EP1514334A2 - Dispositif de transmission de signaux optiques, procede de transmission de signaux optiques et modulateur optique - Google Patents
Dispositif de transmission de signaux optiques, procede de transmission de signaux optiques et modulateur optiqueInfo
- Publication number
- EP1514334A2 EP1514334A2 EP03740100A EP03740100A EP1514334A2 EP 1514334 A2 EP1514334 A2 EP 1514334A2 EP 03740100 A EP03740100 A EP 03740100A EP 03740100 A EP03740100 A EP 03740100A EP 1514334 A2 EP1514334 A2 EP 1514334A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- semiconductor element
- energy level
- emitted
- light
- emission direction
- 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- Withdrawn
Links
- 230000003287 optical effect Effects 0.000 title claims abstract description 48
- 230000008054 signal transmission Effects 0.000 title claims abstract description 24
- 238000000034 method Methods 0.000 title claims description 11
- 239000004065 semiconductor Substances 0.000 claims abstract description 150
- 230000005684 electric field Effects 0.000 claims abstract description 32
- 238000010521 absorption reaction Methods 0.000 claims abstract description 21
- 230000001427 coherent effect Effects 0.000 claims description 53
- 239000002096 quantum dot Substances 0.000 claims description 39
- JBRZTFJDHDCESZ-UHFFFAOYSA-N AsGa Chemical compound [As]#[Ga] JBRZTFJDHDCESZ-UHFFFAOYSA-N 0.000 claims description 16
- FTWRSWRBSVXQPI-UHFFFAOYSA-N alumanylidynearsane;gallanylidynearsane Chemical compound [As]#[Al].[As]#[Ga] FTWRSWRBSVXQPI-UHFFFAOYSA-N 0.000 claims description 16
- 229910001218 Gallium arsenide Inorganic materials 0.000 claims description 13
- 229910000530 Gallium indium arsenide Inorganic materials 0.000 claims description 13
- KXNLCSXBJCPWGL-UHFFFAOYSA-N [Ga].[As].[In] Chemical group [Ga].[As].[In] KXNLCSXBJCPWGL-UHFFFAOYSA-N 0.000 claims description 8
- 239000002800 charge carrier Substances 0.000 claims description 8
- 230000008878 coupling Effects 0.000 claims description 8
- 238000010168 coupling process Methods 0.000 claims description 8
- 238000005859 coupling reaction Methods 0.000 claims description 8
- RPQDHPTXJYYUPQ-UHFFFAOYSA-N indium arsenide Chemical compound [In]#[As] RPQDHPTXJYYUPQ-UHFFFAOYSA-N 0.000 claims description 7
- 229910000673 Indium arsenide Inorganic materials 0.000 claims description 6
- 230000007704 transition Effects 0.000 claims description 5
- 230000002745 absorbent Effects 0.000 claims description 4
- 239000002250 absorbent Substances 0.000 claims description 4
- 239000013078 crystal Substances 0.000 claims description 4
- 230000005540 biological transmission Effects 0.000 description 17
- 238000010586 diagram Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 230000005855 radiation Effects 0.000 description 5
- 239000000463 material Substances 0.000 description 4
- 230000004888 barrier function Effects 0.000 description 3
- BJQHLKABXJIVAM-UHFFFAOYSA-N bis(2-ethylhexyl) phthalate Chemical group CCCCC(CC)COC(=O)C1=CC=CC=C1C(=O)OCC(CC)CCCC BJQHLKABXJIVAM-UHFFFAOYSA-N 0.000 description 3
- 239000003365 glass fiber Substances 0.000 description 3
- 230000000737 periodic effect Effects 0.000 description 3
- 238000000926 separation method Methods 0.000 description 3
- 238000001228 spectrum Methods 0.000 description 3
- 230000001154 acute effect Effects 0.000 description 2
- 230000003321 amplification Effects 0.000 description 2
- 125000004429 atom Chemical group 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 238000005562 fading Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- 238000003199 nucleic acid amplification method Methods 0.000 description 2
- 239000004038 photonic crystal Substances 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000005701 quantum confined stark effect Effects 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- MDPILPRLPQYEEN-UHFFFAOYSA-N aluminium arsenide Chemical compound [As]#[Al] MDPILPRLPQYEEN-UHFFFAOYSA-N 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000004134 energy conservation Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000005281 excited state Effects 0.000 description 1
- 230000005283 ground state Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 230000003071 parasitic effect Effects 0.000 description 1
- 230000006798 recombination Effects 0.000 description 1
- 238000005215 recombination Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 230000002269 spontaneous effect Effects 0.000 description 1
- 230000005533 two-dimensional electron gas Effects 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y20/00—Nanooptics, e.g. quantum optics or photonic crystals
-
- 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
- H01S5/026—Monolithically integrated components, e.g. waveguides, monitoring photo-detectors, drivers
- H01S5/0265—Intensity modulators
-
- 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
- H01S5/04—Processes or apparatus for excitation, e.g. pumping, e.g. by electron beams
- H01S5/041—Optical 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
- H01S5/00—Semiconductor lasers
- H01S5/10—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region
- H01S5/18—Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities
- H01S5/183—Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities having only vertical cavities, e.g. vertical cavity surface-emitting lasers [VCSEL]
-
- 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
- H01S5/30—Structure or shape of the active region; Materials used for the active region
- H01S5/34—Structure or shape of the active region; Materials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers
- H01S5/341—Structures having reduced dimensionality, e.g. quantum wires
- H01S5/3412—Structures having reduced dimensionality, e.g. quantum wires quantum box or quantum dash
-
- 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
- H01S5/4025—Array arrangements, e.g. constituted by discrete laser diodes or laser bar
- H01S5/4031—Edge-emitting structures
- H01S5/4056—Edge-emitting structures emitting light in more than one direction
Definitions
- the invention relates to a device for optical signal transmission, a method for optical signal transmission and an optical modulator.
- a known device for optical signal transmission is based on modulation of the coherent light emitted by a laser element with a data signal.
- the emitted coherent light can be directly modulated by changing the electrical pump current accordingly. However, this can only be done
- an external modulator in the beam path of a laser element, which modulates the loss of the coherent laser light emitted by the laser element by applying an electric field with a frequency corresponding to the desired data transmission rate between a transparent and an absorbing state is switched.
- the modulator is usually designed as a “quantum well” semiconductor structure which has a step-like density of states with discrete energy states in the valence or conduction band.
- Semiconductor structure is formed so that its absorption edge, i.e. the lowest transition energy for charge carriers in the energy spectrum of the semiconductor structure, in the field-free state, is slightly above the energy of the coherent light to be modulated and emitted by the laser element.
- the so-called “quantum confined stark effect” is used, according to which the quantized energy states of the valence and conduction band in a "quantum well” semiconductor structure are influenced by applying an external electric field perpendicular to the interface of the quantum well.
- an electric field leads to an energetic increase in the hole states and an energetic decrease in the electron states in the energy spectrum of the semiconductor structure, so that the
- Absorption edge of the semiconductor structure is shifted to lower energies.
- the amplitude of the electric field applied to the "quantum well” semiconductor laser is selected such that the absorption edge caused by the electric field is sufficient to reduce the "quantum well” Switch semiconductor structure from the transparent state to the absorbent state.
- This known device for optical data transmission thus has the disadvantage that it is only suitable for relatively low light outputs, which are not sufficient for direct data transmission.
- a quantum cascade laser is described in [1], the laser being controlled by means of an optical control method.
- the 5 light beams used for optical control of the laser have a wavelength that is significantly less than the wavelength of the unipolar laser. This means that the light beams can be modulated much faster than the laser light itself.
- [3] describes a method for modulating an optical beam and an optical modulator Quantum dots, the modulator containing an etalon structure with an absorption edge close to the wavelength of the optical bundle to be modulated and material with a narrower band gap, which is placed between layers of material with a larger band gap. Means are also provided for directing a polarized optical control bundle onto the etalon structure with the electric field of the polarized optical control bundle perpendicular to a direction of the quantum dots for modulating the absorption edge of the etalon structure.
- [4] describes an optical modulator with quantum dots, in which the optical wavelength lies outside the energy level range defined by the two energy levels of the semiconductor laser element.
- [5] describes a quantum dot element in which no light is generated.
- [6] discloses a method for manufacturing a plurality of different semiconductor elements with highly induced areas.
- [7] describes a laser with quantum dot structures.
- the invention is therefore based on the problem of creating a device for optical signal transmission, a method for optical signal transmission and an optical modulator which are suitable for remote data transmission using high data transmission rates and high light outputs.
- the problem is solved by the optical device
- a device for optical signal transmission has a laser element, by means of which, preferably, coherent light can be emitted in a first emission direction, and a semiconductor element arranged in the first emission direction.
- the laser element can be any laser, for example a gallium arsenide semiconductor laser or a semiconductor laser with an indium-gallium-arsenide / gallium-arsenide / aluminum-gallium-arsenide heterostructure (InGaAs / GaAs / AlGaAs hetero structure) or with an indium - Arsenide / indium-gallium-arsenide / aluminum-gallium-arsenide heterostructure (InAs / lnGaAs / AlGaAs heterostructure).
- a gallium arsenide semiconductor laser or a semiconductor laser with an indium-gallium-arsenide / gallium-arsenide / aluminum-gallium-arsenide heterostructure InGaAs / GaAs / AlGaAs heterostructure
- InAs / lnGaAs / AlGaAs heterostructure InAs / lnGaAs / AlG
- Means are also provided for applying an electric field to the semiconductor element, as a result of which the semiconductor element can be switched between a transparent and an absorbing state with respect to the preferably coherent light emitted by the laser element.
- the semiconductor element has at least a third energy level between a first energy level and a second energy level lying above the first energy level, wherein in the absorbing state of the semiconductor element, light can be emitted by the semiconductor element in a second emission direction by absorption of the coherent light emitted by the laser element.
- a population inversion between the third energy level and the first is preferably achieved by absorption of the coherent light emitted by the laser element
- Energy scheme of the semiconductor element may also be a fourth energy level and further quantized energy levels.
- the third energy level is designed as a metastable energy level.
- a particularly effective absorption mechanism is provided in the device according to the invention, in which "fading" of the semiconductor element acting as a loss modulator is effectively prevented.
- the light emitted from the semiconductor element becomes
- the device is preferably emitted in a second emission direction different from the first emission direction, in which case there is no interaction with the coherent light emitted by the laser element, which interferes with the optical signal transmission.
- .0 embodiment of the invention is very simple and therefore inexpensive to manufacture and ensures a safe and therefore robust separation of the light emitted in the first emission direction from the light emitted in the second emission direction.
- the first emission direction is the same as the second emission direction. In this case, due to their different wavelengths, for example by means of a
- Heating of the semiconductor element leads.
- the absorption process is based on a purely optical effect, that is to say the operating frequency of the semiconductor element acting as a loss modulator and thus the achievable data transmission rate is not limited by parasitic electrical effects.
- the electric field applied to the semiconductor element is only used to shift the absorption edge of the semiconductor element. Since the semiconductor element is used as a purely optical element, in particular it does not have to consist of an electrically conductive material.
- the device according to the invention is fundamentally faster than the devices according to the prior art, since it is clearly no longer necessary to electrically vacuum charge carriers.
- the semiconductor element for forming the metastable third energy level has at least one semiconductor layer with quantum dots formed therein.
- quantum dots are understood to mean zero-dimensional electron systems which, owing to a restriction of the electron movement in all three spatial directions, have discrete energy spectra which are SO comparable to those of natural atoms, so that the quantum dots can be regarded as artificial atoms.
- the semiconductor layer can be produced from any semiconductor material in which such quantum dots are formed.
- the semiconductor layer can have an indium-gallium-arsenide / gallium-arsenide / aluminum-gallium-arsenide heterostructure or an indium-arsenide / indium-gallium-arsenide / Gal1ium-arsenide / aluminum-gallium-arsenide heterostructure, so that forms a two-dimensional electron gas with quantum dots therein in a known manner at the boundary layer of the heterostructure.
- the semiconductor layer with quantum dots formed therein can itself be a quantum well layer embedded between barrier layers.
- quantum dots made of InAs can be embedded in an InGaAs quantum well between GaAs barriers.
- In GaAs quantum dots AlGaAs is suitable as a quantum well material between AlAs barriers.
- the third (upper) energy level can be a bound energy state of the quantum well in the surrounding
- a plurality or a plurality of quantum well layers are arranged one above the other, a layer preferably made of GaAs or AlGaAs being provided between each two quantum well layers.
- a stack structure with several quantum well layers is thus clearly formed.
- Stacks of layers with quantum dots are provided, preferably integrated into a plurality of quantum well layers.
- a plurality of layers with quantum dots can also be provided in only one quantum well layer, or a plurality of layers of quantum dots can be embedded directly in the matrix.
- the semiconductor element is preferably designed such that in the .0 transparent state the energy of the light, preferably coherent, emitted by the laser element is greater than that
- the semiconductor element is also preferably designed such that: 0 the transition time of charge carriers from the second
- (Upper) energy level in the third energy level is significantly smaller than the period of the electrical field applied to the semiconductor element. In this way, the achievable frequency of the loss modulation and thus the achievable data transmission rate are not restricted by the relaxation of charge carriers from the second (upper) energy level to the third energy level.
- the first and second emission directions 0 are preferably perpendicular to one another, so that the coherent light emitted by the semiconductor element can be coupled out in a simple manner.
- the two emission directions can be any acute or obtuse angle between 0 ° and Take 359 ° to each other, preferably an acute angle, for example of 30 ° or 60 °.
- These means for repeatedly coupling the light, preferably coherent, emitted by the laser element into the semiconductor element can include at least one selective Bragg reflector, at least one metallic mirror, at least one photonic crystal or at least one broken crystal with a refractive index jump to the adjacent medium (e.g. air ) exhibit.
- the laser element and the semiconductor element are arranged in a common optical resonator.
- loss modulation by the semiconductor element already takes place in the resonator, which effects the amplification of the induced emission by the laser element, so that the light emerging from the resonator and emitted by the laser element is already modulated with a frequency corresponding to the desired data transmission rate and for further optical signal transmission, for example, can be coupled directly into a glass fiber cable.
- An optical modulator for loss modulating the, preferably coherent, light emitted by a laser element has a semiconductor element and means for applying an electric field to the semiconductor element, as a result of which the semiconductor element is between a transparent and an absorbing state with respect to the, preferably coherent, light emitted by the laser element is switchable to.
- the semiconductor element has at least one, preferably metastable, third energy level between a first energy level and a second energy level lying above the first energy level.
- a population inversion between the third energy level and the first energy level can be generated by absorption of the coherent light emitted by the laser element, and coherent light can be emitted by the semiconductor element in a second emission direction different from the first emission direction.
- a coherent light is emitted in a first emission direction by means of a laser element; an electrical field is applied to a semiconductor element arranged in the first emission direction, which has at least one, preferably metastable, third energy level between a first energy level and a second energy level above the first energy level, whereby the semiconductor element between a transparent and a absorbent state with respect to that of the
- Laser element emitted coherent light is switched; wherein in the absorbing state of the semiconductor element, by absorption of the light, preferably coherent, emitted by the laser element, preferably a population inversion between the metastable third energy level and the first energy level is generated, and preferably coherent light in a second direction different from the first emission direction
- Emission direction is emitted by the semiconductor element.
- FIG. 2 (a) - (b) the energy diagram of a semiconductor element used in the device according to the invention with (FIG. 2 (a)) and without (FIG. 2 (b)) an applied electric field;
- FIG. 3 (a) is a diagram illustrating the electronic density of states as a function of the energy for a semiconductor element. which is a layer with formed therein
- FIG. 3 (b) is a diagram illustrating the electronic density of states as a function of the energy for a semiconductor element which has a quantum well layer with quantum dots formed therein;
- the semiconductor element 100 has a semiconductor layer 101 with quantum dots 102 formed therein and, in the exemplary embodiment shown, is made of an indium-gallium-arsenide / aluminum-gallium-arsenide heterostructure (InGaAs / AlGaAs-heterostructure) or of a gallium-arsenide / aluminum Gallium arsenide heterostructure (GaAs / AIGaAs heterostructure) constructed.
- InGaAs / AlGaAs-heterostructure indium-gallium-arsenide / aluminum-gallium-arsenide heterostructure
- GaAs / AIGaAs heterostructure gallium-arsenide / aluminum Gallium arsenide heterostructure
- Each of the Bragg reflectors 103 represents a spatially periodic laser structure, that is to say a region with a spatially periodic refractive index, according to this
- Embodiment a spatially periodic laser structure made of gallium arsenide / aluminum arsenide.
- AlGaAs Aluminum gallium arsenide
- the semiconductor layer systems 203, 204 are in the illustrated embodiment aluminum-gallium arsenide constructed, wherein the semiconductor layer systems 203, 204 one or more semiconductor layers 201 made of gallium arsenide limit, • which semiconductor layers form 201 quantum wells.
- selective Bragg reflectors 205 are provided on opposite sides of the semiconductor layer 201.
- a laser element is provided (not shown), which emits coherent light 104 in an emission direction shown by the horizontal dashed arrow in FIG.la, b, so that this coherent light strikes the semiconductor element 100 or 200.
- the semiconductor structure formed in the semiconductor element 100 or 200 has an energy scheme in which there is at least one metastable third energy level between a first energy level and a second energy level lying above the first energy level, as will be explained in more detail below.
- an electric field is applied with a frequency corresponding to the desired data transmission rate the semiconductor element 100 and 200 applied.
- the mode of operation of the device in the presence of an electrical field is explained in more detail below with reference to the energy schemes shown in FIGS. 2a and 2b.
- FIG. 2 shows examples of energy schemes 300, 400 for a semiconductor layer with four discrete energy levels, the state without an applied electric field being shown in FIG. 2a and the state with an applied electric field being shown in FIG. 2a.
- the energy scheme 300 has two discrete energy levels 301 and 302 in the valence band E v and two further discrete energy levels 303 and 304 in the conduction band E ⁇ _.
- the energy level 303 here corresponds to the above-mentioned metastable, third energy level, while the energy levels 301 and 304 correspond to the above-mentioned first and second energy levels.
- the energy of the incident 5 coherent light 305 does not correspond to a transition in the region which is permitted on the basis of the quantum mechanical selection rules
- Semiconductor element for the coherent light 305 is transparent. .0
- 5b shows a corresponding energy diagram 400 in an external electrical field, again the energy level 403 corresponding to the above-mentioned metastable, third energy level, while the energy levels 401 and 404 correspond to the above-mentioned first and second
- the individual energy levels 301-304 in FIG. 2a or 401-404 in FIG. 2b can be excited states of the quantum dots formed in the semiconductor element used, so that the
- the density of states is not exactly delta-shaped, but has a finite, yet very narrow spread.
- State density follows a delta function 601, while the state density belonging to the surrounding quantum wells is step-like (according to FIG. 3b) (with steps 602, 603, ).
- This embodiment of the invention has the particular advantage that the wavelength of the laser light does not have to exactly match the respective energy level so that the laser light is absorbed.
- the discrete energy levels 401, 402 of the valence band E v and the discrete energy levels 403, 404 of the conduction band E in the energy diagram 400 are as above that the
- Energy of the incident coherent light 405 is just equal to the energy difference between the lower energy level 401 of the valence band E v and the upper energy level 404 of the conduction band E L. As a result, photons of the incident coherent light 405 are absorbed, as shown by the solid arrow 406 in Fig. 2b.
- a relaxation of the charge carriers excited by the coherent light 105 into the energy level 404 into the energy level 403 takes place relatively quickly, for example in the order of magnitude of picoseconds, whereas the subsequent relaxation of the charge carriers from the energy level 403 into the ground state 401 or in the energy level 402 of the valence band E v takes place relatively slowly, for example in the order of milliseconds, since the energy level 303 or 403 is metastable.
- the size of the applied electric field is chosen so that when the electric field is applied, the energy difference between the discrete, metastable energy level of the quantum dots and the energy level of the quantum dots above (in
- Fig.lb just corresponds to the energy of the coherent light emitted by the laser element to be modulated, so that a switch between the transparent and the absorbing state of the semiconductor element 100 or 200 and thus a
- the Bragg reflectors 103 and 205 are each designed to reflect 10 light which has an energy corresponding to this energy difference between the metastable third energy level and the first energy level with an applied electrical field, so that by repeated Reflection of the coherent light emitted by the semiconductor element, the induced emission of the semiconductor element 100 or 200 is amplified.
- the semiconductor element 100 or 200 emits light which is coherent in a second emission direction perpendicular to the first emission direction, which is represented by an arrow 105 and 206 in Fig.la and Fig.lb.
- This coherent light can be coupled out in a simple manner or else used in another way.
- the semiconductor element 100 or 200 is arranged relative to the laser element such that the
- Semiconductor element 100 outgoing emission of coherent light takes place in an emission direction different from the first emission direction of the laser element.
- the two emission directions of laser element and semiconductor element 100 and 200 are perpendicular to each other.
- the light emitted by the (not shown) laser element and modulated by the semiconductor element can be coupled into a glass fiber cable for further optical signal transmission to the destination.
- the field-free and thus transparent state of the semiconductor element 100 or 200 corresponds to the transmission of a logical "1"
- the absorbing state of the semiconductor element 100 or 200 corresponds to the writing of a logical "0".
- Fig.la and Fig.lb can also be modified so that additional Reflectors in the form of Bragg reflectors, metallic mirrors, photonic crystals or broken crystal edges along the first emission direction of the coherent light 105 are provided on both sides of the semiconductor element 100 or 200, in order to couple the coherent light 105 into the semiconductor element 100 or 200 by multiple coupling to increase the absorption occurring when an electric field is applied.
- the semiconductor element 100 or 200 and the laser element can also be arranged in a common resonator.
- the loss modulation by the semiconductor element already takes place in the resonator, which effects the amplification of the induced emission by the laser element, so that the coherent light emerging from the resonator and emitted by the laser element is already modulated at a frequency corresponding to the desired data transmission rate and can be coupled directly into a glass fiber cable for further optical signal transmission, for example.
- An optical modulator as a semiconductor element has a layer made of aluminum gallium arsenide, on which a layer stack of several quantum well layers made of indium gallium arsenide and intermediate layers made of aluminum gallium arsenide is applied, in each case alternately a quantum well layer and an intermediate layer applied thereon are provided.
- Each quantum well layer has one or a plurality of quantum dot layers with quantum dots made of indium arsenide.
- coherent laser light to be modulated is radiated into the optical modulator, in particular in the area of the quantum well layers, modulated there in the desired manner and output as modulated laser light, likewise in the first emission direction.
- the laser light generated by the quantum dots in the manner explained above in the context of the first and the second exemplary embodiment is emitted in a second emission direction, according to an alternative embodiment in a third emission direction.
- the second emission direction and the third emission direction are perpendicular to the first emission direction. Furthermore, the second emission direction and the third emission direction are perpendicular to one another.
- the electric field is applied in the second emission direction.
Landscapes
- Physics & Mathematics (AREA)
- Nanotechnology (AREA)
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Optics & Photonics (AREA)
- Biophysics (AREA)
- Life Sciences & Earth Sciences (AREA)
- Electromagnetism (AREA)
- General Physics & Mathematics (AREA)
- Crystallography & Structural Chemistry (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Semiconductor Lasers (AREA)
- Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)
- Optical Communication System (AREA)
Abstract
Dispositif de transmission de signaux optiques qui possède un élément laser, un élément à semi-conducteur placé dans la direction d'émission de l'élément laser et possédant un troisième niveau d'énergie situé entre des premier et deuxième niveaux d'énergie, et des moyens permettant d'appliquer un champ électrique. Lorsqu'un champ électrique est appliqué, de la lumière peut être émise dans une seconde direction d'émission par absorption de la lumière émise par l'élément laser.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2002127168 DE10227168A1 (de) | 2002-06-18 | 2002-06-18 | Vorrichtung zur optischen Signalübertragung, Verfahren zur optischen Signalübertragung und optischer Modulator |
| DE10227168 | 2002-06-18 | ||
| PCT/DE2003/002044 WO2003107493A2 (fr) | 2002-06-18 | 2003-06-18 | Dispositif de transmission de signaux optiques, procede de transmission de signaux optiques et modulateur optique |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| EP1514334A2 true EP1514334A2 (fr) | 2005-03-16 |
Family
ID=29723232
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP03740100A Withdrawn EP1514334A2 (fr) | 2002-06-18 | 2003-06-18 | Dispositif de transmission de signaux optiques, procede de transmission de signaux optiques et modulateur optique |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP1514334A2 (fr) |
| DE (1) | DE10227168A1 (fr) |
| WO (1) | WO2003107493A2 (fr) |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2215072A (en) * | 1988-02-12 | 1989-09-13 | Philips Electronic Associated | A method of modulating an optical beam |
| US5175739A (en) * | 1988-09-09 | 1992-12-29 | Fujitsu Limited | Semiconductor optical device having a non-linear operational characteristic |
| EP0535293A1 (fr) * | 1991-01-29 | 1993-04-07 | Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V. | Procédé de fabrication d'un dispositif semiconducteur compositionnel |
| US5300789A (en) * | 1991-12-24 | 1994-04-05 | At&T Bell Laboratories | Article comprising means for modulating the optical transparency of a semiconductor body, and method of operating the article |
| JP2536714B2 (ja) * | 1993-03-03 | 1996-09-18 | 日本電気株式会社 | 光変調器集積型多重量子井戸構造半導体レ―ザ素子 |
| JP3572673B2 (ja) * | 1994-08-31 | 2004-10-06 | ソニー株式会社 | 量子素子 |
| FR2751480A1 (fr) * | 1996-07-19 | 1998-01-23 | Commissariat Energie Atomique | Microlaser solide a declenchement actif par semi-conducteur |
| JPH1084164A (ja) * | 1996-09-06 | 1998-03-31 | Fujitsu Ltd | 半導体量子ドット光変調装置 |
| FR2784514B1 (fr) * | 1998-10-13 | 2001-04-27 | Thomson Csf | Procede de controle d'un laser semiconducteur unipolaire |
-
2002
- 2002-06-18 DE DE2002127168 patent/DE10227168A1/de not_active Ceased
-
2003
- 2003-06-18 WO PCT/DE2003/002044 patent/WO2003107493A2/fr not_active Ceased
- 2003-06-18 EP EP03740100A patent/EP1514334A2/fr not_active Withdrawn
Non-Patent Citations (1)
| Title |
|---|
| See references of WO03107493A3 * |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2003107493A3 (fr) | 2004-07-29 |
| WO2003107493A2 (fr) | 2003-12-24 |
| DE10227168A1 (de) | 2004-01-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| DE69217344T2 (de) | Abstimmbarer Laser mit gekoppelter Quantumwell-Struktur | |
| EP0409177B1 (fr) | Amplificateur optique à contre-réaction | |
| DE69404760T2 (de) | Monolithisch integrierte Laser-Modulator-Anordnung mit Multiquantumwell-Struktur | |
| DE69328234T2 (de) | Einzeln adressierbare Halbleiterlaserdioden mit integrierten verlustarmen passiven Wellenleitern | |
| DE69610598T2 (de) | Langwelliger,oberflächenemittierender laser mit vertikalem resonator und integrierter,vertikaler optischer pumpquelle | |
| DE69033405T2 (de) | Abstimmbare Laserdiode mit verteilter Rückkoppelung | |
| DE69719439T2 (de) | Mehrschichtspiegel mit Stickstoff enthaltenden Verbindungshalbleitern und oberflächenemittierende Lichtquelle unter Verwendung desselben | |
| DE69409539T2 (de) | Optische schalteinrichtung | |
| DE3751548T2 (de) | Halbleiterlaser. | |
| EP2223397B1 (fr) | Source de lumière laser et procédé de fabrication d'une source de lumière laser | |
| DE69606812T2 (de) | Halbleiterlaser | |
| DE69308070T2 (de) | Verfahren und Vorrichtung zur Modulation und Verstärkung von Lichtstrahlen | |
| EP1399994B1 (fr) | Emetteur de photons et dispositif de transmission de donnees | |
| DE69028734T2 (de) | Optische Halbleitervorrichtung | |
| DE69606596T2 (de) | Halbleitende Emissionsvorrichtung mit schneller Wellenlängenmodulation | |
| DE69203998T2 (de) | Monolithisch integrierte Laserdioden-Modulator mit einem stark gekoppelten Übergitter. | |
| DE3586934T2 (de) | Halbleiterlaser. | |
| DE10229211A1 (de) | Polarisationsgesteuerter oberflächenemittierender Laser mit vertikalem Hohlraum unter Verwendung einer asymmetrischen strombegrenzenden Öffnung | |
| DE10147353A1 (de) | Halbleiterlaser | |
| DE60204168T2 (de) | Phasenverschobene oberflächenemittierende dfb laserstrukturen mit verstärkenden oder absorbierenden gittern | |
| DE69400656T2 (de) | Integrierte Lichtquelle mit Multiquantumwell-Diodenlaser/Modulator | |
| DE69033773T2 (de) | Anordnung zur optischen Verbindung | |
| DE69123902T2 (de) | Lichtemittierende Vorrichtung unter Ausnutzung der Quantenelektrodynamik im Hohlraum | |
| DE69506284T2 (de) | Gütegeschaltetes Lasersystem | |
| WO2008086789A2 (fr) | Laser unipolaire à cascade quantique de haute efficacité |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
| 17P | Request for examination filed |
Effective date: 20041216 |
|
| AK | Designated contracting states |
Kind code of ref document: A2 Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PT RO SE SI SK TR |
|
| STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN |
|
| 18W | Application withdrawn |
Effective date: 20050805 |