber doped with fluorescent refrigerant in the cladding
- Fig. 12 C is a cross section of an amplifying fiber having a second core doped with fluorescent refrigerant
- the invention entails controlling the temperature of the optically active gain medium (e.g. the fluorescent material) in an optical amplifier to increase the performance and utility of the device.
- the optically active gain medium e.g. the fluorescent material
- FIG. 1 illustrates the fluorescence spectrum of the thulium Tm ⁇ + as a function of temperature in 50 degree Kelvin increments. Since the Tm3 + emission is a four level transition, the fluorescence curve is indicative of the gain curve of a thulium-doped amplifier. At normal room temperature, much of the gain curve is in the undesirable spectrum below 1500 nm. However, as the temperature is decreased, the fluorescence intensity on the red side (i.e. longer wavelengths) of the spectrum, in the desirable 1500 nm region, increases at the expense of the useless fluorescence at 1400 mn. The gain shape also changes considerably with temperature and this is used to decrease gain ripple.
- Figure 2A illustrates the 81 possible transitions at room temperature.
- Figure 2B illustrates the four transitions possible at cold 10 degrees Kelvin.
- the seven small dashes are representative of the Stark levels, but each of these levels are essentially empty at low temperatures.
- FIG 3 there is illustrated the relative population distribution of the thulium 3H4 Stark levels at various temperatures.
- low temperatures e.g., 10 degrees Kelvin
- the population is entirely confined to the two lowest lying Stark components and as the temperature increases there is enough thermal energy to distribute the population to the higher lying Stark components.
- the population among the initial level shifts to the lowest lying states resulting in a red shifting of the fluorescence since the ions are starting in a lower energy state.
- the absorption bands will blue shift to higher energies as the temperature is decreased since the ions are starting from lower Stark levels making the absorption energy gap effectively larger.
- FIG. 5 shows the fluorescence spectrum of an erbium ion (Er3 + ) doped fiber as a function of temperature. As the fiber is cooled from high temperature, the fluorescence red shifts toward longer wavelengths. This is advantageous for an L-band amplifier which normally would operate on the weaker erbium fluorescence in the 1580 to 1610 nm region. Cooling the erbium fiber, for example to -200 degrees C, can therefore produce approximately a 10-20% gain advantage over higher temperature fiber.
- the gain advantage in the region of 1600 to 1630 and especially 1610 nm to 1630 nm is particularly useful in extending the bandwidth of the erbium doped fiber amplifier (EDFA).
- EDFA erbium doped fiber amplifier
- FIG. 8 there is illustrated a schematic diagram of a preferred embodiment of the invention as a thulium doped fiber amplifier (TmDFA) 60.
- a light signal 61a is coupled into fiber 62 from light signal source 61.
- Signal source 61 is typically a telecommunications network or some component thereof.
- Light signal 61a preferably has wavelengths in the range of 1460 nm to about 1540 nm and more preferably in the range of the S-band or 1485 nm to 1525 nm.
- Light signal 61a is transmitted through fiber 62 to amplifying fiber 63.
- the symbol indicating amplifying fiber 63 is a loop since the doped optical fibers are typically coiled due to space limitations.
- Amplifying fiber 63 is preferably doped with either erbium or thulium, however the invention may be practiced with most any fluorescent material including the family of rare earth elements such as: cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), ytterbium (Yb).
- rare earth elements such as: cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (
- the amplifying fiber 63 may be a planar waveguide or, in general, any type of optical waveguide.
- Pump light source 64 provides pump light 64a for exciting the erbium ions in amplifying fiber 63.
- Light source 64 is preferably a semiconductor laser operating at about 980 nm or 1480 nm wavelengths. However, various other sources of pump light may also be used.
- Pump light 64a is coupled to fiber 62 via optical coupler 62a.
- Cooling of the amplifying fiber 63 is accomplished by cooling device 65, which is preferably a thermal electric (TE) cooler.
- Amplifying fiber 63 is wound or coiled around the TE cooler 65.
- the amplifying fiber 63 is wound around a thermally conducting material, such as aluminum, which is thermally coupled to the TE cooler 65.
- TE coolers are known in the art. Recent advances in TE coolers useful to the instant invention. Cooling may be accomplished by virtually any cooling means, including air cooling and liquid cooling. Another cooling option is optical or fluorescent cooling which is described in detail below.
- the cooling of amplifier fiber 63 may be regulated via a temperature sensor 66 in communication with a controller 67, which regulates cooling device 65.
- Temperature sensor is preferably a thermo-couple device that generates a temperature signal 66a indicative of the temperature of amplifying fiber 63.
- Controller 67 is a conventional digital control unit programmed to implement a suitable feedback control algorithm.
- the desired temperature of the amplifying fiber 63 will vary depending on the requirements and specifications of a particular application. Generally the fiber 63 should be cooled below 270 degrees Kelvin. Preferably the fiber 63 is cooled to about 200 degrees Kelvin. More preferably the fiber 63 is cooled to about 150 degrees Kelvin and most preferably the fiber 63 is cooled to about 100 degrees Kelvin. It is also preferred to cool the fiber 63 to about 50 degrees Kelvin.
- Light signal 61a is transmitted through amplifying fiber 63 where the signal is amplified manyfold and the amplified signal is output on output fiber 68.
- a heating device 71 heats the amplifying fiber 63.
- the gain curve of an erbium-doped optical fiber will flatten as the temperature increases.
- the signal source 61, pump light source 64, temperature sensor 66, and controller 67 are identical to the components in Figure 8.
- Amplifying fiber 63 is preferably heated above 200 degrees C, and more preferably heated to above 400 degrees C, and still more preferably heated above 600 degrees C, and most preferably heated to about 800 degrees C.
- Heating device 71 is a resistive heating element but may also be any other type of heating device including air heating, radiant heating, inductive heating, or the like.
- a particularly useful application for the invention is in fiber lasers, an exemplary schematic of which is illustrated in Figure 10.
- Pump light 64 injects pump light into amplifying fiber 63.
- a light signal 61a may also be injected by light signal source 61.
- the light signal is amplified by amplifying fiber 63 and output to grating 81 which allows a portion of the light to pass and reflecting a portion of the light back into amplifier fiber 63 as is commonly known.
- a problem with fiber lasers is that it is difficult to obtain laser light of various wavelengths.
- the invention solves this problem my enabling the amplifying fiber 63 to be tuned to a desired wavelength by controlling the temperature. Using the invention, previously difficult to generate laser wavelengths are easily generated.
- an optical cooling device comprises a light waveguide doped with an appropriate fluorescent refrigerant and pumped with an suitable light wavelength. The absorption of thermal energy presumably produces the cooling effect.
- a cooling optical fiber 91 (dashed line) is doped with such a fluorescent refrigerant and co-wound with the amplifying fiber 63.
- the cooling pump 92 launches pump light into cooling optical fiber 91.
- fiber 91 cools the co-wound amplifying fiber is also cooled.
- a temperature sensor and controller may be added to control the cooling process as was done in Figure 8.
- the fluorescent refrigerant is doped into the same optical waveguide as the amplifying fiber 63. This is accomplished in at least two ways. First, as illustrated in Figure 12B, the fluorescent refrigerant 101 is doped into the cladding or outer layer 103 of amplifying fiber 63. Light signals 61a are transmitted via core 102 while light is pumped through the cladding 103 causing the cladding 103 to cool. As the cladding 103 is cooled, the core 102 is also cooled.
- the amplifying fiber 63 comprises a second core 105 doped with fluorescent refrigerant. Pump light is injected through the second core 105 causing it to cool and consequently cooling the central core 102.
- Figure 12 illustrates a schematic diagram of these two embodiments.
- the amplifying fiber 63 and pump light source 64 are identical to those in Figure 8.
- Cooling pump 92 is added to inject pump light into either the cladding or second core of amplifying fiber 63 via optical coupling 62b.
- a light waveguide is provided that is doped with a fluorescent material suitable for being excited by pump light and amplifying a light signal.
- a pump light source is provided and optically coupled to the light waveguide providing a suitable pump light to excite the fluorescent material.
- a thermal device such as a heating device, a cooling device, or optical cooler is thermally coupled to the light waveguide.
- a temperature sensor senses the temperature of the waveguide and communicates a temperature signal to a controller, which in turn controls the thermal device to achieve a desired waveguide temperature.
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- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
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- Optics & Photonics (AREA)
- Lasers (AREA)
Abstract
Description
Claims
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP02744864A EP1436651A1 (en) | 2001-09-20 | 2002-07-11 | Apparatus and method for thermally tuning an optical amplifier |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/961,115 | 2001-09-20 | ||
US09/961,115 US6694080B2 (en) | 2001-09-20 | 2001-09-20 | Apparatus and method for thermally tuning an optical amplifier |
Publications (1)
Publication Number | Publication Date |
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WO2003025641A1 true WO2003025641A1 (en) | 2003-03-27 |
Family
ID=25504079
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US2002/022105 WO2003025641A1 (en) | 2001-09-20 | 2002-07-11 | Apparatus and method for thermally tuning an optical amplifier |
Country Status (3)
Country | Link |
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US (1) | US6694080B2 (en) |
EP (1) | EP1436651A1 (en) |
WO (1) | WO2003025641A1 (en) |
Families Citing this family (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3965975B2 (en) * | 2001-11-13 | 2007-08-29 | 住友電気工業株式会社 | Optical amplifier and optical communication system |
US7525725B2 (en) * | 2002-03-05 | 2009-04-28 | Sumitomo Electric Industries, Ltd. | Optical amplification module, optical amplifier, optical communication system, and white light source |
US7208007B2 (en) * | 2003-08-07 | 2007-04-24 | Cutera, Inc. | System and method utilizing guided fluorescence for high intensity applications |
US7130110B2 (en) * | 2004-10-22 | 2006-10-31 | Sanmina-Sci Corporation | Temperature control in an optical amplification system |
FR2903818B1 (en) * | 2006-07-11 | 2008-09-05 | Thales Sa | METHOD AND DEVICE FOR SPECTRAL CONTROL IN FREQUENCY DERIVED LASER CHAINS |
WO2008072033A1 (en) * | 2006-12-11 | 2008-06-19 | Consiglio Nazionale Delle Ricerche- Infm Istituto Nazionale Per La Fisica Della Materia | A surgical apparatus and a method for treating biological hard tissues, particularly for dental surgery, based on a fibre laser |
US8261557B2 (en) * | 2008-12-05 | 2012-09-11 | Raytheon Company | Heat transfer devices based on thermodynamic cycling of a photonic crystal with coupled resonant defect cavities |
US8111724B2 (en) | 2009-07-07 | 2012-02-07 | International Business Machines Corporation | Temperature control device for optoelectronic devices |
US9343864B2 (en) * | 2011-02-10 | 2016-05-17 | Soreq Nuclear Research Center | High power planar lasing waveguide |
EP2880721B1 (en) * | 2012-07-30 | 2020-12-23 | Technion Research & Development Foundation Ltd. | Energy conversion system |
US10989450B1 (en) * | 2016-07-13 | 2021-04-27 | Triad National Security, Llc | Solid-state optical refrigerator for cryogenic cooling of payloads |
US9787048B1 (en) | 2016-10-17 | 2017-10-10 | Waymo Llc | Fiber encapsulation mechanism for energy dissipation in a fiber amplifying system |
Citations (6)
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JPH02300727A (en) * | 1989-05-15 | 1990-12-12 | Nippon Telegr & Teleph Corp <Ntt> | Optical fiber amplifier |
US5406410A (en) * | 1990-09-03 | 1995-04-11 | British Telecommunications Plc | Optical fibre amplifier and laser |
US5447032A (en) * | 1994-04-19 | 1995-09-05 | The Regents Of The University Of California | Fluorescent refrigeration |
US6147795A (en) * | 1999-06-21 | 2000-11-14 | Lucent Technologies Inc. | Retrofit heater for erbium fiber in an erbium-doped fiber amplifier (EDFA) |
US6320693B1 (en) * | 1998-06-30 | 2001-11-20 | Corning Incorporated | Thermal tuning of optical amplifiers and use of same in wavelength division multiplexed systems |
US6452717B1 (en) * | 1999-02-05 | 2002-09-17 | Sumitomo Electric Industries, Ltd. | Fiber optic amplifier |
Family Cites Families (9)
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IT1215681B (en) * | 1988-01-12 | 1990-02-22 | Pirelli General Plc | AMPLIFICATION OF OPTICAL SIGNALS. |
US4947648A (en) | 1988-06-17 | 1990-08-14 | Microluminetics, Inc. | Thermoelectric refrigeration apparatus |
US5345332A (en) * | 1993-05-03 | 1994-09-06 | Bell Communications Research, Inc. | Fiber amplifier cascade for multiwavelength lightwave communications system |
US6212310B1 (en) * | 1996-10-22 | 2001-04-03 | Sdl, Inc. | High power fiber gain media system achieved through power scaling via multiplexing |
WO1999052341A2 (en) | 1998-04-10 | 1999-10-21 | The Regents Of The University Of California | Optical refrigerator using reflectivity tuned dielectric mirror |
JP3903650B2 (en) * | 1999-06-18 | 2007-04-11 | 住友電気工業株式会社 | Optical amplifier and optical amplifier control method |
US6246511B1 (en) | 1999-08-12 | 2001-06-12 | Agere Systems Optoelectronics Guardian Corp. | Apparatus and method to compensate for optical fiber amplifier gain variation |
US6535329B1 (en) * | 1999-12-20 | 2003-03-18 | Jds Uniphase Inc. | Temperature tuning an optical amplifier |
JP3768110B2 (en) * | 2001-02-22 | 2006-04-19 | 富士通株式会社 | Optical amplifier |
-
2001
- 2001-09-20 US US09/961,115 patent/US6694080B2/en not_active Expired - Fee Related
-
2002
- 2002-07-11 EP EP02744864A patent/EP1436651A1/en not_active Withdrawn
- 2002-07-11 WO PCT/US2002/022105 patent/WO2003025641A1/en not_active Application Discontinuation
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH02300727A (en) * | 1989-05-15 | 1990-12-12 | Nippon Telegr & Teleph Corp <Ntt> | Optical fiber amplifier |
US5406410A (en) * | 1990-09-03 | 1995-04-11 | British Telecommunications Plc | Optical fibre amplifier and laser |
US5447032A (en) * | 1994-04-19 | 1995-09-05 | The Regents Of The University Of California | Fluorescent refrigeration |
US6320693B1 (en) * | 1998-06-30 | 2001-11-20 | Corning Incorporated | Thermal tuning of optical amplifiers and use of same in wavelength division multiplexed systems |
US6452717B1 (en) * | 1999-02-05 | 2002-09-17 | Sumitomo Electric Industries, Ltd. | Fiber optic amplifier |
US6147795A (en) * | 1999-06-21 | 2000-11-14 | Lucent Technologies Inc. | Retrofit heater for erbium fiber in an erbium-doped fiber amplifier (EDFA) |
Also Published As
Publication number | Publication date |
---|---|
EP1436651A1 (en) | 2004-07-14 |
US6694080B2 (en) | 2004-02-17 |
US20030053776A1 (en) | 2003-03-20 |
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