EP1563618A1 - Amplificateur optique multiports a reseau de pompe vcsel et commande de gain - Google Patents

Amplificateur optique multiports a reseau de pompe vcsel et commande de gain

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Publication number
EP1563618A1
EP1563618A1 EP03769046A EP03769046A EP1563618A1 EP 1563618 A1 EP1563618 A1 EP 1563618A1 EP 03769046 A EP03769046 A EP 03769046A EP 03769046 A EP03769046 A EP 03769046A EP 1563618 A1 EP1563618 A1 EP 1563618A1
Authority
EP
European Patent Office
Prior art keywords
optical
array
optical amplifier
pump
input
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Withdrawn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
EP03769046A
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German (de)
English (en)
Inventor
Kamran Edith Cowan University ESHRAGHIAN
Kamal Edith Cowan University ALAMEH
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Edith Cowan University
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Edith Cowan University
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Publication date
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Publication of EP1563618A1 publication Critical patent/EP1563618A1/fr
Withdrawn legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/29—Repeaters
    • H04B10/291—Repeaters in which processing or amplification is carried out without conversion of the main signal from optical form
    • H04B10/293—Signal power control
    • H04B10/294—Signal power control in a multiwavelength system, e.g. gain equalisation
    • H04B10/2942—Signal power control in a multiwavelength system, e.g. gain equalisation using automatic gain control [AGC]
    • 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
    • H01S5/00—Semiconductor lasers
    • H01S5/40—Arrangement of two or more semiconductor lasers, not provided for in groups H01S5/02 - H01S5/30
    • H01S5/42—Arrays of surface emitting lasers
    • H01S5/423—Arrays of surface emitting lasers having a vertical cavity
    • 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
    • H01S3/09—Processes or apparatus for excitation, e.g. pumping
    • H01S3/091—Processes or apparatus for excitation, e.g. pumping using optical pumping
    • H01S3/094—Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light
    • H01S3/094003—Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light the pumped medium being a fibre
    • H01S3/094019—Side pumped fibre, whereby pump light is coupled laterally into the fibre via an optical component like a prism, or a grating, or via V-groove coupling
    • 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
    • H01S3/09—Processes or apparatus for excitation, e.g. pumping
    • H01S3/091—Processes or apparatus for excitation, e.g. pumping using optical pumping
    • H01S3/094—Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light
    • H01S3/0941—Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light of a laser diode
    • H01S3/09415—Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light of a laser diode the pumping beam being parallel to the lasing mode of the pumped medium, e.g. end-pumping
    • 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
    • H01S3/1608—Solid materials characterised by an active (lasing) ion rare earth erbium
    • 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
    • H01S5/00—Semiconductor lasers
    • H01S5/02—Structural details or components not essential to laser action
    • H01S5/022—Mountings; Housings
    • H01S5/023—Mount members, e.g. sub-mount members
    • H01S5/02325—Mechanically integrated components on mount members or optical micro-benches
    • 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
    • H01S5/00—Semiconductor lasers
    • H01S5/02—Structural details or components not essential to laser action
    • H01S5/022—Mountings; Housings
    • H01S5/0233—Mounting configuration of laser chips
    • H01S5/0234—Up-side down mountings, e.g. Flip-chip, epi-side down mountings or junction down mountings
    • 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
    • H01S5/00—Semiconductor lasers
    • H01S5/06—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
    • H01S5/068—Stabilisation of laser output parameters
    • H01S5/0683—Stabilisation of laser output parameters by monitoring the optical output parameters

Definitions

  • the present invention relates to an optical amplifier, and, in particular a multi-port optical amplifier using Vertical Cavity Surface Emitting Laser (VCSEL) arrays and other components to provide dynamic pumping.
  • VCSEL Vertical Cavity Surface Emitting Laser
  • the invention has particular, although not exclusive, utility in optical telecommunications networks, photonic systems, photonic signal processors, and dense optical computer networks.
  • optical signals are attenuated by optical fibers and other optical components encountered by those optical signal.
  • Optical amplifiers are key devices within wide-area networks, local-area networks, cable TV distribution, computer interconnections, and anticipated new fibre-to-the-home applications, because their signal amplification is independent of the transmission bit rate and data format.
  • SOA's Semiconductor optical amplifiers
  • SOA's have the advantage of small size. However, they have several disadvantages, including limited gain and bandwidth, low saturation output power, high noise figure, high nonlinearity, and polarization dependent performance.
  • rare-earth-doped fibre amplifiers such as erbium doped fibre amplifier (EDFA)
  • EDFA erbium doped fibre amplifier
  • Their features include very low polarization sensitivity, high output power (as high as +37 dBm) and wide-bandwidth (up to 80 nm).
  • a rare-earth doped fibre amplifier operates by the same fundamentals as a laser, which is light amplification by stimulated emission of radiation.
  • the fibre amplifier is driven by another optical source (pump) to excite the active dopant (a rare-earth element) in one of its absorption bands.
  • the electrons in the rare-earth ions are pumped to an exited metastable state.
  • the success of rare-earth-doped fibre amplifiers is mainly due to the long emission lifetime of the metastable state, which permits large population inversions - as almost all ions are in a metastable excited state instead of in the ground state - needed to achieve high gain.
  • Rare- earth doped fibre amplifiers can be used for both the 1.3 ⁇ m and 1.55 ⁇ m optical telecommunication windows.
  • fluoride fibre doped with the rare earth element praseodymium
  • a silica-based fibre doped with the rare earth element erbium
  • existing silica-based EDFA's require long lengths of few metres for efficient gain performance.
  • High concentration erbium-doped phosphate glasses have recently emerged, which can miniaturize the optical amplifiers to such an extent that planar waveguide technology is possible. With the new glass composition, a waveguide of a few centimeters can achieve signal amplification of the same order of magnitude as current amplifiers with a length of about 10 metres.
  • Future dynamic optical networks will bomprise many nodes linked by a number of different fibre optic links for the transport of optical signals there between.
  • a dynamic optical network where each signal might be routed through a different group of optical components, a different amount of attenuation is experienced by each signal component.
  • Existing EDFA's do not satisfy the market's requirements of low cost, high-performance, efficient power management, and standards.
  • Discrete fibre amplifiers can operate at high bit rates, but they are large and expensive, hence their effectiveness is limited.
  • erbium- doped fibre amplifiers currently enable tens of millions of simultaneous telephone conversations across continents and under oceans on a single fibre-optic cable. But their high cost makes them economical only for long-haul systems, and their large size means that they cannot be integrated easily with other devices. A dramatic cost reduction in multi-port, high performance optical amplifiers will make a large impact on the design approach and implementation of future metropolitan and access optical networks.
  • an amplifier of input optical signals comprising:
  • input means for receiving input optical signals
  • beam generating means for generating pump beams
  • waveguide means for receiving the optical signals from the input means, and pump beams from the beam generating means, the waveguide means being arranged to absorb the received pump beams and operable to amplify the received optical signal using stimulated emission of radiation, the pump beams being used to drive the waveguide means to provide the stimulated emission;
  • the beam generating means is a vertical cavity surface emitting laser.
  • the amplifier further comprises routing means for receiving the input optical signals from the input means, and pump beams from the beam generating means, and for routing the received input optical signals and the pump beams to the waveguide means.
  • the routing means comprises a glass or sapphire substrate.
  • the routing means includes collimating and focusing means.
  • the collimating and focusing means comprise a microlens array, or, alternatively, diffractive optical elements.
  • the amplifier further comprises monitoring means for monitoring the power of the optical signals and the pump beams.
  • the monitoring means is a two-dimensional photodetector array.
  • the vertical cavity surface emitting laser is an integrated circuit, integrated with the photodetector array.
  • the input means has a multi-port configuration, particularly an array of optical fibres.
  • the waveguide means has a multi-port configuration comprising an array of optical fibres.
  • the fibres in the fibre array are either core-pumped or cladding- pumped.
  • the array comprises erbium-doped alumino-silicate fibres, or praseodymium-doped fluoride fibres.
  • the vertical cavity surface emitting laser operates in transverse single- mode.
  • the vertical cavity surface emitting laser operates in multi- mode.
  • the vertical cavity surface emitting laser is arranged with an external cavity resonator.
  • the amplifier further includes a first detecting means for detecting pump beam signals, and a processor to which pump beam monitoring signals are supplied, from the first detecting means, in response to the detected pump signals, the processor being operable to generate control signals for controlling the pump beam generating means, in response to the pump beam monitoring signals.
  • the first detecting means is a photodetector array integrated on a semiconductor chip.
  • the amplifier further includes a second detecting means for detecting the input signal beams, with input monitoring signals being supplied from the second detecting means to the processor in response to detected input signals, the processor being operable to generate control signals for controlling the beam generating means, in response to received input monitoring signals, and pump beam monitoring signals.
  • the second detecting means is a photodetector array.
  • the optical amplifier comprises:
  • an optical substrate having top and bottom faces and two side faces extending between the top and bottom faces so that the substrate has a square-shaped cross-section
  • VCSEL vertical cavity surface emitting laser
  • a bottom photodetector arranged proximate to the bottom face in alignment with the VCSEL array and the top photodetector array;
  • a routing element arranged in the substrate at 45° to the side faces having a beam splitting lower surface and a reflective upper surface, the lower surface transmitting a major portion of the input beams to the output doped fibre array and reflecting a minor portion of the input beams to the bottom photodetector array, the upper surface reflecting the pump beams to the output doped fibre array; and a processor for adjusting the power level of the pump beams in response to the power levels detected by the top and bottom photodetector arrays so that the gain of the optical amplifier can be selectively controlled.
  • This preferred embodiment eliminates free space beam propagation and allows the optical amplifier to be more compact.
  • the optical amplifier further includes an input microlens array etched in the optical substrate for collimating the input beams.
  • the optical amplifier further includes an output microlens array etched in the optical substrate for coupling the input beams and pump beams to the output doped fibre array.
  • the bottom photodetector array is flip-chip bonded to the optical substrate.
  • the VCSEL array is flip-chip bonded with an Ultra-Thin Semiconductor (UTS) chip that integrates the top photodetector array.
  • UTS Ultra-Thin Semiconductor
  • the output doped fibre array is an erbium doped fibre array.
  • the optical substrate comprises a glass or sapphire substrate.
  • a method for controlling the optical gains of an optical amplifier comprising the steps of:
  • Preferred embodiments of the invention have a reduced complexity and draw less power than most modem systems.
  • Figures 1A and 1B schematically illustrates the concept of rare-earth-doped fibre amplification
  • Figure 2 schematically illustrates a multi-port optical amplifier
  • Figure 3 schematically illustrates pumping an EDFA using a VCSEL source in accordance with the present invention
  • Figure 4 illustrates a two-dimensional (2D) optical amplifier architecture for an amplifier of the present invention
  • Figure 5 illustrates a schematic of a second embodiment of a 2D optical amplifier architecture in which a single 45° edge is used to route the signal and pump beams.
  • Figures 1A and 1B illustrate the principle of optical amplification in an erbium- doped optical fibre amplifier (EDFA) 1.
  • Figure 1A is a schematic representation of an EDFA
  • Figure 1B is an energy level diagram for the EDFA of Figure 1A.
  • the basic energy diagram of an EDFA is very similar to a 3-level laser system.
  • Supplying photons in a pump wavelength, ⁇ p (usually 980nm), excites the erbium electrons (i.e. increases their energy) to the excitation level. Then the excited electrons undergo a non-emission transition - that is a slight loss of energy - to a metastable level that has a long emission lifetime of approximately 10 ms.
  • Light photons in a signal wavelength, ⁇ s (usually about 1550nm), are amplified by stimulated emissions, and as in a laser, the emitted photons then stimulate other emissions, leading to an exponential growth of signal photons.
  • the long metastable emission lifetime allows high quantum efficiency and low noise figure to be attained. If the metastable emission lifetime were short, then electrons are relaxed too quickly, meaning more photons are spontaneously emitted giving rise to spontaneous noise, and more input pump is needed to keep the electrons in the metastable state.
  • the EDFA 1 requires a 880nm pump laser 2, a coupler 3, which combines a laser beam from the pump laser 2 with an input signal laser beam 4 into a single fibre 5, and the EDFA 1 , which is the amplification medium.
  • an optical filter (not shown) is used, after the EFDA 1 , to filter out the amplified spontaneous noise.
  • Erbium ions have quantum levels that allow them to be stimulated to emit in the 1550nm band, which is the wavelength of minimum power loss in most silica-based fibres. That gives them the ability to amplify signals in a wavelength where high-quality amplifiers are most needed.
  • EDFA's can be excited by a signal at either 800nm or 980nm, both of which silica-based fiber can carry without great losses, but aren't in the middle of the signal wavelengths. Those wavelengths are also far enough away from the signal wavelength of 1550 nm thus allowing the pump beam and the signal beam 4 to be easily separated. Erbium can also be excited by photons at 1480nm, but this is typically undesirable because both the energy pumping process and the stimulated emission by the signal take place in the same energy band, which causes interactions that lower the efficiency of the EDFA and increase the amplifier noise.
  • erbium for use in an EDFA is fairly soluble in silica, making it easy to dope into mixtures for making silica-based fibres, and by using a co-dopant, such as AI 2 O 3 , GeO 2 -Al 2 O 3 , or P Os, the erbium compound's solubility in the silica mixture can be greatly increased, and some of the EDFA's properties can be improved.
  • a co-dopant such as AI 2 O 3 , GeO 2 -Al 2 O 3 , or P Os
  • GeO -AI 2 O 3 can be used to almost double the time it takes for excited erbium to relax, which therefore almost doubles the quantum efficiency of the EDFA.
  • EDFA's gain varies with a signal's wavelength, which creates problems in many wavelength division multiplexing (WDM) applications. This can be solved by using special optical passive filters that are designed to compensate for the gain variation of the EDFA.
  • WDM wavelength division multiplexing
  • Figure 2 illustrates the basic principle of an optical amplifier 100 of the present invention.
  • a plurality of inputs and outputs are described - that is a multi-port amplifier is described.
  • this invention applies to single or multiple input and/or single or multiple output systems.
  • a multi-port optical amplifier 100 comprises an input fibre array 10 for carrying input signal beams, coupled to an input fibre collimator array 11 , which converts the input signal beams into collimated beams 12.
  • a VCSEL array 14 generates an array of pump beams 15 perpendicular to the signal beam direction.
  • the pump beams 15 and the collimated signal beams 12 are combined using a WDM beam combiner 13.
  • the combined beams 16 output from the combiner 13 are then coupled into an output array 18 of rare-earth doped fibres via a fibre focuser array 17.
  • the gain of each output port of the fibre array 18 is controlled by the amount of VCSEL pump beam 15 coupled into that particular port.
  • the amount of pump power coupled into an output port can be adjusted by adjusting the current that drives the relevant portion of the VCSEL array 14 associated with that particular output port.
  • a VCSEL 20 is used as a pump.
  • the VCSEL 20 generates a diverging optical beam 21.
  • the divergence angle is less than 5°.
  • a VCSEL microlens 22 is integrated with the VCSEL 20 to collimate the
  • the VCSEL 20 is flip-chip bonded with an Ultra-Thin
  • UTS Semiconductor
  • the wavelength of the anti- reflecting coating is selected so that a free-space input signal beam 26 incident at the edge 29 from a horizontal direction - that is perpendicular to the VCSEL beam
  • a microlens 27 is etched directly into the glass substrate 25, and its focal length and position optimized, so that the VCSEL beam 21 and an input signal beam 26 into the core of the EDFA 28, wherein the pump beam is absorbed, and the signal beam is amplified.
  • the VCSEL beam 21 emitting from the VCSEL 20 is efficiently coupled to the doped optical fibre 28.
  • the coupling efficiency of the VCSEL 20 to the EDFA 28 is maximized by optimising the position and the focal length of the integrated VCSEL microlens 22.
  • the coupling efficiency of the input signal beam 26 to the EDFA 28 is maximized by optimising position and focal length of the integrated glass microlens 27.
  • the EFDA gain is proportional to the amount of pump beam power coupled into the EFDA 24. It is therefore possible to adjust the amount of VCSEL beam 21 coupled into the EDFA 28 so that arbitrary gain is achieved by controlling the amount of pump beam coupled into the EFDA 28. To achieve maximum pumping efficiency, the lengths of the doped fibers are optimized to provide the maximum possible small-signal gain at the maximum available VCSEL pump power.
  • a single VCSEL 20 and EFDA 28 have been described above with respect to Figure 3. However, in a preferred embodiment of the present invention, a VCSEL array and an EFDA array can be used.
  • VCSEL arrays can generate more than 100 mW of optical power per VCSEL element.
  • 70 mW of pump power can be coupled into each output port - that is port of the EFDA array.
  • the length of the doped fibre in the array is optimized and the optical signal power is small ( ⁇ -10 dBm)
  • more than 13 dBm of output optical signal power can be obtained over the optical telecommunications C band (1530 - 1560 nm).
  • gain-flattened and gain-clamped EDFA's can be used in the present invention.
  • VCSEL and EFDA arrays can be used.
  • Figure 4 illustrates an embodiment of an optical amplifier 100 of the invention using such arrays.
  • the optical amplifier 100 comprises a 2D input fibre array 30 with a 2D input microlens array 31 etched directly into a glass substrate 32 in order to collimate input signal beams 34 from the input fibre array 30.
  • the glass substrate 32 has a V-groove shape 41 with a left edge 33 is cleaved at 45° and coated with an anti- reflective coating to pass a large proportion of the input signal beams 34 through into the glass substrate 32, while reflecting a low-power monitoring signal beam
  • the photodetector array 40 is bonded to a flip chip photodetector array 40, for monitoring the input signal beam - as will be discussed in more detail below.
  • the photodetector array 40 is bonded to a
  • UTS chip 60 that integrates a pump photodetector array (not shown) for pump beam power monitoring, and is attached to the glass substrate 32.
  • V-groove 41 can be free- space or any index matching glass.
  • the glass substrate 32 can be replaced by a sapphire substrate.
  • Sapphire has attractive properties that make it a competent material that can be grown to arbitrary shape: including lens etching with close dimensional tolerances and special surface finishes.
  • a microlens array 37 At the output of the glass substrate 32, there is provided a microlens array 37.
  • the microlens array 37 is used focus the signal beams 34 and couple them into the output ports of an EDFA array 38, and is also directly etched onto the glass substrate 32.
  • the microlens arrays 31 , 37 can be replaced by diffractive optical element relays.
  • the EFDA array 38 comprises rare- earth doped fibre collimator waveguides - either erbium-doped alumino-silicate or praseodymium-doped flouride.
  • the fibres can be either core-pumped or cladding- pumped.
  • a 2D VCSEL array 50 is used to supply the pump beams 39 for input to various ports of the EFDA array 38.
  • the pitch of the VCSEL array 50, the input microlens array 31 , the photodetector array, the output microlens array 37, the input fibre array 30, and the EDFA array 38 must be equal.
  • the VCSEL array 50 can operate in a transverse single mode, where the EFDA array fibres are core pumped. In an alternative embodiment, the VCSEL array 50 can operate in multi-mode for cladding-pumped EFDA array fibres.
  • an external cavity resonator (not shown) can be used in conjunction with the VCSEL array 50 to provide higher effective active diameter and improved loss discrimination between transverse modes.
  • the detected signal beam and pump beam powers are supplied from the respective photodetector arrays to an electronic processor 46, via a detected signal power bus 42 and a detected pump power bus 44.
  • the processor 46 is operable to estimate the required pump powers - for desired EDFA gains - and to generate the driving currents 48 for the various VCSEL elements of the VCSEL array 50.
  • the VCSEL array 50 is operated in the active region, the relationship between the output pump power and input driving current is linear. This means that the estimation of the required VCSEL driving current requires one multiplication operation and one addition operation.
  • the EDFA gain can be calculated from the pump power via a simple expression.
  • the EDFA gain depends non- linearly on the input signal power as well as the pump beam power. This requires a complex iterative algorithm and a storage medium to accurately estimate the required VCSEL driving current for an EDFA gain target.
  • the method for controlling the gains comprises the steps of measuring the power of pump beams generated by the VCSEL array 50 using the photodetector array integrated in the UTS chip 60, and deriving a first signal representative thereof, measuring the power of input optical signals using the photodetector array 40, and deriving a second signal representative thereof.
  • the processor 46 is then operable to estimate the signal gain, based on the measured input signal power and pump power, and to derive a third signal representative of the difference between the measured signal gain and the desired gain.
  • this value of this representative third signal becomes nonzero, and enables a VCSEL current increment needed to maintain the desired signal gain to be calculated.
  • the algorithm uses the third signal representative to calculate the corresponding VCSEL current increment, ⁇ l, necessary to retune the gain to the desired value.
  • the processor 40 is operable to process the first, second and third signals, and to generate a VCSEL array 50 driving current profile in response to the processed first, second and third signals; and, further, to control the generation of driving current profile to achieve the desired output power for the pump beanr
  • FIG. 5 An alternative embodiment, shown in Figure 5, utilises the same concept used in Figures 4, except that the signal monitoring photodetector array 125 is flip-chip bonded to the optical substrate so that it is opposite parallel to the VCSEL array 101. This eliminates free-space beam propagation and allows the device to be more practical.
  • the in-fibre optical signals are collimated by a microlens array 119, etched directly into the optical substrate. Small portions ( ⁇ 5%) of the collimated signal beams 121 are reflected by the 45° coated edge 122 and photodetected by the flip-chip bonded signal-monitoring photodetector array 125.
  • the high portions of the signal beams are coupled to the output erbium-doped fibre ports via an output microlens array 115 etched directly into the optical substrate.
  • the approach of coupling and monitoring the pump beams into the output EFD ports is similar to that described in the preceding section and illustrated in Figure 4.
  • This optical amplifier 200 provides high output power and low noise, making it possible to cascade a multiplicity of optical amplifiers carrying high channel counts at high bit rates.
  • high-level of electronic and optical integration for efficient automatic gain control via software can be embedded.
  • a digital control system can be implemented, which features an easy-to-use interface and command set. Integration of the amplifier is achieved using a standard +5 VDC and GND power lines and a RS-232 interface.
  • Gain flattening filters can be integrated with the doped fibres to provide flat gain across the entire band.
  • the gains of the individual ports can independently be adjusted to support a wide range of fibre span lengths and optical network components losses.
  • the amplifier can be configured via simple software commands - using the method described above
  • Built-in monitoring can be provided by the bonded photodetector array 125, and the pump beam photodetector array integrated in the UTS chip 108.
  • volume production The amplifier of preferred embodiments of the present invention is suitable for volume production.

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  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Lasers (AREA)
  • Optical Couplings Of Light Guides (AREA)

Abstract

L'invention concerne un amplificateur optique (200) présentant des moyens (117) d'entrée et des moyens (101) de production de faisceau de pompage. Des moyens (113) de guide d'onde, tels que des fibres dopées à l'Erbium, reçoivent le signal d'entrée et émettent en sortie des signaux amplifiés. Ledit amplificateur (200) peut présenter plus de 64 ports entrée/sortie, et les moyens (101) de production de pompage peuvent comprendre un réseau de lasers émetteurs à surface de cavité verticale. Le gain peut être commandé par la surveillance des signaux d'entrée et des puissances de pompage, et par le réglage de la pompe dirigeant les profils de courant selon l'invention.
EP03769046A 2002-10-30 2003-10-30 Amplificateur optique multiports a reseau de pompe vcsel et commande de gain Withdrawn EP1563618A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
AU2002952347A AU2002952347A0 (en) 2002-10-30 2002-10-30 Optical amplifier
AU2002952347 2002-10-30
PCT/AU2003/001439 WO2004040810A1 (fr) 2002-10-30 2003-10-30 Amplificateur optique multiports a reseau de pompe vcsel et commande de gain

Publications (1)

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EP1563618A1 true EP1563618A1 (fr) 2005-08-17

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EP03769046A Withdrawn EP1563618A1 (fr) 2002-10-30 2003-10-30 Amplificateur optique multiports a reseau de pompe vcsel et commande de gain

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EP (1) EP1563618A1 (fr)
JP (1) JP2006505117A (fr)
AU (1) AU2002952347A0 (fr)
WO (1) WO2004040810A1 (fr)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120170933A1 (en) 2010-12-29 2012-07-05 Christopher Doerr Core-selective optical switches
US9103987B2 (en) 2010-12-29 2015-08-11 Alcatel Lucent Optical amplifier for multi-core optical fiber
JP2013235969A (ja) * 2012-05-09 2013-11-21 Furukawa Electric Co Ltd:The 光ファイバ接続構造、光増幅器の励起光制御方法
JP2014116466A (ja) * 2012-12-10 2014-06-26 Nippon Telegr & Teleph Corp <Ntt> 光ファイバ増幅器
JP2015167158A (ja) * 2014-03-03 2015-09-24 日本電信電話株式会社 マルチコアファイバ増幅器

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5301201A (en) * 1993-03-01 1994-04-05 At&T Bell Laboratories Article comprising a tunable semiconductor laser
US6407854B1 (en) * 2000-03-06 2002-06-18 Ditech Corporation Fiber amplifier with fast transient response and constant gain
US6778582B1 (en) * 2000-03-06 2004-08-17 Novalux, Inc. Coupled cavity high power semiconductor laser
KR100346221B1 (ko) * 2000-09-06 2002-08-01 삼성전자 주식회사 어븀첨가 광섬유 증폭기의 이득 제어 장치 및 방법
US6888668B2 (en) * 2001-12-13 2005-05-03 Intel Corporation Optical amplifier with multiple wavelength pump

Non-Patent Citations (1)

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Title
See references of WO2004040810A1 *

Also Published As

Publication number Publication date
JP2006505117A (ja) 2006-02-09
WO2004040810A1 (fr) 2004-05-13
AU2002952347A0 (en) 2002-11-14

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