CN1214480A - Apparatus which includes virtually imaged phased array (VIPA) in combination with wavelength splitter to demultiplex wavelength division multiplexed (WDM) light - Google Patents

Apparatus which includes virtually imaged phased array (VIPA) in combination with wavelength splitter to demultiplex wavelength division multiplexed (WDM) light Download PDF

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CN1214480A
CN1214480A CN98119460A CN98119460A CN1214480A CN 1214480 A CN1214480 A CN 1214480A CN 98119460 A CN98119460 A CN 98119460A CN 98119460 A CN98119460 A CN 98119460A CN 1214480 A CN1214480 A CN 1214480A
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wavelength
vipa
output
light
demodulation multiplexer
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CN1154865C (en
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白崎正孝
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Fujitsu Ltd
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Fujitsu Ltd
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    • 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
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
    • G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
    • G02B6/29304—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by diffraction, e.g. grating
    • G02B6/29305—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by diffraction, e.g. grating as bulk element, i.e. free space arrangement external to a light guide
    • G02B6/29311—Diffractive element operating in transmission
    • 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
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
    • G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
    • G02B6/29346—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by wave or beam interference
    • G02B6/29358—Multiple beam interferometer external to a light guide, e.g. Fabry-Pérot, etalon, VIPA plate, OTDL plate, continuous interferometer, parallel plate resonator
    • 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
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
    • G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
    • G02B6/29379—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means characterised by the function or use of the complete device
    • G02B6/2938—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means characterised by the function or use of the complete device for multiplexing or demultiplexing, i.e. combining or separating wavelengths, e.g. 1xN, NxM
    • 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
    • H04B10/25—Arrangements specific to fibre transmission
    • H04B10/2507—Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion
    • H04B10/2513—Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion due to chromatic dispersion
    • H04B10/25133—Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion due to chromatic dispersion including a lumped electrical or optical dispersion compensator

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Optical Communication System (AREA)
  • Optical Integrated Circuits (AREA)

Abstract

An apparatus which combines a virtually imaged phased array (VIPA) with a demultiplexer, to provide a large bandwidth, high resolution wavelength demultiplexer. Generally, a VIPA is a device which receives an input light having a respective wavelength within a continuous range of wavelengths, and causes multiple reflection of the input light to produce self-interference and thereby form an output light. The output light is spatially distinguishable from an output light formed for an input light having any other wavelength within the continuous range of wavelengths. The apparatus combines the VIPA with a demultiplexer, such as a diffraction grating.

Description

Wdm light beam is carried out the device of demultiplexing
The present invention relates to a kind of device, it comprises a virtual image phased array (VIPA), in order to a wavelength-division multiplex (WDM) light beam is carried out demultiplexing.More particularly, the present invention relates to a kind of device, it comprises one with a wavelength separator, for example a diffraction grating, the VIPA that combines allows one to have than the wdm light beam of relatively large wavelength components close to each other by demultiplexing accurately.
In optical fiber telecommunications system, use wavelength-division multiplex (mode) to come the relatively large data of transfer ratio with two-forty.More particularly, many light carriers, each all has the information modulation thereon, is combined into a wdm light beam.Subsequently, this wdm light beam is sent to a light-receiving device by an independent optical fiber.This light-receiving device is other all light carrier with this wdm light beam subdivision, makes that this other light carrier can be detected.So, a communication system just can transmit relatively lot of data on an optical fiber.
Therefore, this light-receiving device accurately the ability of this wdm light beam of subdivision will influence the performance of this communication system widely.For example, even a large amount of light carriers can be incorporated into intrafascicular going of wavelength division multiplexed light, if this light-receiving device this wdm light beam of subdivision accurately, then a kind of like this wdm light beam just can't be sent out.Correspondingly, concerning a light-receiving device, total hope contains a high-precision wavelength separator.
Fig. 1 is a figure, illustrates one as color filter wavelength separator, that use the routine of a multi-coated interference film.Referring now to Fig. 1,, on a transparent substrates 22, formed a multi-coated interference film 20.Light beam 24, it must be a parallel beam, is projected onto on the film 20 reflection repeatedly in film 20 then.The optical condition that characteristic determined by film 20 only allows a light beam with wavelength X 2 from wherein passing through.A light beam 28, it comprises that all do not satisfy the light beam of this optical condition, can not and thereby be reflected by this film 20.Therefore, a color filter that is shown in Fig. 1 can be used for one of subdivision and only comprise two wdm light beams with light carrier of different wave length λ 1 and λ 2.Unfortunately, a kind of like this color filter only depends on itself, can not separate a wdm light beam with two above light carriers.
Fig. 2 is a figure, and the special interferometer of a Fabry as the routine of a wavelength separator-Pyrrho is described.Referring now to Fig. 2,, the reflectance coating 30 and 32 of high reflectance is parallel to each other.Light beam 34, it must be a parallel beam, is projected onto on the reflectance coating 30, and reflects many times between film 30 and 32.The light beam 36 that satisfies wavelength by the optical condition that characteristic determined of the special interferometer of this Fabry-Pyrrho and be λ 2 can penetration films 32.The light beam 38 that not satisfy this wavelength that sees through condition be λ 1 is reflected.So, having two kinds of light beams of different wavelengths can be two different light beams by subdivision, and they correspond respectively to this two different wavelength.Therefore, as adopting color filter shown in Figure 1, the special interferometer of the Fabry of a routine-Pyrrho can be used for one of subdivision and only comprise two wdm light beams with light carrier of different wave length λ 1 and λ 2.Unfortunately, the special interferometer of a kind of like this Fabry-Pyrrho can not separate a wdm light beam with two above light carriers.
Fig. 3 is a figure, and a Mi Cheerxun interferometer as a wavelength separator is described.Referring now to Fig. 3,, parallel beam 40 is projected onto a half-reflecting mirror 42, and is mutually perpendicular one first light beam 44 and one second light beam 46 by subdivision.Catoptron 48 reflections first light beam 44, another piece catoptron 50 then reflects second light beam 46.Distance between half-reflecting mirror 42 and the catoptron 48, and the optical path difference of distance expression between half-reflecting mirror 42 and the catoptron 50.Be folded back half-reflecting mirror 42 by catoptron 48 beam reflected, follow by catoptron 50 reflection and the light beam that is folded back half-reflecting mirror 42 to interfere.Consequently, have all light beams 52 and 54 of wavelength X 1 and λ 2 respectively by disconnected from each other.As adopting the special interferometer of color filter shown in Figure 1 and Fabry shown in Figure 2-Pyrrho, Mi Cheerxun interferometer shown in Figure 3 can be used for subdivision and only comprise two wdm light beams with light carrier of different wave length λ 1 and λ 2.Unfortunately, a kind of like this Mi Cheerxun interferometer can not separate a wdm light beam with two above light carriers.
Might be with several color filter, special interferometer of Fabry-Pyrrho or Mi Cheerxun interferometer are combined into a huge array, make it can be from an intrafascicular light carrier of isolating additional wavelength of independent wavelength division multiplexed light.Yet a kind of like this array is expensive, poor efficiency, also produces a undesirable huge light-receiving device.
A diffraction grating or an array waveguide grating are used to separate a wdm light beam that contains two above different wave length light carriers usually.Referring now to Fig. 4,, a diffraction grating 56 has a grating surface 58.The parallel beam 60 that contains many kinds of different wave length light carriers is projected onto on the grating surface 58.All light carriers of different wave length are reflected on each step of grating surface 58 and interfere with each other.Consequently, all light carriers 62,64 and 66 with different wave length are output with different angles from diffraction grating 56, and disconnected from each other thus.
Unfortunately, diffraction grating (can only) have all light carriers of different wave length with quite little angle of divergence output.Consequently, concerning a light-receiving device, be difficult to accurately receive each optical carrier that separates by this diffraction grating.When separating wdm light beam with the quite close light carrier of a large amount of wavelength with diffraction grating, this problem especially severe that just becomes.In this case, will be extremely little by the angle of divergence that this diffraction grating produced, ≈ 0.05 degree/nanometer typically.
Also have, a diffraction grating can be subjected to the influence of the light polarization of this incident beam.Therefore, the polarization of incident beam can influence the performance of this grating.And in order to produce an accurate diffraction grating, its grating surface needs complicated manufacturing process.
Fig. 5 is a figure, and an array waveguide grating that is used to separate the routine of a wdm light beam is described.Referring now to Fig. 5,, comprises that the light beam of the light carrier of many different wave lengths is received by an inlet 68, and be separated by many waveguides 70.In the end of each waveguide 70 light exit 72 is arranged all, make that an output beam 74 is produced.All waveguides 70 have nothing in common with each other on length, and the light path of different length is provided thus.Therefore, all light beams by all waveguides 70 have the phase place that has nothing in common with each other, and when they interfere with each other when exporting 72 outputs.This interference makes all light beams with different wave length be output with different all directions.
In an array waveguide grating, can adjust its angle of divergence to a certain extent by suitably disposing all waveguides.Yet array waveguide grating can be subjected to temperature variation and other various Effect of Environmental.Therefore, temperature variation and other various environmental factors make that suitably adjusting this angle of divergence becomes difficult.
Correspondingly, a target of the present invention provides a kind of wavelength separator, and it has a kind of simple configuration, and can isolate many light carriers simultaneously from wavelength division multiplexed light is intrafascicular.
A subsidiary target of the present invention provides a kind of device, and its one of permission has quite a large amount of all light carriers close to each other or the wdm light beam of all wavelength components is able to accurately by demultiplexing.
By providing a kind of device just can realize all targets of the present invention, this device receives one and have the input beam of a wavelength separately in a continuous wavelength coverage, and produces a corresponding output beam.It spatially is distinguishable (for example, it is advanced along a different direction) that this output beam is followed the formed output beam of an input beam that has any other wavelength in this continuous wavelength coverage.
More particularly, this device receives an input beam that has a wavelength separately in a continuous wavelength scope, and wherein this device causes that the repeatedly reflection of this input beam is to produce self-interference and to form an output beam thus.It spatially is distinguishable that this output beam is followed the formed output beam of an input beam that has any other wavelength in this continuous wavelength scope.This device can be called as a virtual image phased array (VIPA).
And, by being provided, a kind of device just can realize all targets of the present invention, and this device is followed a wavelength separator with a VIPA, or " demodulation multiplexer ", and for example a diffraction grating is combined.More particularly, this VIPA receives an input beam and produces a corresponding output beam that blazes abroad from this VIPA.This output beam comprises all wavelength components that many kinds are different, for example different all light carriers.This demodulation multiplexer is all light beams of many separation with this output beam demultiplexing, and they are respectively corresponding to the different wavelength components of many kinds in this output beam.Preferably, this demodulation multiplexer has a direction of dispersing of dispersing direction perpendicular to this VIPA.In this case, can detect all light beams that separated with all optical fiber that is arranged in the grid map.
Also have, just can realize all targets of the present invention by a kind of device is provided, this device carries out demultiplexing to an input beam that contains many light beams.These are many all to have a kind of different wavelength with each root in the light beam.This device comprises first and second demodulation multiplexers.This first demodulation multiplexer is many output beams with this input beam demultiplexing, and they are respectively corresponding to many light beams in this input beam.This first demodulation multiplexer is essentially linear these the many output beams of directional divergence of dispersing along one, and each root output beam all has a different output angle.And each root output beam comprises many kinds of wavelength components.This second demodulation multiplexer is the light beam of many separation with each root output beam demultiplexing, and they are respectively corresponding to many kinds of wavelength components in output beam.This second demodulation multiplexer is essentially linear these the many all light beams that separated of directional divergence of dispersing along one, and the light beam that each root has separated all has a different output angle.The direction of dispersing of this second demodulation multiplexer is not parallel to, and preferably perpendicular to the direction of dispersing of, this first demodulation multiplexer.
From the following explanation about all embodiment in conjunction with all accompanying drawings, these and other target and advantage of the present invention will become apparent and be easier to understand, in the accompanying drawings:
Fig. 1 (prior art) is a figure, and a color filter that uses the routine of a slice multi-coated interference film is described.
Fig. 2 (prior art) is a figure, and the special interferometer of Fabry-Pyrrho of a routine is described.
Fig. 3 (prior art) is a figure, and the Mi Cheerxun interferometer of a routine is described.
Fig. 4 (prior art) is a figure, and the diffraction grating of a routine is described.
Fig. 5 (prior art) is a figure, and an array waveguide grating that is used to separate the routine of a wdm light beam is described.
Fig. 6 is a figure, and a virtual image phased array according to an embodiment of the invention (VIPA) is described.
Fig. 7 is a figure, illustrate this VIPA that is shown in Fig. 6 according to an embodiment of the invention along VII--the cross section of VII line.
Fig. 8 is a figure, the interference between all reflections (light beam) that illustrate according to one embodiment of present invention, produced by VIPA.
Fig. 9 is a figure, illustrate according to one embodiment of present invention, be shown in Fig. 6 this VIPA along VII--a cross section of VII line, in order to represent the formation of a light beam.
Figure 10 is a figure, illustrate according to one embodiment of present invention, be shown in Fig. 6 this VIPA along VII--a cross section of VII line, represent all characteristic of a VIPA in order to the inclination angle of determining input beam.
Figure 11 is a figure, illustrates according to one embodiment of present invention, follows the VIPA that light-receiving device is used.
Figure 12 is a figure, illustrates according to an additional embodiment of the present invention, with the VIPA that light-receiving device is used.
Figure 13 is a figure, and a VIPA according to still another embodiment of the invention is described.
Figure 14 is a figure, and a waveguide type VIPA according to an embodiment of the invention is described.
Figure 15 (A), 15 (B), 15 (C), 15 (D) are several figure, illustrate according to one embodiment of present invention, in order to produce a kind of method of a VIPA.
Figure 16 (A) and 16 (B) are two figure, respectively explanation according to one embodiment of present invention, with a VIPA with a demodulation multiplexer, diffraction grating for example, the top view of a kind of device of combining and side view.
Figure 17 (A) is a figure, and the relation of output angle and the wavelength of VIPA according to an embodiment of the invention is described.
Figure 17 (B) is a figure, and the relation of the output angle and the wavelength of a diffraction grating is described.
Figure 18 is a figure, and an example of the work of VIPA one diffraction instrument according to an embodiment of the invention is described.
In detail with reference to all preferred embodiments of the present invention, the example is shown in all accompanying drawings now, and wherein, identical all reference numbers are all the time corresponding to identical all elements.
Fig. 6 is a figure, and a virtual image phased array according to an embodiment of the invention (VIPA) is described.Hereinafter, noun " wavelength separator " and " virtual image phased array " or " VIPA " can be used interchangeably.
Referring now to Fig. 6,, the most handy thin glass sheet of VIPA76 is made.Incident light 77 is by lens 80, and for example a semicylindrical lens focuses on the line 78, makes incident light 77 enter VIPA76.Below line 78 is called " focal line 78 ".Incident light 77 is radially propagated from the focal line 78s, is received in the VIPA the inside.VIPA76 exports a collimated light beam 82 then, and the output angle of this light beam 82 changes along with incident light 77 wavelength change.For example, if the wavelength of incident light 77 is λ 1, then VIPA76 is according to the specific light beam 82a that wavelength is λ 1 of direction output.If the wavelength of incident light 77 is λ 2, then VIPA76 is according to the different light beam 82b that wavelength is λ 2 of direction output.If it is the wdm light beam that the light beam of λ 1 and sets of beams that wavelength is λ 2 lump together with wavelength that incident light 77 is one, then VIPA76 is simultaneously with the light beam 82a and the 82b of two separation of different directions output.Therefore, VIPA76 has produced the light beam 82a and the 82b that spatially can distinguish mutually.So, VIPA76 just can be from an intrafascicular light beam of isolating two or more carrying informations simultaneously of wavelength division multiplexed light.
Fig. 7 is a figure, and VIPA76 section along the line VII a--cross section of VII that is shown in Fig. 6 according to embodiments of the invention is described.Referring now to Fig. 7,, VIPA76 contains a kind of material 84, and for example glass has all reflectings surface 86 and 88 thereon.All reflecting surface 86 and 88 is parallel to each other, and the t at interval that is spaced.All reflectings surface 86 and 88 are typically attached to the reflectance coating on the material 84.Except one with radiation window 90 described in detail below, reflecting surface 88 has about 100% reflectivity.Reflecting surface 86 has about 95% reflectivity.Therefore, reflecting surface 86 has about 5% transmitance, make that the light central nearly 5% that incides on the reflecting surface 86 will be seen through, and about 95% light will be reflected.This reflectivity can be used according to specific VIPA at an easy rate and change.But in general, reflecting surface 86 should have the reflectivity less than 100%, so that the part in the incident light is seen through.
Reflecting surface 88 has a radiation window 90 thereon.Radiation window 90 allows light beam to see through, and preferably reflectivity is zero, perhaps has a low-down reflectivity.Radiation window 90 receives incident light 92, makes incident light 92 to be received between all reflectings surface 86 and 88 and to be reflected.
Because Fig. 7 represents line segment VII--the cross section of VII along Fig. 6, so the focal line 78 among Fig. 6 shows as one " point " in Fig. 7.Then, incident light 92 is radially propagated from the focal line 78s.And as shown in Figure 7, focal line 78 is located on the reflecting surface 86.Though concerning focal line 78 and do not require that it is positioned on the reflecting surface 86, the displacement meeting of focal line 78 causes the little variation of the characteristic of VIPA76.
As shown in Figure 7, incident light 92 enters material 84 by a regional A0 in radiation window 90, and here all some P0 represents all frontier points of regional A0.
Because the reflection of reflecting surface 86, nearly less than 5% light transmission reflecting surface 86, promptly by the defined emergent light Out0 of light R0, and about incident light 92 more than 95% face 86 that is reflected reflects, and is projected onto on the regional A1 of reflecting surface 88.All some P1 represents all frontier points of regional A1.
After the regional A1 from reflecting surface 88 reflected away, incident light 92 advanced to reflecting surface 86 and penetration face 86 partly, promptly by the defined emergent light Out1 of light R1.So, as shown in Figure 7, incident light 92 has experienced repeatedly reflection between all reflectings surface 86 and 88, and wherein (light beam) whenever once also causes an outgoing beam separately therefrom to see through from reflecting surface 86 reflections.Therefore, for example, whenever incident beam 92 reflects from regional A2, A3 and A4 on the reflecting surface 88, incident beam 92 just reflects from reflecting surface 86, and produces all outgoing beam Out2, Out3 and Out4 respectively.All some P2 represents all frontier points of regional A2, and all some P3 represents all frontier points of regional A3, and all some P4 represents all frontier points of regional A4.Outgoing beam Out2 is by light R2 definition, and outgoing beam Out3 is by light R3 definition, and outgoing beam Out4 is defined by light R4.Though Fig. 7 only illustrates all outgoing beam Out1, Out2, in fact Out3 and Out4 will have more outgoing beam, and this depends on the power of incident beam 92 and the reflectivity of all reflectings surface 86 and 88.
As with described in detail below, all outgoing beams interfere with each other to produce a light beam as output beam.The direction of outgoing beam changes according to the wavelength of incident beam 92.
Fig. 7 illustrates that incident beam 92 has only a kind of example of wavelength.Yet if this input beam contains multi-wavelength's (wdm light beam for example, it contains a plurality of light carriers, wherein each all has different wavelength), this input beam will be reflected in the same way.Yet,, will form many light beams respectively corresponding to many light carriers.Each root light beam will be from this VIPA to be different from the angle output of other all light beams.
Fig. 8 is a figure, and the interference between all reflections (light beam) that produced by a VIPA is described according to one embodiment of present invention.Referring now to Fig. 8,, from face 88 reflections that are reflected of the light beam of focal line 78, face 86 reflections then are reflected.As previously mentioned, reflecting surface 88 has about 100% reflectivity, and, therefore, play the effect of mirror in fact.Consequently, outgoing beam Out1 can analyze with optical means, and all seemingly reflectings surface 86 and 88 do not exist like that, and outgoing beam Out1 is from focal line I 1Send.Similarly, all emergent light Out2, Out3, Out4 also can analyze with optical means, and they are respectively from all focal line I seemingly 2, I 3And I 4Send like that.All focal line I 1, I 2, I 3And I 4All be this focal line I 0The virtual image.
Therefore, as shown in Figure 8, focal line I 1With focal line I 0Between distance be 2t, t equals the distance between all reflectings surface 86 and 88 here.Similarly, the follow-up focal line of each root is all stayed close the distance that the focal line in front that is close to keeps 2t.Therefore, focal line I 2Leave focal line I 1Distance be 2t.And the follow-up each time multiple reflection between all reflectings surface 86 and 88 all produces an outgoing beam, it come than previous outgoing beam in the brightness a little less than.Therefore, outgoing beam Out2 come than outgoing beam Out1 in the brightness a little less than.
As shown in Figure 8, overlap each other from all outgoing beams of all focal lines and interfere with each other.And, all focal line I 1, I 2, I 3, and I 4All be focal line I 0The virtual image, and, therefore, all emergent light Out0, Out1, Out2, Out3 and Out4 are at all focal line I 0, I 1, I 2, I 3And I 4The position, have identical optical phase.Therefore, this interference produces a light beam, and it is advanced according to a specific direction that depends on the wavelength of input beam 92.
VIPA according to above-mentioned all embodiment of the present invention has the intensified condition as the VIPA design characteristics.This intensified condition increases the interference between all outgoing beams so that form a light beam.The intensified condition of this VIPA is represented by following equation (1):
2t×cosφ=mλ
φ represents that λ represents the wavelength of this input beam from the direction of propagation perpendicular to the measured light beam of the straight line (starting at) on the surface of all reflectings surface 86 and 88 in the formula, and t represents the distance between all reflectings surface 86 and 88, and m represents an integer.
Therefore, if t keeps constant and m is assigned with a specific numerical value, then the wavelength that is formed by input beam is that the direction of propagation of this light beam of λ just can be determined.
More particularly, input beam is radially dispersed with a specific angle from focal line 78.Therefore, the input beam with identical wavelength will be advanced from the focal line 78s along many different directions, and be reflected between all reflectings surface 86 and 88.The feasible light beam of advancing along a specific direction of the intensified condition of this VIPA is strengthened by the interference of outgoing beam, so that form a light beam, its direction is corresponding to the wavelength of this input beam.The light beam that different directions beyond the desired specific direction of this intensified condition is advanced will be weakened because of the interference of all outgoing beams.
And if this input beam has many kinds of different wave lengths, then this intensified condition will form a different light beam for each wavelength in this input beam.Each root light beam will have a kind of different wavelength.Therefore, this VIPA can receive a wdm light beam, and produces the many light beams that navigate on different directions, and they are corresponding to the various wavelength of this wdm light beam.
Fig. 9 is a figure, a light beam that illustrates according to one embodiment of present invention, forms by VIPA76, and expression is along a cross section of the line segment VII among Fig. 6.More particularly, Fig. 9 explanation, VIPA76 can form many light beams, and wherein each root light beam all has a different direction of propagation of depending on the wavelength of this input beam.
Referring now to Fig. 9,, the input beam with many kinds of wavelength is radially dispersed from the focal line 78s, makes this light beam be reflected between all reflectings surface 86 and 88.Suppose that this input beam comprises having 3 kinds of light beams of different wavelengths.Therefore, the light beam of each wavelength will be from the focal line 78s along many different directional divergences.The intensified condition of VIPA76 makes that have the identical wavelength light beam that is navigated on different all directions in the light beam of a specific direction that walks abreast into strengthens, so that form a light beam.The latter has the direction corresponding to this input beam wavelength.Therefore, for example, have wavelength X 1 and start at the light beam that the light beam of propagating along direction θ 1 will be navigated on different all directions from focal line 78 and strengthen, and will form a light beam LF1 with direction of propagation θ 1.Similarly, have wavelength X 2 and light beam that the light beam propagated along direction θ 2 from the focal line 78s will be navigated on different all directions is strengthened, and will form a light beam LF2 with direction of propagation θ 2.Equally, have wavelength X 3 and light beam that the light beam propagated along direction θ 3 from the focal line 78s will be navigated on different all directions is strengthened, and will form a light beam LF3 with direction of propagation θ 3.
As mentioned above, should satisfy equation (1), make between all outgoing beams, to increase and interfere so that form a light beam.And the thickness t of material 84 is preferably fixed.Therefore, the ranges of incidence angles of input beam should be set like this, makes input beam to enter VIPA76 with a direction of propagation φ that can satisfy equation (1).More particularly, the direction of propagation of input beam can be fixed, can be fixed between all reflectings surface 86 and 88 apart from t, and the wavelength of input beam can be determined in advance.Therefore, can be determined at the special angle of the light beam of each the wavelength institute outgoing in the input beam, and the intensified condition of VIPA76 can be satisfied.
And, since input beam from the focal line 78s along many different direction radiation, can be sure of that input beam will be along an angular spread that can satisfy this intensified condition.
Figure 10 is a figure, and the along the line section VII of this VIPA that is shown in Fig. 6 is described--a cross section of VII, expression according to one embodiment of present invention, VIPA is in order to determining the incident angle of input beam, or all characteristics at inclination angle.
Referring now to Figure 10,, input beam 92 is collected by a cylindrical lens (not shown), and is focused in focal line 78.As shown in figure 10, input beam 92 is covered with an area with the width that equals " a " on the radiation window 90.Input beam 92 is after reflecting surface 86 is reflected once, and input beam 92 is projeced into reflecting surface 88, and is covered with an area with the width that equals " b " on the reflecting surface 88.And as shown in figure 10, input beam 92 is advanced along an optical axis 94, and optical axis 94 is θ 1 with respect to the inclination angle between the normal of reflecting surface 86.
This inclination angle [theta] 1 should be set like this, so that when input beam 92 is incident in this VIPA, prevents that it from advancing outside material 84 by radiation window 90, and is reflected after face 86 reflects first at it, prevents that input beam 92 from navigating on outside the reflecting surface 88.In other words, this inclination angle [theta] 1 should be set like this, makes input beam 92 keep the state of a kind of " being captured " between all reflectings surface 86 and 88, and can not escape by radiation window 90.Therefore, navigate on outside the material 84 by radiation window 90, should set this inclination angle [theta] 1 according to following equation (2) for fear of input beam 92:
Optical axis angle θ 1 〉=(a+b)/4t
Therefore, as Fig. 6-shown in Figure 10, all embodiment of the present invention comprise a VIPA who receives input beam, and this input beam has a wavelength separately that is in the continuous wavelength coverage.This VIPA causes that the repeatedly reflection of this input beam is to produce self-interference and to form an output beam thus.It spatially is differentiable that this output beam is followed formed another root output beam of an input beam that has any other wavelength within continuous wavelength coverage.For example, Fig. 7 illustrates an input beam 92, and it has experienced repeatedly reflection between all reflectings surface 86 and 88.This repeatedly reflection produces many outgoing beam Out1, Out2, and Out3 and Out4, they interfere with each other to produce a light beam (all light beam LF1 for example shown in Figure 9, LF2 or LF3).
" self-interference " is a noun, show to interfere to occur between many light or the light beam, and they all derives from same light source.Therefore, all outgoing beam Out0, Out1, Out2, Out3 and Out4 are called as the self-interference of input beam 92, because all outgoing beam Out0, Out1, Out2, Out3 and Out4 all derive from same light source (that is exactly input beam 92).
According to the abovementioned embodiments of the present invention, an input beam can have any wavelength that is in the continuous wavelength scope.Therefore, this input beam is not limited to have a wavelength, and the latter is a selected numerical value in the discrete numerical range.
Also have, according to the abovementioned embodiments of the present invention, the output beam that input beam produced that in a continuous wavelength scope, has a specific wavelength, with another root output beam spatially is differentiable, and the latter produces when this input beam has the different wavelength of of being in the continuous wavelength scope.Therefore, for example as shown in Figure 6, when input beam 77 had various different wave length in a continuous wavelength scope, the direct of travel of this light beam 82 (that is exactly a kind of " spatial character ") was different.This work can compare with the wavelength separated device of the routine that is shown in Fig. 1-Fig. 3, here, output beam corresponding to two kinds of different wave lengths of input beam spatially is differentiable, but can not produce a spatially differentiable output beam at each wavelength in the continuous wavelength scope of this input beam.For example, in color filter shown in Figure 1, all the intrafascicular light carriers of a wavelength division multiplexed light that do not contain wavelength X 2 will be outputted as light beam 28.
Figure 11 is a figure, illustrate one according to one embodiment of present invention, with the VIPA that light-receiving device is used.Referring now to Figure 11,, laminated reflective film 96 and 98 is applied to one and makes, has thickness t with glass, for example the both sides of 100 microns parallel-plate 100.Parallel-plate 100 preferably has the thickness that is in 20 to 2000 micrometer ranges.Reflectance coating 96 and 98 inteferometer coating preferably multilayer, high reflectance.
The reflectivity of reflectance coating 98 is about 100%, and the reflectivity of reflectance coating 96 is about 95%.Yet the reflectivity of reflectance coating 96 is not limited to 95%, and it can be a different numerical value, as long as there are enough light quantities to reflect from reflectance coating 96, make and can take place repeatedly to reflect between all reflectance coatings 96 and 98 to get final product.Preferably, the reflectivity of reflectance coating 96 is in 80% to than in 100% low several percentage points the scope.And the reflectivity of reflectance coating 98 is not limited to 100%, but should be enough high, makes repeatedly reflection can take place between all reflectance coatings 96 and 98.
Radiation window 102 receives input beams, and is located on the identical surface of the heel-tap reflex film 96 of parallel-plate 100.Can on the surface of parallel-plate 100, form radiation window 102 with a film with reflectivity of about 0%.As shown in figure 11, straight line preferably of the border between radiation window 102 and reflectance coating 96.
This input beam from, for example, optical fiber (not shown) output, and received by a collimation lens 106.Collimation lens 106 is converted to parallel beam 104 with this input beam, and the latter is received by a cylindrical lens 108.Cylindrical lens 108 focuses on focal line 110 on the reflectance coating 98 with parallel beam 104, certain that perhaps focuses on parallel-plate 100 the insides a bit on.So, input beam enters parallel-plate 100 via radiation window 102.
An inclination angle is arranged between the normal of the optical axis of input beam with respect to reflectance coating 96, make input beam after entering parallel-plate 100, can not escape by radiation window 102.Therefore, this inclination angle is set according to top equation (2).
In case enter parallel-plate 100, this input beam is the repeatedly reflection of (for example, shown in Fig. 7) experience between all reflectance coatings 96 and 98.Input beam on reflectance coating 96 every incident once, nearly 95% light quantity is reflected to reflectance coating 98, and nearly 5% light quantity penetration film 96 is to form an outgoing beam (for example, being shown in the outgoing beam Out1 of Fig. 7).Repeatedly reflection between all reflectance coatings 96 and 98 causes many outgoing beams to be formed.These many outgoing beams interfere with each other, and to form a light beam 112, the wavelength of this input beam is depended in its direction of propagation.
Light beam 112 is collected by lens 114 subsequently, and it focuses on a bleeding point with light beam 112.Corresponding to the different wave length of input beam, this bleeding point moves along straight line path 116.For example, along with the wavelength increase of input beam, this bleeding point is mobile at a distance along straight line path 116.Many light-receiving devices 118 are arranged on the straight line path 116, so that receive the light beam 112 of this focusing.Therefore, each light-receiving device 118 can be so positioned, so that receive a light beam corresponding to a specific wavelength.
By means of control between all reflectance coatings of this VIPA or reflecting surface apart from t, the phase differential of the folded light beam between all reflectance coatings or reflecting surface can be moved a predetermined quantity, realizes the good resistibility to environmental factor thus.And, only little variation of experience on optical characteristics of the above-mentioned all embodiment of the present invention, the latter is depended on optical polarization.
Figure 12 is a figure, illustrates according to an additional embodiment of the present invention, one with the VIPA that light-receiving device is used.This VIPA that is shown in Figure 12 is similar to the VIPA that is shown in Figure 11, and the reflectivity of different is all reflectance coatings 96 and 98 is reversed.More particularly, in being shown in this VIPA of Figure 12, reflectance coating 98 has about 95% reflectivity, and reflectance coating 96 has about 100% reflectivity.As shown in figure 12, by means of the interference of all outgoing beams that pass through reflectance coating 98, form light beam 112.Therefore, this input beam enters a side of parallel-plate 100, and light beam 112 is formed at opposite one side of parallel-plate 100.On the other hand, this VIPA that is shown in Figure 12 works in and the similar mode of this VIPA that is shown in Figure 11.
Figure 13 is a figure, and a VIPA according to still another embodiment of the invention is described.Referring now to Figure 13,, a flat board 120 of being made by for example glass has all reflectance coatings 122 and 124 thereon.Reflectance coating 122 has and is higher than 95% but be lower than 100% reflectivity.Reflectance coating 124 has about 100% reflectivity.Radiation window 126 has about 0% reflectivity.
Input beam 128 focuses on a focal line 129 by radiation window 126 by cylindrical lens 130.Focal line 129 is positioned on the surface of flat board 120 of the reflectance coating 122 of applying ointment or plaster.Therefore, focal line 129 comes down to focus on a line on the reflectance coating 122 by radiation window 126.The width of focal line 129 can be called as input beam 128 " beam waist ", because it is focused on by cylindrical lens 130.Therefore, this embodiment of the present invention as shown in figure 13 focuses on the beam waist of input beam 128 on dull and stereotyped 120 the distance surface far away (that is exactly to post that surface of reflectance coating 122 thereon).By beam waist being focused on the distance surface far away of flat board 120, this embodiment of the present invention has reduced at (ⅰ) and the possibility that overlaps (ⅱ), here (ⅰ) is meant in dull and stereotyped 120 lip-deep radiation windows 126 and is transfused to the zone that light beam 128 is covered, because it (is for example advanced by radiation window 126, be shown in the zone " a " of Figure 10), (ⅱ) be meant when input beam 128 be reflected film 124 first reflex time reflectance coating 124 be transfused to the zone (for example, being shown in the zone " b " of Figure 10) that light beam 128 is covered.People wish to reduce so overlapping so that guarantee the works fine of this VIPA.
In Figure 13, the optical axis 132 of input beam 128 has a little inclination angle [theta].At reflectance coating 122 reflex time first, 5% light transmission reflectance coating 122, and after beam waist, disperse, 95% light is reflected to reflectance coating 124.After the film that is reflected reflected first, this light beam projected reflectance coating 122 once more, but it is the displacement of d that quantity has taken place.Then, 5% light transmission reflectance coating 122.In a kind of similar mode, as shown in figure 13, this light beam is the many paths with constant interval d by subdivision.On each paths, this light beam forms certain shape, makes this light beam disperse from the virtual image 134 of beam waist 129.The virtual image 134 is positioned with constant interval 2t perpendicular to this dull and stereotyped straight line along one, and t is dull and stereotyped 120 thickness here.In the virtual image 134, the position of this beam waist is self aligned, and does not need to adjust other position.Subsequently, the light beam of dispersing from the virtual image 134 interferes with each other, and forms collimated light beam 136, and its direction of propagation changes along with the wavelength of input beam 128.
Light path be spaced apart d=2tSin θ, and the optical path difference between adjacent two light beams is 2tCos θ.The angle of divergence is proportional to the ratio of these two numerals, and this ratio is Cot θ.Consequently, compare with the wavelength separator of routine, all embodiment of the present invention produce a big significantly angle of divergence between all light beams of different light carriers.
Just as noted earlier, all embodiment of the present invention are called as one " virtual image phased array ".Be easy to find out that noun " virtual image phased array " originates from the formation of the array of a virtual image 134 from Figure 13.
Figure 14 is a figure, and a kind of waveguide type VIPA according to an embodiment of the invention is described.Referring now to Figure 14,, light beam 138 is exported from an optical fiber (not shown), and a waveguide 140 that is set on the substrate 142 receives.Waveguide 140 is, for example, and lithium niobate.Light beam 138 contains all optical signallings that are modulated on the many light carriers with different wave length.
Because light beam 138 is dispersed width from optical fiber output so it has one.Therefore, a collimation lens 142 is converted to parallel beam with light beam 138.Then, this parallel beam is collected by a cylindrical lens 144, and focuses on a focal line 146.Subsequently, this light beam is radiated a VIPA148 from focal line 146 by a radiation window 150.
VIPA148 contains all reflectance coatings 152 and 154 that are positioned on the parallel-plate 156.Reflectance coating 154 is positioned at a side of parallel-plate 156, and reflectance coating 152 and radiation window 150 then are positioned at the opposite side of parallel-plate 156.Reflectance coating 152 has about 100% reflectivity, and reflectance coating 154 then has the reflectivity less than 100%.Be output to the relative side of parallel-plate 156 and radiation window 150 by 156 beam reflected 158 of parallel-plate.
If input beam 138 comprises many kinds of wavelength, then will form many light beams 158, they are advanced along different directions, and this depends on all wavelength of input beam 138.The light beam 158 that is formed by VIPA148 is focused on different Zhu Dianshang by lens 160, and this depends on the direction of propagation of light beam 158.Therefore, as shown in figure 14, on different all bleeding points, will form respectively and have all wavelength X 1, all light beam 158a, 158b and the 158c of λ 2 and λ 3.
On each bleeding point, be provided with many and receive waveguide 162.Each receives waveguide 162 and derives an optical signalling and a corresponding light carrier with single wavelength.Therefore, can receive many light beams simultaneously, and send out by different all channels.Each receives waveguide 162 all has one to be arranged at the light-receiving device (not shown) of the correspondence of level thereafter.This light-receiving device is an optical diode typically.Therefore, handled by (further) after being detected by each light that receives waveguide 162 derivation by corresponding light-receiving device.
Figure 15 (A), 15 (B), 15 (C) and 15 (D) illustrate according to one embodiment of present invention, in order to the figure of the method that produces a VIPA.
Referring now to Figure 15 (A),, a parallel-plate 164 is preferably made by glass, and demonstrates the good depth of parallelism.With vacuum evaporation, ion sputtering or other similar approach, form reflectance coating 166 and 168 in the both sides of parallel-plate 164.All reflectance coatings 166 and 168 one of them have reflectivity near 100%, the another side reflectance coating then has and is lower than 100% and preferably be higher than 80% reflectivity.
Referring now to Figure 15 (B),, all reflectance coatings 166 and 168 one of them partly wiped off to form a radiation window 170.Figure 15 (B) shows reflectance coating 166 and is wiped off, makes to have formed radiation window 170 on a side surface at reflectance coating 166 places on the parallel-plate 164.Yet, substitute as a kind of, also can partly wipe reflectance coating 168 off, make on a side surface at reflectance coating 168 places on the parallel-plate 164, to form a radiation window.Illustrated as various embodiments of the present invention, a radiation window can be positioned at any side of parallel-plate 164.
Can realize striking off of reflectance coating with a kind of etching technics.But also can use a kind of technology of striking off of machinery, latter's expense is more cheap.Yet, if remove to strike off a reflectance coating, should process, so that make the damage of parallel-plate be minimum to parallel-plate 164 with mechanical means carefully.For example, be subjected to major injury, then because the scattering of received input beam will make parallel-plate 164 produce extra loss if form the part of radiation window on the parallel-plate 164.
Replace and form the method that reflectance coating is wiped it off then earlier; part corresponding to radiation window on the parallel-plate 164 can be shielded in advance; this part is protected in order to avoid the film that is reflected covers then, also can produce a radiation window with such method.
Referring now to Figure 15 (C),, a transparent adhesive tape 172 is applied to the part of having been wiped off reflectance coating on radiation film 166 and the parallel-plate 164.Adhesive tape 172 should produce the minimum optical loss of possibility, because it also is applied to that part that forms a radiation window on the parallel-plate 164.
Referring now to Figure 15 (D),, a transparent protection flat board 174 is applied on the adhesive tape 172, with protection reflectance coating 166 and parallel-plate 164.Because reflectance coating 172 is applied ointment or plaster to fill because of removing the sunk part that reflectance coating produces, so transparent protection flat board 174 can be set to parallel with the top surface of parallel-plate 164.
Similarly,, an adhesive tape (not shown) can be applied to the top surface of reflectance coating 168, and the dull and stereotyped (not shown) of a block protection is set in order to protect reflectance coating 168.If reflectance coating 168 has about 100% reflectivity, and does not have radiation window on the same surface of parallel-plate 164, then adhesive tape and protection are dull and stereotyped does not just need to have the transparency.
And, an anti-reflective film 176 can be applied on transparency protected dull and stereotyped 174.For example, anti-reflective film 176 can be covered transparency protected dull and stereotyped 174 and radiation window 170 on.
According to above-mentioned all embodiment of the present invention, a focal line is described to, and it is located on the side facing surfaces that enters with input beam on the parallel-plate.Yet this focal line can be in this parallel-plate the inside, on radiation window, perhaps in the front of this radiation window.
According to above-mentioned all embodiment of the present invention, can be between two reflectance coatings folded light beam, wherein the reflectivity of a reflectance coating is about 100%.Yet, also can obtain similar effects with two reflectance coatings that respectively have less than 100% reflectivity.For example, two reflectance coatings can respectively have 95% reflectivity.In this case, each face reflectance coating all has the light path that allows light transmission and cause interference.Consequently, in the both sides of all reflectance coatings this parallel-plate formed thereon, formed a light beam, its direct of travel depends on wavelength.Therefore, in different embodiments of the invention, can change various reflectivity according to required VIPA characteristic at an easy rate.
According to above-mentioned all embodiment of the present invention, a VIPA is described to, and forms by a parallel-plate or by two reflecting surfaces parallel to each other.But, and do not require this plate or all reflecting surface keeping parallelisms.
According to above-mentioned all embodiment of the present invention, a light beam that contains many kinds of wavelength can be side by side separated.Therefore, light-receiving device that is used for wavelength division multiplexing communications minification successfully.
According to above-mentioned all embodiment of the present invention, VIPA can with a wdm light beam side by side subdivision be each wavelength of this light beam.And, by changing the thickness t of this parallel-plate that forms this VIPA, just can adjust this angle of divergence.Consequently, can make this angle of divergence become enough big, make a light-receiving device can easily receive the signal that each has separated.For example, the diffraction grating of a routine needs a meticulous convex-concave surface so that obtain the big angle of divergence.Yet, prepare meticulous and convex-concave surface precision and be unusual difficulty, therefore limited the size of the angle of divergence.Compare therewith, the VIPA according to above-mentioned all embodiment of the present invention only need change the thickness of this parallel-plate, just can realize a bigger angle of divergence.
And the VIPA according to above-mentioned all embodiment of the present invention compares with the diffraction grating of a routine, can produce a bigger angle of divergence.Therefore, use can correctly receive an optical signalling according to the light-receiving device of the VIPA of above-mentioned all embodiment of the present invention, even also be like this in the various wavelength division multiplexing communications (system) of realizing senior multiplexed process.Also have, a kind of like this light-receiving device has quite simple structure, and also is comparatively cheap on producing.
According to above-mentioned all embodiment of the present invention, a VIPA uses repeatedly reflection, and keeps a constant phase differential between all interfering beams.Consequently, all characteristics of this VIPA are stable, have reduced the changes in optical properties that causes because of polarization thus.Compare therewith, the diffraction grating of a routine will stand undesirable (characteristic) that the polarization owing to input beam causes to be changed.
And, to compare with an array waveguide grating, a kind of simpler structure of VIPA needs according to above-mentioned all embodiment of the present invention obtains stable optical characteristics and to the resistibility of changes in environmental conditions.
Above-mentioned all embodiment of the present invention are described to, provide mutually between " spatially differentiable " all light beams." spatially differentiable " refers to, and all light beams spatially can be distinguished.For example, if different all light beams are collimated and advance by different all directions, perhaps be focused in different all positions, then they spatially are differentiable.But the present invention does not plan to be confined to these strict examples, and has many additive methods to make all light beams spatially can distinguish mutually.
A VIPA has one by the determined corresponding Free Spectral Range of the thickness t between all reflectings surface of this VIPA (thickness t between all reflectings surface 86 and 88 for example shown in Figure 7).When as a wavelength separator, this Free Spectral Range has limited the wavelength band of this VIPA, because in general, this wavelength band is substantially equal to this Free Spectral Range.For example, if this thickness t is 50 microns, then the wavelength band of this VIPA is 16 nanometers, and the output angle of the wavelength band of each 16 nanometer in succession is repeated.
Therefore, the input beam of this VIPA can fall into a quite wide wavelength coverage.This wavelength coverage will be divided into many by the determined wavelength band of the Free Spectral Range of this VIPA.Concerning each wavelength band, be repeated from the output angle of this VIPA.
Usually be desirable to provide a kind of VIPA with broad wavelength band.For example, because up-to-date technical progress, the bandwidth of optical amplifier increases widely.People wish to obtain a VIPA with wide wavelength band or bandwidth, so that separate the light beam that is amplified by this optical amplifier effectively.In order to accomplish this point, the thickness t between all reflectings surface of this VIPA should be done more thinnerly.Yet thickness t can not be easily manufactured be come out less than 50 microns VIPA.
For the problem of the limited wavelength band that solves a VIPA, a VIPA can be used in combination with a wavelength separator (being also referred to as a demodulation multiplexer), so that a kind of device with a wide wavelength band is provided.
More particularly, Figure 16 (A) and Figure 16 (B) are two figure, illustrate according to one embodiment of present invention, a VIPA is followed the device that demodulation multiplexer is combined.Figure 16 (A) is the top view of this device, and Figure 16 (B) then is the side view of this device.
Referring now to Figure 16 (A) and Figure 16 (B),, an input beam, for example a wdm light beam advances to a collimation lens 210 from an optical fiber 200.Collimation lens 210 collimates these input beams, and this collimated light beam is sent to a semicylindrical lens 220.Semicylindrical lens 220 focuses on a VIPA230 with this light beam line.
VIPA produces an output beam (for example light beam), and it is sent to a demodulation multiplexer, and for example diffraction grating 240.Light or light beam that diffraction grating 240 is many separation with this light beam demultiplexing, they are focused on a focal plane 260 by a condenser lens 250.
In general, a VIPA, for example VIPA230 has than higher resolution in a narrow wavelength coverage.For example, Figure 17 (A) is a figure, and the relation of the output angle of a wavelength and a VIPA is described.Referring now to Figure 17 (A),, a VIPA has many wavelength bands 280 that repeat, and they are determined by the Free Spectral Range of this VIPA.In general, the bandwidth of each wavelength band 280 is substantially equal to this Free Spectral Range.
Shown in Figure 17 (A), all wavelength X 1, λ 2, and λ 3, and each among λ 4 and the λ 5 all is to disperse out with identical output angle θ from this VIPA.Therefore, this VIPA will disperse an output beam with output angle θ, and it has corresponding to all wavelength X 1, and λ 2, and λ 3, the wavelength components of λ 4 and λ 5.
Compare therewith, Figure 17 (B) is a figure, and the wavelength of a diffraction grating and output angle (relation) are described.Referring now to Figure 17 (B),, this diffraction grating has a wide wavelength band 290, and it comprises all wavelength X 1, and λ 2, and λ 3, λ 4 and λ 5.This diffraction grating will be respectively with all output angle θ 1, and θ 2, and θ 3, and θ 4 and θ 5 disperse all wavelength X 1, and λ 2, and λ 3, λ 4 and λ 5 (light beam).
From Figure 17 (A) and Figure 17 (B) as can be seen, a VIPA will allow to export some close relatively all wavelength with different significantly all output angles in a wavelength band (for example wavelength band 280).Therefore, a VIPA has than higher resolution in a narrow wavelength band.Compare therewith, a diffraction grating allows all wavelength in a wide wavelength band separated, but all output angles will be drawn close together.Therefore, a diffraction grating has lower resolution in a wide wavelength band.
By the resolution of reference VIPA230 and diffraction grating 240, Figure 16 (A) and Figure 16 (B) have been easy to understand now.More particularly, referring to Figure 16 (A) and Figure 16 (B), this input beam at first carries out demultiplexing with the VIPA230 of high-resolution once more, and the diffraction grating 240 with low resolution carries out further demultiplexing then.
Figure 18 is a figure, and an example of the work of this VIPA-diffraction instrument according to an embodiment of the invention is described.Referring now to Figure 18,, VIPA230 receives has all wavelength X 1, and λ 2, and λ 3, and λ 4, and λ 5, and λ 6, and λ 7, and λ 8, and λ 9, and λ 10, the input beam 295 of λ 11 and λ 12.In response, VIPA230 produces many light beams or output beam 300,310,320,330 and 340, and they blaze abroad from VIPA230.Output beam 310 comprises all wavelength X 2.λ 7 and λ 12.Output beam 320 comprises all wavelength X 3 and λ 8.Output beam 330 comprises all wavelength X 4 and λ 9.Output beam 340 comprises all wavelength X 5 and λ 10.
Diffraction grating 240 receives all output beams 300,310,320,330 and 340, and is the separating light beam that corresponds respectively to all wavelength of this output beam with each root output beam demultiplexing.For example, diffraction grating 240 with output beam 300 demultiplexings for having all wavelength X 1 respectively, 3 separating light beams of λ 6 and λ 11.
If dispersing the direction of dispersing of its all output beam, VIPA230 is not parallel to the direction of dispersing that diffraction grating is dispersed all separating light beams, then the combination of VIPA230 and diffraction grating 240 will allow a wdm light beam to have quite a large amount of all wavelength components close to each other, so that by demultiplexing accurately.
For example, Figure 18 illustrates a grid 350 with all points 1 to 12 that are arranged in grid map.All end points of all point 1 to 12 expression other all optical fiber.If VIPA230 disperses the direction of dispersing that direction is substantially perpendicular to diffraction grating 240, then the separating light beam that is produced by diffraction grating 240 optical fiber that can be arranged in the grid map is received.Adopt such configuration, wdm light beam with quite a large amount of all wavelength components close to each other can be by demultiplexing accurately.
Do not plan with VIPA230 disperse direction be defined in basically with diffraction grating 240 disperse direction perpendicular disperse direction.For example, this to disperse direction can be mutually " not parallel " simply.And the present invention does not plan to be subjected to all restrictions of dispersing the relation between the direction.Therefore, in some applications, disperse the direction all, keeping parallelism may be suitable.
Should be understood that a VIPA and diffraction grating the two according to one along an output angle output beam of dispersing direction.Therefore, for example, VIPA230 produces many output beams, and wherein each root all exhales with a different output angle from this VIPA.Yet all output beams are dispersed along the identical direction of dispersing.In Figure 18, the dispersing direction the two preferably all be linear basically of VIPA230 and diffraction grating 240.For example, in Figure 18, the direction of dispersing of VIPA230 can be vertical with respect to this figure, and the direction of dispersing of diffraction grating 240 can be level with respect to this figure.In this case, two to disperse direction will be mutually perpendicular.
Device among Figure 18 allow one be in input beam in the wide wavelength coverage with high precision and high resolving power by demultiplexing.For example, if VIPA230 is in the wavelength band of one 16 nanometer, with 20 wavelength of interval demultiplexing of 0.8 nanometer, and diffraction grating 240 5 wavelength of demultiplexing in each VIPA wavelength band, then can be within the total bandwidth of one 80 nanometer with 100 wavelength of interval demultiplexing of 0.08 nanometer.
In above-mentioned all embodiment of the present invention, diffraction grating 240 is used as a demodulation multiplexer.But the present invention does not plan to be confined to use a diffraction grating.As an alternative, can use any other suitable demodulation multiplexer.For example, can use the inteferometer coating of a multilayer.
According to above-mentioned all embodiment of the present invention, a device comprises a VIPA and a demodulation multiplexer, for example, and a diffraction grating.This VIPA receives the input beam with wavelength within a continuous wavelength scope.In response, this VIPA produces a corresponding output beam that blazes abroad from this VIPA.This output beam is essentially the linear direction of dispersing along one and disperses from this VIPA, and each wavelength all has a different output angle, and this output beam of dispersing comprises the wavelength components that many kinds are different.The light beam that this demodulation multiplexer is many separation with this output beam demultiplexing, they correspond respectively to the different wavelength components of many kinds in this output beam.The light beam of these many separation is essentially the linear direction of dispersing by this demodulation multiplexer along one and disperses, and the light beam that each root separates all has a different output angle.The direction of dispersing of this VIPA is not parallel to, and preferably perpendicular to the direction of dispersing of, this demodulation multiplexer.Lens can be provided, and it focuses on a focal plane with the light beam of these many separation, and the light beam that each root separates all is focused on this focal plane on the point different with other all separating light beams (focus).
Typically, this input beam is a wdm light beam, and it comprises the light beam more than two, and wherein each root all has a kind of different wavelength.Subsequently, this VIPA forms a relevant output beam at each the root light beam in this input beam.Each root output beam all is spatially differentiable concerning other all output beams, and each root output beam all comprises the wavelength components that many kinds are different.In this case, this demodulation multiplexer is the light beam of many separation with each root output beam demultiplexing, and they correspond respectively to the different wavelength components of many kinds in this output beam.Lens can be provided, and it focuses on a focal plane with all separating light beams from this demodulation multiplexer.The direction of dispersing that direction is substantially perpendicular to this demodulation multiplexer of dispersing as if this VIPA, then each root separating light beam can be focused on this focal plane on the point different with other all separating light beams (focus), makes different all grid maps that form on this focal plane.
According to shown in of the present invention all embodiment, for example, in Figure 18, a device comprises that to one the many input beams that respectively have different wave length carry out demultiplexing.This device comprises first and second demodulation multiplexers.For example, in Figure 18, VIPA230 is as first demodulation multiplexer, and diffraction grating 240 is then as second demodulation multiplexer.This first demodulation multiplexer is many output beams with this input beam demultiplexing, and they correspond respectively to many light beams in this input beam.This first demodulation multiplexer is essentially the linear all output beams of directional divergence of dispersing along one, and each root output beam all has a different output angle.And each root output beam all comprises many kinds of wavelength components.Second demodulation multiplexer is the light beam of many separation with each root output beam demultiplexing, and they correspond respectively to many kinds of wavelength components in this output beam.This second demodulation multiplexer is essentially the linear light beam of dispersing many separation of directional divergence along one, and the light beam that each root separates all has a different output angle.The direction of dispersing of second demodulation multiplexer is not parallel to, and preferably perpendicular to the direction of dispersing of, this first demodulation multiplexer.Do not plan this first and second demodulation multiplexer is confined to a VIPA and a diffraction grating.As an alternative, can use any suitable demodulation multiplexer, perhaps wavelength separator.
In general, a VIPA is angular divergence parts, and it has one and sees through the zone, be used for light beam is received this VIPA, and from this VIPA output beam.See through the zone by this, this VIPA receives the input beam with wavelength separately in a continuous wavelength scope.This VIPA causes that the repeatedly reflection of input beam is to produce self-interference and to form this output beam.This output beam is from this VIPA, and to follow the formed output beam of an input beam that has any other wavelength in this continuous wavelength scope spatially be differentiable.
Various lens are disclosed in this article.For example, Figure 16 (A) discloses collimation lens 210, the application of semicylindrical lens 220 and condenser lens 250.But the present invention does not plan to be confined to use the lens of any particular type.As an alternative, can use dissimilar lens or device so that suitable effect to be provided.
The noun of Shi Yonging " many " expression " more than one " in this article.Therefore, many light beams refer to " more than one " light beam.For example, two light beams are exactly many light beams.
Though shown and narrated several preferred embodiments of the present invention, but the professional person should understand, under the prerequisite that does not deviate from principle of the present invention and spirit, can make change to these embodiment, in these claims and equivalent thereof, will make stipulations to the scope of above-mentioned principle and spirit.

Claims (28)

1. a device comprises:
A virtual image phased array (VIPA) in order to receiving an input beam, and produces the output beam of a correspondence that blazes abroad from this VIPA, and this output beam comprises the wavelength components that many kinds are different; And
A demodulation multiplexer with the light beam that this output beam demultiplexing is many separation, corresponds respectively to the different wavelength components of many kinds in this output beam.
2. device according to claim 1, wherein:
This VIPA is essentially linear this output beam of directional divergence of dispersing along one,
This demodulation multiplexer is essentially the linear light beam of dispersing all separation of directional divergence along one,
This VIPA disperses the direction of dispersing that direction is not parallel to this demodulation multiplexer.
3. device according to claim 2, wherein this VIPA's disperses the disperse direction of direction perpendicular to this demodulation multiplexer.
4. one kind requires described device according to right 1, wherein:
This input beam is within the wavelength coverage, and the latter is divided into many by the determined wavelength band of the Free Spectral Range of this VIPA, and
In each wavelength band, this VIPA has the resolution that is higher than this demodulation multiplexer.
5. device according to claim 1, wherein:
This input beam has one and is in a wavelength within the continuous wavelength scope,
Along with this input beam changes its wavelength in this continuous wavelength scope, this VIPA is essentially linear this output beam of directional divergence of dispersing along one, and each wavelength all has a different output angle, and
This demodulation multiplexer is essentially the linear light beam of dispersing many separation of directional divergence along one, and the light beam that each root separates all has a different output angle, and this VIPA disperses the direction of dispersing that direction is not parallel to this demodulation multiplexer.
6. device according to claim 5, wherein this VIPA's disperses the direction of dispersing that direction is substantially perpendicular to this demodulation multiplexer.
7. device according to claim 1, wherein:
This VIPA has a Free Spectral Range,
The wavelength of this input beam is within the wavelength coverage, and the latter is divided into by determined many wavelength bands of the Free Spectral Range of this VIPA,
Concerning each wavelength band, along with this input beam changes its wavelength in this wavelength band, this VIPA is essentially linear this output beam of directional divergence of dispersing along one, and each wavelength all has a different output angle, and
This demodulation multiplexer is essentially the linear light beam of dispersing these many separation of directional divergence along one, and the light beam that each root separates all has a different output angle, and this VIPA disperses the direction of dispersing that direction is not parallel to this demodulation multiplexer.
8. device according to claim 1, wherein this demodulation multiplexer is a diffraction grating.
9. device according to claim 2, wherein this demodulation multiplexer is a diffraction grating.
10. device according to claim 1, wherein:
This VIPA is angular divergence parts, and it has one and sees through the zone, in order to light beam being received this VIPA, and from this VIPA output beam,
See through the zone by this, this VIPA is received in this input beam that has a wavelength separately in the continuous wavelength scope, and cause the repeatedly reflection of this input beam, to produce the self-interference that forms this output beam, this output beam is advanced from this VIPA, and it to follow the formed output beam of an input beam that has any other wavelength within this continuous wavelength scope spatially be differentiable.
11. a device according to claim 2 also comprises:
Lens, it focuses on the light beam of many separation on the focal plane, and the light beam that each root separates all is focused on this focal plane on the point different with other all separating light beams (focus).
12. a device according to claim 1, wherein:
This input beam comprises that two or many respectively have light beams of different wavelengths, and this VIPA forms an output beam separately at each the root light beam in this input beam, each root output beam spatially is differentiable with other all output beams, and each root output beam comprises the wavelength components that many kinds are different, and
This demodulation multiplexer is the light beam of many separation with each root output beam demultiplexing, and they correspond respectively to the different wavelength components of many kinds in this output beam.
13. a device according to claim 12 also comprises:
Lens, it will focus on the focal plane from the light beam of all separation of this demodulation multiplexer, the light beam that each root separates all is focused on this focal plane on the point different with other all separating light beams (focus), make different all on this focal plane grid map of formation.
14. a device comprises:
A virtual image phased array (VIPA), in order to receive an input beam that in a continuous wavelength scope, has a wavelength, and produce the output beam of a correspondence that blazes abroad from this VIPA, this output beam is from this VIPA, being essentially the linear direction of dispersing along one disperses, each wavelength all has a different output angle, and this output beam of dispersing comprises the wavelength components that many kinds are different; And
A demodulation multiplexer, with this output beam demultiplexing light beam that is many separation, they correspond respectively to the different wavelength components of many kinds in this output beam, the light beam of these many separation is essentially the linear directional divergence of dispersing by this demodulation multiplexer along one, the light beam that each root separates all has a different output angle, and this VIPA disperses the direction of dispersing that direction is not parallel to this demodulation multiplexer.
15. a device according to claim 14 also comprises:
Lens, it focuses on the light beam of many separation on the focal plane, and the light beam that each root separates all is focused on this focal plane on the point different with other all light beams that separate (focus).
16. a device according to claim 14, wherein:
This input beam comprises that two or many respectively have light beams of different wavelengths, and this VIPA is at each the root light beam in this input beam, form an output beam separately, each root output beam spatially is differentiable with other all output beams, and each root output beam comprises the wavelength components that many kinds are different, and
This demodulation multiplexer is the light beam of many separation with each root output beam demultiplexing, and they correspond respectively to the different wavelength components of many kinds in this output beam.
17. a device according to claim 16 also comprises:
Lens, it will focus on the focal plane from the light beam of all separation of this demodulation multiplexer, the light beam that each root separates all is focused on the focal plane on the point different with other all separating light beams (focus), make different all on this focal plane grid map of formation.
18. a device according to claim 14, wherein:
This VIPA is angular divergence parts, and it has one and sees through the zone, in order to light beam being received this VIPA, and from this VIPA output beam,
See through the zone by this, this VIPA is received in this input beam that has a wavelength separately in the continuous wavelength scope, and cause the repeatedly reflection of this input beam, to produce the self-interference that forms this output beam, this output beam is advanced from this VIPA, and to follow the formed output beam of an input beam that has any other wavelength in this continuous wavelength scope spatially be differentiable.
19. a device comprises:
Angular divergence parts, it has one and sees through the zone, in order to light beam being received this angular divergence parts, and from this angular divergence parts output beam,
See through the zone by this, these angular divergence parts receive an input beam that has a wavelength separately in a continuous wavelength scope, and cause the repeatedly reflection of this input beam, to produce the self-interference that forms this output beam, this output beam is advanced from these angular divergence parts, and to follow the formed output beam of an input beam that has any other wavelength in this continuous wavelength scope spatially be differentiable.This output beam is essentially the linear directional divergence of dispersing by these angular divergence parts along one, and each wavelength all has a different output angle, and this output beam of dispersing comprises the wavelength components that many kinds are different;
A demodulation multiplexer, with this output beam demultiplexing light beam that is many separation, they correspond respectively to the different wavelength components of many kinds in this output beam, the light beam of these many separation is essentially the linear directional divergence of dispersing by this demodulation multiplexer along one, the light beam that each root separates all has a different output angle, these angular divergence parts disperse the direction of dispersing that direction is not parallel to this demodulation multiplexer; And
Lens, it focuses on a focal plane with the light beam of many separation, and the light beam that each root separates all is focused on this focal plane on the point different with other all separating light beams (focus).
20. a device according to claim 19, wherein this demodulation multiplexer is a diffraction grating.
21. a device according to claim 19, wherein:
This input beam comprises that two or many respectively have light beams of different wavelengths, and these angular divergence parts form an output beam separately at each the root light beam in this input beam, each root output beam spatially is differentiable with other all output beams, and, each root output beam comprises the wavelength components that many kinds are different
This demodulation multiplexer is the light beam of many separation with each root output beam demultiplexing, and they correspond respectively to the different wavelength components of many kinds in this output beam; And
The light beam that these lens separate each root focuses on this focal plane on the point different with other all separating light beams (focus), make different all on this focal plane grid map of formation.
22. a device is used for comprising that the many input beams that respectively have light beams of different wavelengths carry out demultiplexing, this device comprises:
One first demodulation multiplexer, it is many output beams with this input beam demultiplexing, they correspond respectively to many light beams in this input beam, this first demodulation multiplexer is essentially linear these the many output beams of directional divergence of dispersing along one, each root output beam all has a different output angle, and each root output beam all comprises many kinds of wavelength components; And
One second demodulation multiplexer, it is with all light beam of each root output beam demultiplexing for separating, they correspond respectively to many kinds of wavelength components in this output beam, this second demodulation multiplexer is essentially the linear direction of dispersing with the light beam of these many separation along one and disperses, the light beam that each root separates all has a different output angle, this second demodulation multiplexer disperse the direction of dispersing that direction is not parallel to this first demodulation multiplexer.
23. a device according to claim 22, wherein this second demodulation multiplexer disperses the disperse direction of direction perpendicular to this first demodulation multiplexer.
24. a device according to claim 22, wherein this first demodulation multiplexer is a virtual image phased array (VIPA).
25. a device according to claim 22, wherein this second demodulation multiplexer is a diffraction grating.
26. a device according to claim 24, wherein this second demodulation multiplexer is a diffraction grating.
27. a device according to claim 22, wherein:
This first demodulation multiplexer has a corresponding Free Spectral Range;
This input beam is in the wavelength coverage, and the latter is divided into many by the determined wavelength band of the Free Spectral Range of this first demodulation multiplexer, and
In each wavelength band, this first demodulation multiplexer has the resolution that is higher than this second demodulation multiplexer.
28. a device according to claim 22 also comprises:
Lens, it will focus on the focal plane from all light beams of the separation of this second demodulation multiplexer, the light beam that each root separates all is focused on this focal plane on the point different with other all light beams that separate (focus), make different all on this focal plane grid map of formation.
CNB981194605A 1997-10-10 1998-10-07 Apparatus which includes virtually imaged phased array (VIPA) in combination with wavelength splitter to demultiplex wavelength division multiplexed (WDM) light Expired - Fee Related CN1154865C (en)

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US08/948,945 US5973838A (en) 1995-07-26 1997-10-10 Apparatus which includes a virtually imaged phased array (VIPA) in combination with a wavelength splitter to demultiplex wavelength division multiplexed (WDM) light
US948945/97 1997-10-10

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6608721B1 (en) 2000-06-02 2003-08-19 Essex Corporation Optical tapped delay line
US6392807B1 (en) * 2000-12-22 2002-05-21 Avanex Corporation Tunable chromatic dispersion compensator utilizing a virtually imaged phased array and folded light paths
JP3973021B2 (en) 2002-03-29 2007-09-05 富士通株式会社 Equipment using a virtual imaged phased array (VIPA) with improved transmission wavelength characteristics of output light
JP2004037840A (en) 2002-07-03 2004-02-05 Olympus Corp Dispersion compensator and dispersion compensation system
US7720226B2 (en) 2002-11-19 2010-05-18 Essex Corporation Private and secure optical communication system using an optical tapped delay line
JP4810083B2 (en) 2004-11-10 2011-11-09 富士通株式会社 Dispersion compensation device and optical transmission system
KR100765432B1 (en) * 2006-02-23 2007-10-11 경북대학교 산학협력단 Micro optic interferometric filter
JP2015212798A (en) * 2014-04-15 2015-11-26 日本電信電話株式会社 Wavelength dispersion element
JP6225075B2 (en) * 2014-06-11 2017-11-01 日本電信電話株式会社 Wavelength selective switch
JP6212456B2 (en) * 2014-09-08 2017-10-11 日本電信電話株式会社 Wavelength selective switch

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0566001B1 (en) * 1992-04-07 1999-07-14 Raytheon Company Wide spectral bandwidth virtual image display optical system
JP3464081B2 (en) * 1995-07-26 2003-11-05 富士通株式会社 Wavelength splitter

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107346085A (en) * 2016-04-08 2017-11-14 韩国科学技术院 Light radiator for adjusting radiation angle of light wave radiation to free space

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