WO2001063708A2 - Appareil a cavite verticale a jonction a effet tunnel - Google Patents

Appareil a cavite verticale a jonction a effet tunnel Download PDF

Info

Publication number
WO2001063708A2
WO2001063708A2 PCT/US2001/006163 US0106163W WO0163708A2 WO 2001063708 A2 WO2001063708 A2 WO 2001063708A2 US 0106163 W US0106163 W US 0106163W WO 0163708 A2 WO0163708 A2 WO 0163708A2
Authority
WO
WIPO (PCT)
Prior art keywords
quantum wells
mirror
tunnel junction
active region
mirrors
Prior art date
Application number
PCT/US2001/006163
Other languages
English (en)
Other versions
WO2001063708A3 (fr
Inventor
Julien Boucart
Constance Chang-Hasnain
Mitch Jansen
Rashit Nabiev
Wupen Yuen
Original Assignee
Bandwidth9, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US09/603,140 external-priority patent/US6487230B1/en
Priority claimed from US09/602,444 external-priority patent/US6493371B1/en
Priority claimed from US09/603,227 external-priority patent/US6760357B1/en
Priority claimed from US09/603,239 external-priority patent/US6487231B1/en
Priority claimed from US09/603,242 external-priority patent/US6493373B1/en
Priority claimed from US09/602,817 external-priority patent/US6490311B1/en
Priority claimed from US09/602,454 external-priority patent/US6493372B1/en
Priority claimed from US09/603,296 external-priority patent/US6535541B1/en
Application filed by Bandwidth9, Inc. filed Critical Bandwidth9, Inc.
Priority to AU2001239892A priority Critical patent/AU2001239892A1/en
Publication of WO2001063708A2 publication Critical patent/WO2001063708A2/fr
Publication of WO2001063708A3 publication Critical patent/WO2001063708A3/fr

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/40—Arrangement of two or more semiconductor lasers, not provided for in groups H01S5/02 - H01S5/30
    • H01S5/42—Arrays of surface emitting lasers
    • H01S5/423—Arrays of surface emitting lasers having a vertical cavity
    • H01S5/426—Vertically stacked cavities
    • 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]
    • H01S5/18308—Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities having only vertical cavities, e.g. vertical cavity surface-emitting lasers [VCSEL] having a special structure for lateral current or light confinement
    • H01S5/18311—Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities having only vertical cavities, e.g. vertical cavity surface-emitting lasers [VCSEL] having a special structure for lateral current or light confinement using selective oxidation
    • 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]
    • H01S5/18308—Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities having only vertical cavities, e.g. vertical cavity surface-emitting lasers [VCSEL] having a special structure for lateral current or light confinement
    • H01S5/18322—Position of the structure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • 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]
    • H01S5/18341—Intra-cavity contacts
    • 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]
    • H01S5/18361—Structure of the reflectors, e.g. hybrid mirrors
    • H01S5/18363—Structure of the reflectors, e.g. hybrid mirrors comprising air layers
    • H01S5/18366—Membrane DBR, i.e. a movable DBR on top of the 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
    • H01S5/10—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]
    • H01S5/18397—Plurality of active layers vertically stacked in a cavity for multi-wavelength emission
    • 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
    • H01S5/20—Structure or shape of the semiconductor body to guide the optical wave ; Confining structures perpendicular to the optical axis, e.g. index or gain guiding, stripe geometry, broad area lasers, gain tailoring, transverse or lateral reflectors, special cladding structures, MQW barrier reflection layers
    • H01S5/2054—Methods of obtaining the confinement
    • H01S5/2059—Methods of obtaining the confinement by means of particular conductivity zones, e.g. obtained by particle bombardment or diffusion
    • H01S5/2063—Methods of obtaining the confinement by means of particular conductivity zones, e.g. obtained by particle bombardment or diffusion obtained by particle bombardment
    • 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
    • H01S5/305—Structure or shape of the active region; Materials used for the active region characterised by the doping materials used in the laser structure
    • H01S5/3095—Tunnel junction
    • 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
    • H01S5/4018—Lasers electrically in series
    • 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
    • H01S5/4087—Array arrangements, e.g. constituted by discrete laser diodes or laser bar emitting more than one wavelength

Definitions

  • This invention relates generally to a vertical cavity apparatus, and more particularly to a vertical cavity apparatus with at least one tunnel junction.
  • DFB distributed feedback
  • VCSELs Vertical Cavity Surface Emitting Lasers emitting in the 1.3 ⁇ m and 1.55 ⁇ m ranges have been visualized as promising candidates for replacing DFBs in telecommunications applications. Due to their extremely short cavity length (on the order of one lasing wavelength), VCSELs are intrinsically single longitudinal mode devices. This eliminates the need for complicated processing steps that are required for fabricating DFB lasers. Furthermore, VCSELs have the advantage of wafer-scale fabrication and testing due to their surface- normal topology.
  • VCSELs suffer material limitations that are negligible in the case of short-wavelength VCSELs but drastically affect the performance of long-wavelength VCSELs.
  • DBRs Bragg Reflectors
  • Another object of the present invention is to reduce loss in a vertical cavity apparatus. Due to the small ⁇ n the relatively thick DBR's result in high diffraction losses. Furthermore, high free-carrier absorption loss limits the maximum achievable reflectivity and the high non-radiative recombination rate increases the electrical current for reaching the lasing threshold.
  • long-wavelength VCSELs have also been manufactured by evaporation of dielectric mirrors as described by S. Uchiyama et al., "Low Threshold Room Temperature Continuous Wave Operation of 1.3 ⁇ m GalnAsP/InP Strained Layer Multiquantum Well Surface Emitting Laser", Electronics Letters, Vol. 32, No. 11, 1996, pp. 1011-13; M.A. Fisher et al., "Pulsed Electrical Operation of 1.5 ⁇ m Vertical-Cavity-Surface-Emitting Lasers", IEEE Photonics Technology Letters, Vol. 7, No. 6, 1995, pp. 608-610 and T. Tadokoro et al., "Room Temperature Pulsed Operation of 1.5 ⁇ m GalnAsP/InP Vertical-Cavity Surface-Emitting Lasers", IEEE Photonics Technology Letters, Vol. 4,
  • Tunneling in GaAs, at an n+/p+ junction is well known (see, for example, N. Holonyak, Jr. and I. A. Lesk, Proc. IRE 48, 1405, 1960), and is generally of interest for its negative resistance.
  • Tunneling in GaAs can be enhanced with an InGaAs transition region (see, for example, T. A. Richard, E. I. Chen, A. R. Sugg. G. E. Hofler, and N. Holonyak, Jr., Appl. Phys. Lett. 63, 3613, 1993), and besides its negative resistance behavior, can be used in reverse bias as a form of "ohmic" contact.
  • a tunnel contact junction can be used in a light emitting semiconductor device as a hole source and makes possible lateral bias currents (electron current) to drive a quantum well heterostructure (QWH) laser without the compromise of the low mobility and large resistive voltage drop of lateral conduction in thin p-type layers.
  • QWH quantum well heterostructure
  • an object of the present invention is to provide a vertical cavity apparatus with improved gain.
  • Another object of the present invention is to reduce loss in a vertical cavity apparatus.
  • Yet another object of the present invention is to provide a vertical cavity apparatus with high efficiency.
  • a further object of the present invention is to provide a vertical cavity apparatus with high sensitivity.
  • Yet another object of the present invention is to reduce resistance in a vertical cavity apparatus.
  • Another object of the present invention is to prevent current spreading in a vertical cavity apparatus.
  • a further object of the present invention is to provide a vertical cavity apparatus with tunnel junctions.
  • Another object of the present invention is to provide a vertical cavity apparatus that cascades multiple pn junctions with a single power source.
  • Yet another object of the present invention is to provide a high power VCSEL.
  • Still a further object of the present invention is to provide a low threshold VCSEL. Another object of the present invention is to provide a VCSEL with a large tuning range.
  • a further object of the present invention is to provide a VCSEL with tunnel junctions.
  • Another object of the present invention is to provide a VCSEL that cascades multiple pn junctions with a single power source.
  • a vertical cavity apparatus that includes a first mirror, a substrate and a second mirror coupled to the substrate. At least a first and a second active region are each positioned between the first and second mirrors. At least a first oxide layer is positioned between the first and second mirrors. At least a first tunnel junction is positioned between the first and second mirrors.
  • Figure 1(a) is a cross-sectional view of a VCSEL structure of the present invention with two active layers, a tunnel junction positioned between the top and bottom mirrors and an oxide layer positioned between the top mirror and the top active layer.
  • Figure 1(b) is a cross-sectional view of a VCSEL structure of the present invention with a tunnel junction positioned between the top and bottom mirrors and an oxide layer positioned adjacent to the bottom mirror.
  • Figure 1(c) is a cross-sectional view of the VCSEL structure of Figure 1(a) with a second tunnel positioned between the top and bottom mirrors.
  • Figure 2 is a cross-sectional view of the VCSEL structure of Figure 1(a) with three active layers, two tunnel junctions and an oxide layer positioned between the top mirror and the top active layer.
  • Figure 3 is a cross-sectional view of the VCSEL structure of Figure 2 with two additional oxide layers, each positioned between a tunnel junction and an active layer.
  • Figure 4 is a cross-sectional view of the VCSEL structure of Figure 2 two partial DBR's, each positioned between a tunnel junction and an active layer.
  • Figure 5 is a cross-sectional view of the VCSEL structure of
  • Figure 4 with two additional oxide layers, each positioned between a tunnel junction and an active layer.
  • Figure 6 is a perspective view of the substrate from the Figure 1(a) through Figure 5 VCSELS with an etched pattern formed on a top or bottom surface.
  • Figure 7 is a cross-sectional view of a top mirror used with the present invention that includes a metallic layer.
  • Figure 8 is a cross-sectional view of a top mirror used with the present invention that is coupled to a tunable filter.
  • Figure 9 is a cross-sectional view of a tunnel junction used with the present invention, illustrating the tunnel junction's opposing first and second sides.
  • Figure 10 is a cross-sectional view of an active layer of the present invention that includes quantum wells and barriers.
  • Figure 11 is a cross-sectional view of a VCSEL structure of the present invention with a tunnel junction positioned between the top mirror and an oxide layer, and the top mirror is an n-doped DBR.
  • Figure 12 is a cross-sectional view of a VCSEL structure of the present invention with a tunnel junction positioned between the top mirror and an oxide layer, and the top mirror is an nid DBR.
  • Figure 13 is a cross-sectional view of a VCSEL structure of the present invention with an oxide layer positioned between the top mirror and the top active layer, and a tunnel junction positioned between the oxide layer and the top active layer.
  • Figure 14 is a cross-sectional view of a VCSEL structure of the present invention with an ion implantation layer.
  • Figure 15 is a cross-sectional view of a VCSEL structure similar to the VCSEL structure of Figure 5 with ion implantation layers substituted for the second and third oxide layers.
  • Figure 16 a cross-sectional view of a VCSEL structure similar to the VCSEL structure of Figure 1 (a) with the inclusion of an etched layer.
  • Figure 17 is a cross-sectional view of a VCSEL structure similar to the VCSEL structure of Figure 5 with etched layers substituted for the second and third oxide layers.
  • Figure 18(a) is a cross-sectional view of the etched layer of Figure 16 with a vertical profile.
  • Figure 18(b) is a cross-sectional view of the etched layer of Figure 16 with a slopped profile
  • Figure 18(c) is a cross-sectional view of the etched layer of Figure
  • Figure 18(d) is a cross-sectional view of the etched layer of Figure 16 with another example of a variable geometric profile.
  • Figure 18(e) is a cross-sectional view of the etched layer of Figure 16 with yet another example of a variable geometric profile.
  • Figure 19 is a cross-sectional view of a vertical cavity structure of the present invention with a fiber grating.
  • Figure 20 is a cross-sectional view of a top mirror used with the present invention that is a fused mirror.
  • Figure 21 is a cross-sectional view of a top mirror used with the present invention that is a cantilever structure.
  • the present invention is a vertical cavity apparatus with a first mirror, a substrate and a second mirror grown on the substrate.
  • the vertical cavity structure of the present invention can be a vertical cavity surface emitting laser, a vertical cavity detector, a vertical cavity modulator, a vertical cavity attenuator, a vertical cavity amplifier, a vertical cavity micromechanical structure, a vertical cavity micromechanical structure with a single support member, a vertical cavity micromechanical structure with at least two support members or a vertical cavity tunable micromechanical structure.
  • the vertical cavity structure is a VCSEL 10.
  • VCSEL 10 is a layered structure with top and bottom mirrors 12 and 14. Light is emitted in a vertical direction that is perpendicular to the planes of the layers.
  • Top and bottom mirrors 12 and 14 are preferably DBR's. The use of DBR's allows to obtain very high reflectivities (>99.5%).
  • First and second active layers 16 and 18 are positioned between top and bottom mirrors 12 and 14.
  • suitable materials for first and second active layers 16 and 18 include but are not limited to
  • At least one tunnel junction 20 and a first oxide layer 22 are each positioned between top and bottom mirrors 12 and 14.
  • Tunnel junction 22 can have a width in the range of 5nm-500nm.
  • Oxide layer 22 can a thickness of less than 0.5 ⁇ m.
  • substrate 24 is also included.
  • Substrate 24 can be made of a variety of materials including but not limited to InP, GaAs and the like.
  • first oxide layer 22 is positioned between top mirror 12 and first active layer 16.
  • first oxide layer 22 is positioned between bottom mirror 14 and second active layer 18.
  • Oxide layer 22 is located in a p type material.
  • tunnel junction 20 When positioned between two active regions tunnel junction 20 increases the gain. When positioned on top of an active region tunnel junction 20 allows low intracavity access resistance and use of low loss mirrors by either using n-doped DBR (for vertical injection) or undoped DBR (intracavity contact) which have less free carrier losses than p-type DBRs.
  • Top mirror 12 can be partially oxidized. Oxidation of top mirror 12 creates a large refractive index difference between adjacent layers. This index difference can drastically increase the stop bandwidth of top mirror 12, and therefore relax the growth accuracy for top mirror 12.
  • the high-contrast, oxidized top mirror 12 reduces the diffraction loss and eliminates the free-carrier-absorption loss.
  • top mirror 12 When top mirror 12 is oxidized, the thickness of high Al-content layers is calculated by taking into account the refractive index and thickness change resulted from the oxidation process.
  • the oxidized part of top mirror 12 is undoped to eliminate free-carrier absorption loss. Oxidation of top mirror 12 can be done in conjunction with the oxidation of the confinement layer.
  • the oxidation process can be conducted in a water-saturated nitrogen ambient, at a temperature between 350 °C to 450 °C.
  • Top and bottom mirrors 12 and 14, as well as the active regions can be grown in the same epitaxial process. This procedure allows full- wafer growth and processing, and therefore significantly reduces the cost of fabricating long-wavelength VCSELs.
  • the lattice relaxed portion of VCSEL 10 can also be grown by a separate epitaxial growth process.
  • the growth temperature for top mirror 12 is preferably less than 500 °C.
  • the lattice relaxed mirror can incorporate a tunnel junction.
  • At least one layer of VCSEL 10 can be grown while the substrate 24 is held stationary and the other layers are grown while substrate 24 is rotated.
  • a second tunnel junction 26 can be optionally included and positioned between bottom mirror 14 and second active layer 18. Additional tunnel junctions increase the gain.
  • a first partial DBR 28 can also be included and positioned between first and second active regions 16 and 18.
  • Figure 2 illustrates an embodiment of VCSEL 10 with a third active region 30.
  • First and second tunnel junctions 20 and 26 are positioned between first, second and third active regions 16, 18 and 30 respectively.
  • first oxide layer 22 is shown as being positioned adjacent to top mirror 12, it will be appreciated that another oxide layer 22 can alternatively be positioned between active layers. Additional active layers can be included. Preferably, no more than ten active layers are included. More preferably the number of active layers is five or less or no more than three.
  • FIG. 3 the inclusion of second and a third oxide layers 32 and 34 are used to reduce current spread. Oxide layers 32 and 34 become insulators and force the current to be funneled in the semiconductor layer (at the center) that is not oxidized.
  • second oxide layer 32 is positioned between first tunnel junction 20 and second active layer 18, and third oxide layer 34 is positioned between second junction
  • first and second partial DBR's 28 and 36 form several FP cavities with different FP wavelengths in order to stabilize the performance in temperature and the wavelength range of tuning.
  • first partial DBR 28 is positioned between first and second active regions 16 and 18.
  • Second partial DBR 36 is positioned between second and third active regions 18 and 30.
  • Second tunnel junction 26 is positioned between second active region 18 and second partial DBR 36.
  • the VCSEL 10 from Figure 4 can also include second and third oxide layers 32 and 34 that are positioned between the first and second partial DBR's 28 and 36 and active regions 18 and 30.
  • Substrate 24 has a given cry stallo raphic orientation. Examples of suitable crystallographic orientations include but are not limited to (001), (311A), (31 IB) and (110). As illustrated in Figure 6, substrate 24 can have an etched pattern 38 formed on a top or bottom surface, where the top surface is adjacent to bottom mirror 14. Substrate 24 can include a dielectric pattern. All or a portion of the substrate 24 layers can be grown using selective area epitaxy.
  • Top mirror 12 can be tunable.
  • a metallic layer 40 can be positioned on the top of top mirror 12.
  • Metallic layer 40 boosts the reflectivity of the DBR.
  • Top mirror 12 can be integrated with a tunable filter 42 ( Figure 8).
  • tunnel junctions 20 and 26 have first and second opposing sides 44 and 46 which are cladding regions.
  • Cladding regions 44 and 46 can be made of the same material, different materials, have different thickness and have different doping profiles and can be non doped.
  • Tunnel junctions 20 and 26 can be uniformly doped and non-uniformly doped.
  • Tunnel junctions 20 and 26 are doped with opposite dopants (i.e., n-type/p-type). Additionally, tunnel junctions 20 and 26 and cladding regions 44 and 46 can be compositionally graded.
  • each active region 16, 18 and 30 includes a least one quantum well, generally denoted as 48 in Figure 10.
  • each active region includes a plurality of quantum wells 48.
  • the quantum wells 48 in each active region 16, 18 and 30 can have different widths, the same widths, different maximum gain wavelengths, the same maximum gain wavelength, different compositions, the same strain and different strain.
  • Quantum wells 48 can be strained quantum wells, tensile strained quantum wells, unstrained quantum wells, compression strained quantum well. All quantum wells 48 can be the same type, different types and combinations.
  • All or some of the different quantum wells 48 in each active region 16, 18 and 30 can have different widths, generate different maximum gain wavelengths, or generate the same maximum gain wavelengths.
  • quantum wells 48 in active region 16 generate a first wavelength, those in active region 18 a different wavelength, those in active region 30 yet another wavelength and so on.
  • the plurality of quantum wells 48 in each active region 16, 18 and 30 can have a plurality of barriers 50. All or a portion of the plurality of barriers 50 can have the same strain or different strains.
  • Each active region 16, 18 and 30 can be a bulk region.
  • the use of a bulk region increases the confinement factor and the modal gain.
  • Bulk regions 52 can be non-doped, uniformly doped or non-uniformly doped. Bulk regions 52 have opposing first and second sides 54 and 56 respectively that can be made of the same material or different materials. The thickness of first and second sides 54 and 56 can be the same or different. First and second sides 54 and 56 can have the same doping profiles, different doping profiles and different widths. Each bulk region 52 can be compositionally graded.
  • tunnel junction 20 allows the current to be injected with a low access resistance than oxide layer 22 which is located in p-regions.
  • first tunnel junction 20 is positioned between top mirror 12 and first oxide layer 22 and is either partially doped or undoped
  • the contact taken laterally on top of tunnel junction 20 can therefore flow in the low resistive n-type material before being converted into holes through the reverse biased tunnel junction 20.
  • the current is then funneled through the oxide aperture in layer 22.
  • the current is injected through the top DBR 12 while in Figure 12 embodiment the current is injected laterally.
  • lateral injection of current permits the use of a non- doped DBR which greatly reduces the free carrier losses.
  • first oxide layer 22 is positioned between top mirror 12 and first tunnel junction 20.
  • first oxide layer 22 is used for index guiding to allow for single mode stability and tunnel junction 20 function is used for current injection through low optical losses materials.
  • the current confinement is done through an implantation step, plasma etching or undercutting.
  • Variations of embodiments illustrated in Figures 11, 12 and 13 include use of a double intracavity contact by putting a lateral contact below active region 16 to allow bottom DBR 14 to be undoped which reduces the losses due to bottom DBR 14. Additionally, the embodiments illustrated in Figures 1 through 14 can also employ the lateral injection of current shown in the Figure 11 and 12 embodiments.
  • Top mirror 12 can be an n-doped DBR.
  • VCSEL 10 includes first tunnel junction 20 and an ion implantation layer 58, each positioned between top and bottom mirrors 12 and 14. Ion implantation is used to locally destroy the conductive properties which enables the creation of a locally conductive area and provides for current localization.
  • first ion implantation layers 58 is substituted for the oxide layers of the Figure 1 through 13 embodiments.
  • Additional ion implantation layers can be included and be positioned between adjacent tunnel junctions and active regions as shown in Figure 15.
  • First oxide layer 22 can also be included and positioned between top mirror 12 and top active region, or between bottom rnirror 14 and the bottom active region (not shown). In the Figure 15 embodiment, there is an amount of index guiding and current confinement.
  • the layers are grown by standard methods, such as molecular beam epitaxy and the like. After this growth a photoresist mask is deposited above the parts where the implantation needs to be prevented. The structure is then exposed to a high energy ion beam. Ions are implanted to depths which are determined by the ion beam energy.
  • VCSEL 10 in another embodiment, illustrated in Figure 16, includes first tunnel junction 20 and a first etched layer 60, each positioned between top and bottom mirrors 12 and 14.
  • first etched layer 60 is substituted for the oxide layers of the Figures 1 through 13 embodiments.
  • etched layers can be included and be positioned between adjacent tunnel junctions and active regions as shown in Figure 17. Etching provides formation of current localization because etched portions are electrical insulators.
  • Each etched layer 60 can have a variety of different profiles. As illustrated in Figures 18 (a), 18(b), 18(c) through 18(e), etched layer 60 can have with respect to a longitudinal axis of substrate 24, a vertical profile, a slopped profile, a variable geometric profile and an undercut profile.
  • One or both of top mirror 12 and bottom mirror 14 can be a lattice relaxed mirror.
  • First tunnel junction 20 is positioned between top and bottom mirrors 12 and 14. Additionally, first oxide layer 22 can be positioned adjacent to top mirror 12 or bottom mirror 14.
  • top and bottom mirrors 12 and 14 can be lattice relaxed mirrors.
  • Lattice relaxed mirrors permit the use of materials with high index contrast, high reflectivities, and low thermal resistively without the constraint of lattice matching.
  • substrate 24 can be made of a lattice defining material such as InP, GaAs and the like.
  • a stack of layers on top of substrate 24 forms bottom mirror 14 and can consist of a combination of material such as InAlGaAs /InAlAs, InGaAsP /InP, AlGaAsSb/AlAsSb, InGaN, GaN, AlGalnAsN/GaAs and the like.
  • Bottom mirror 14 can be formed of alternating layers of InAlGaAs and InAlAs. The refractive index is different between the layers. The number of the alternating layers can be, for example, from 2-2000 in order to achieve the desired reflectivity.
  • Bottom mirror 14 can be lattice matched to the lattice defining material of substrate 24.
  • Bottom 14 can be grown using any epitaxial growth method, such as metal-organic chemical vapor deposition
  • MOCVD molecular beam epitaxy
  • MBE molecular beam epitaxy
  • chemical beam epitaxy and the like.
  • a spacer layer can be deposited on top of bottom mirror 14.
  • the material of spacer layer can be made of InAlGaAs/InAlAs, InGaAsP/InP, AlGaAsSb/AlAsSb, InGaN, GaN, AlGalnAsN/GaAs and the like.
  • the spacer layer can be lattice matched to the lattice defining material of substrate 24.
  • Top mirror 12 can also be a DBR that is grown on top of a confinement layer that can also be considered as part of top mirror 12.
  • the confinement layer and top mirror 12 can be the lattice relaxed portion of VCSEL 10.
  • the lattice mismatch factor may be 0-500%, from the lattice defining material.
  • Top mirror 12 is made of a material such as AlGaAs, InGaP, InGaAsP and the like. In one embodiment, top mirror 12 is made of a set of alternating layers of AlGaAs and GaAs. The high Al-content AlGaAs layers are the low refractive index layers.
  • top mirror 12 and bottom mirror 14 can be a dielectric mirror.
  • First tunnel junction 20 is positioned between top and bottom mirrors 12 and 14.
  • First oxide layer 22 can be positioned adjacent to top mirror 12 or bottom mirror 14.
  • top and bottom mirrors 12 and 14 can be dielectric mirrors. Dielectric materials exhibit large index contrast. Therefore a fewer number of pairs is necessary to obtain high reflectivities.
  • one or both of mirrors 12 and 14 can be a fiber 62 with a grating 64.
  • Suitable fibers 62 include but are not limited to single or multi-mode filters, silicon, plastic and the like.
  • First tunnel junction 20 is positioned between top and bottom mirrors 12 and 14.
  • First oxide layer 22 can be positioned adjacent to top mirror 12 or bottom mirror 14.
  • top and bottom mirrors 12 and 14 can be a fiber 62 with grating 64.
  • Grating 64 can be used to form an external cavity which allows for wavelength tuning by moving fiber 62. Grating 64 also eliminates the need for DBR's and therefore reduces manufacturing time and costs.
  • top and bottom mirrors 12 and 14 is a fused mirror.
  • Wafer fusion has the same advantages as growth of lattice relaxed mirror except that in the wafer fusion case no threading dislocations are present in the mirror.
  • the use of wafer fusion permits the use of a material system for the DBR that is mismatched from the substrate.
  • First tunnel junction 20 is positioned between top and bottom mirrors 12 and 14.
  • First oxide layer 22 can be positioned adjacent to top mirror 12 or bottom mirror 14. With any of the embodiments illustrated in Figures 1 through 17 top and bottom mirrors 12 and 14 can be fused mirrors.
  • top mirror 12 of any of the Figures 1 through 20 can be a cantilever apparatus that uses an electrostatic force that pulls on a cantilever arm. The mechanical deflection resulting from this electrostatic force is used to change the length of a Fabry-Perot microcavity and consequently to the resonance wavelength.
  • top mirror 12 has a cantilever structure consisting of a base 66, an arm 68 and an active head 70.
  • the bulk of cantilever structure may consist of a plurality of reflective layers 72 which form a distributed Bragg reflector (DBR) .
  • Layers 72 can be formed of different materials including but not limited to AlGaAs. Different compositional ratios are used for individual layers 72, e.g.,
  • the topmost layer of layers 72 is heavily doped to ensure good contact with an electrical tuning contact 74 deposited on top of the cantilever structure.
  • the actual number of layers 72 may vary from 1 to 20 and more, depending on the desired reflectivity of the DBR. Furthermore, any suitable reflecting material other than AlGaAs may be used to produce layers 72. Active head 70 is made of layers. However, arm 68 and base 66 do not need to be made of layers.
  • Base 66 can have a variety of different geometric configurations and large enough to maintain dimensional stability of the cantilever structure.
  • the width of arm 68 ranges typically from 2 to 8 microns while its length is 25 to 100 mu m or more.
  • the stiffness of arm 68 increases as its length decreases. Consequently, shorter cantilevers require greater forces to achieve bending but shorter cantilevers also resonate at a higher frequency.
  • the preferred diameter of active head 70 falls between 5 and 40 microns. Other dimensions are suitable.
  • Electrical tuning contact 74 resides on all or only a portion of a top of the cantilever structure. Electrical tuning contact 74 be sufficiently large to allow application of a first tuning voltage Vti.
  • a support 76 rests on a substrate 78 across which a voltage can be sustained.
  • Substrate 78 can include a second DBR 68. Support 76 can be made of the same material as layers 72.
  • a voltage difference between layers 72 and substrate 78 causes a deflection of arm 68 towards substrate 78. If layers 72 and substrate 78 are oppositely doped, then a reverse bias voltage can be established between them.
  • Substrate 78 is sufficiently thick to provide mechanical stability to the entire cantilever apparatus. Inside substrate 78 and directly under active head 70 are one or more sets of reflective layers with each set forming a second DBR.

Landscapes

  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Optics & Photonics (AREA)
  • Semiconductor Lasers (AREA)
  • Photovoltaic Devices (AREA)
  • Superconductor Devices And Manufacturing Methods Thereof (AREA)

Abstract

Un appareil à cavité verticale comprend un premier miroir, un substrat et un second miroir couplé au substrat. Au moins une première et une seconde régions actives sont positionnées chacune entre les premier et second miroirs. Au moins une première couche d'oxyde est positionnée entre les premier et second miroirs. Au moins une jonction à effet tunnel est positionnée entre les premier et second miroirs.
PCT/US2001/006163 2000-02-24 2001-02-26 Appareil a cavite verticale a jonction a effet tunnel WO2001063708A2 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU2001239892A AU2001239892A1 (en) 2000-02-24 2001-02-26 Vertical cavity apparatus with tunnel junction

Applications Claiming Priority (18)

Application Number Priority Date Filing Date Title
US18470600P 2000-02-24 2000-02-24
US60/184,706 2000-02-24
US09/602,817 2000-06-23
US09/603,140 2000-06-23
US09/603,140 US6487230B1 (en) 1998-04-14 2000-06-23 Vertical cavity apparatus with tunnel junction
US09/603,296 2000-06-23
US09/602,444 US6493371B1 (en) 1998-04-14 2000-06-23 Vertical cavity apparatus with tunnel junction
US09/603,227 US6760357B1 (en) 1998-04-14 2000-06-23 Vertical cavity apparatus with tunnel junction
US09/603,239 2000-06-23
US09/602,444 2000-06-23
US09/603,239 US6487231B1 (en) 1998-04-14 2000-06-23 Vertical cavity apparatus with tunnel junction
US09/603,227 2000-06-23
US09/603,242 US6493373B1 (en) 1998-04-14 2000-06-23 Vertical cavity apparatus with tunnel junction
US09/602,817 US6490311B1 (en) 1998-04-14 2000-06-23 Vertical cavity apparatus with tunnel junction
US09/602,454 US6493372B1 (en) 1998-04-14 2000-06-23 Vertical cavity apparatus with tunnel junction
US09/603,296 US6535541B1 (en) 1998-04-14 2000-06-23 Vertical cavity apparatus with tunnel junction
US09/603,242 2000-06-23
US09/602,454 2000-06-23

Publications (2)

Publication Number Publication Date
WO2001063708A2 true WO2001063708A2 (fr) 2001-08-30
WO2001063708A3 WO2001063708A3 (fr) 2002-02-07

Family

ID=27578645

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2001/006163 WO2001063708A2 (fr) 2000-02-24 2001-02-26 Appareil a cavite verticale a jonction a effet tunnel

Country Status (2)

Country Link
AU (1) AU2001239892A1 (fr)
WO (1) WO2001063708A2 (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003073565A2 (fr) * 2002-02-21 2003-09-04 Finisar Corporation Gaassb dope au carbone adapte a une utilisation dans les jonctions tunnel de vcsel
US6888873B2 (en) 2002-02-21 2005-05-03 Finisar Corporation Long wavelength VCSEL bottom mirror
DE102006010728A1 (de) * 2005-12-05 2007-06-06 Osram Opto Semiconductors Gmbh Halbleiterbauelement und Laservorrichtung
EP1950854A1 (fr) 2007-01-25 2008-07-30 OSRAM Opto Semiconductors GmbH Dispositif de mesure et système de mesure
WO2011013498A1 (fr) * 2009-07-28 2011-02-03 Canon Kabushiki Kaisha Laser à émission par la surface comprenant une couche de confinement de courant et plusieurs régions actives
CN107104363A (zh) * 2016-02-23 2017-08-29 朗美通经营有限责任公司 用于垂直腔表面发射激光器的紧凑发射器设计

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5212706A (en) * 1991-12-03 1993-05-18 University Of Connecticut Laser diode assembly with tunnel junctions and providing multiple beams
US5446752A (en) * 1993-09-21 1995-08-29 Motorola VCSEL with current blocking layer offset
WO1998007218A1 (fr) * 1996-08-09 1998-02-19 W.L. Gore & Associates, Inc. Laser a cavite verticale et a emission par la surface muni d'une jonction a effet tunnel
EP0869593A1 (fr) * 1997-04-03 1998-10-07 Alcatel Laser semiconducteur à émission de surface
US5936266A (en) * 1997-07-22 1999-08-10 The Board Of Trustees Of The University Of Illinois Semiconductor devices and methods with tunnel contact hole sources

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05235473A (ja) * 1992-02-26 1993-09-10 Nippon Telegr & Teleph Corp <Ntt> 面型発光素子およびその製造方法
JPH0878773A (ja) * 1994-09-05 1996-03-22 Gijutsu Kenkyu Kumiai Shinjoho Shiyori Kaihatsu Kiko 面発光半導体レーザ

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5212706A (en) * 1991-12-03 1993-05-18 University Of Connecticut Laser diode assembly with tunnel junctions and providing multiple beams
US5446752A (en) * 1993-09-21 1995-08-29 Motorola VCSEL with current blocking layer offset
WO1998007218A1 (fr) * 1996-08-09 1998-02-19 W.L. Gore & Associates, Inc. Laser a cavite verticale et a emission par la surface muni d'une jonction a effet tunnel
EP0869593A1 (fr) * 1997-04-03 1998-10-07 Alcatel Laser semiconducteur à émission de surface
US5936266A (en) * 1997-07-22 1999-08-10 The Board Of Trustees Of The University Of Illinois Semiconductor devices and methods with tunnel contact hole sources

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
GIUDICE G E ET AL: "SINGLE-MODE OPERATION FROM AN EXTERNAL CAVITY CONTROLLED VERTICAL-CAVITY SURFACE-EMITTING LASER" IEEE PHOTONICS TECHNOLOGY LETTERS, IEEE INC. NEW YORK, US, vol. 11, no. 12, December 1999 (1999-12), pages 1545-1547, XP000924491 ISSN: 1041-1135 *
LARSON ET AL: "Micromachined tunable vertical-cavity surface-emitting lasers" ELECTRON DEVICES MEETING, 1996., INTERNATIONAL SAN FRANCISCO, CA, USA 8-11 DEC. 1996, NEW YORK, NY, USA,IEEE, US, 8 December 1996 (1996-12-08), pages 405-408, XP010207572 ISBN: 0-7803-3393-4 *
PATENT ABSTRACTS OF JAPAN vol. 017, no. 691 (E-1479), 17 December 1993 (1993-12-17) & JP 05 235473 A (NIPPON TELEGR & TELEPH CORP), 10 September 1993 (1993-09-10) *
PATENT ABSTRACTS OF JAPAN vol. 1996, no. 07, 31 July 1996 (1996-07-31) & JP 08 078773 A (GIJUTSU KENKYU KUMIAI SHINJOHO SHIYORI KAIHATSU KIKO;FUJITSU LTD), 22 March 1996 (1996-03-22) *

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003073565A3 (fr) * 2002-02-21 2003-12-31 Honeywell Int Inc Gaassb dope au carbone adapte a une utilisation dans les jonctions tunnel de vcsel
US6888873B2 (en) 2002-02-21 2005-05-03 Finisar Corporation Long wavelength VCSEL bottom mirror
WO2003073565A2 (fr) * 2002-02-21 2003-09-04 Finisar Corporation Gaassb dope au carbone adapte a une utilisation dans les jonctions tunnel de vcsel
US8254426B2 (en) 2005-12-05 2012-08-28 Osram Opto Semiconductors Gmbh Surface emitting semiconductor component, and laser device including such component
DE102006010728A1 (de) * 2005-12-05 2007-06-06 Osram Opto Semiconductors Gmbh Halbleiterbauelement und Laservorrichtung
EP1950854A1 (fr) 2007-01-25 2008-07-30 OSRAM Opto Semiconductors GmbH Dispositif de mesure et système de mesure
US7778304B2 (en) 2007-01-25 2010-08-17 Osram Opto Semiconductors Gmbh Measuring arrangement and measuring system
JP2008180719A (ja) * 2007-01-25 2008-08-07 Osram Opto Semiconductors Gmbh 測定装置および測定システム
WO2011013498A1 (fr) * 2009-07-28 2011-02-03 Canon Kabushiki Kaisha Laser à émission par la surface comprenant une couche de confinement de courant et plusieurs régions actives
US8416824B2 (en) 2009-07-28 2013-04-09 Canon Kabushiki Kaisha Surface emitting laser with current constriction layer and multiple active regions
CN107104363A (zh) * 2016-02-23 2017-08-29 朗美通经营有限责任公司 用于垂直腔表面发射激光器的紧凑发射器设计
US10574031B2 (en) 2016-02-23 2020-02-25 Lumentum Operations Llc Compact emitter design for a vertical-cavity surface-emitting laser
CN107104363B (zh) * 2016-02-23 2020-09-25 朗美通经营有限责任公司 垂直腔表面发射激光器及激光器阵列
CN112134141A (zh) * 2016-02-23 2020-12-25 朗美通经营有限责任公司 垂直腔表面发射激光器及激光器阵列
CN112134141B (zh) * 2016-02-23 2021-11-16 朗美通经营有限责任公司 垂直腔表面发射激光器及激光器阵列
US11437784B2 (en) 2016-02-23 2022-09-06 Lumentum Operations Llc Compact emitter design for a vertical-cavity surface-emitting laser

Also Published As

Publication number Publication date
WO2001063708A3 (fr) 2002-02-07
AU2001239892A1 (en) 2001-09-03

Similar Documents

Publication Publication Date Title
US6760357B1 (en) Vertical cavity apparatus with tunnel junction
US6535541B1 (en) Vertical cavity apparatus with tunnel junction
US6487230B1 (en) Vertical cavity apparatus with tunnel junction
US5991326A (en) Lattice-relaxed verticle optical cavities
Chang-Hasnain et al. Multiple wavelength tunable surface-emitting laser arrays
US5879961A (en) Method for increasing laser efficiency in a vertical-cavity surface emitting laser
US5903590A (en) Vertical-cavity surface-emitting laser device
US6542531B2 (en) Vertical cavity surface emitting laser and a method of fabrication thereof
Tai et al. 90% coupling of top surface emitting GaAs/AlGaAs quantum well laser output into 8 µm diameter core silica fibre
US6782021B2 (en) Quantum dot vertical cavity surface emitting laser
Sugihwo et al. Micromachined widely tunable vertical cavity laser diodes
US7288421B2 (en) Method for forming an optoelectronic device having an isolation layer
US5712865A (en) Temperature-insensitive vertical-cavity surface-emitting lasers and method for fabrication thereof
US6493373B1 (en) Vertical cavity apparatus with tunnel junction
US20180241177A1 (en) Tunnel junction for gasa based vcsels and method therefore
Syrbu et al. 1.5-mW single-mode operation of wafer-fused 1550-nm VCSELs
Karim et al. 1.55-/spl mu/m vertical-cavity laser arrays for wavelength-division multiplexing
Huffaker et al. Intracavity contacts for low-threshold oxide-confined vertical-cavity surface-emitting lasers
US6882673B1 (en) Mirror structure for reducing the effect of feedback on a VCSEL
US6021146A (en) Vertical cavity surface emitting laser for high power single mode operation and method of fabrication
Illek et al. Low threshold lasing operation of narrow stripe oxide-confined GaInNAs/GaAs multiquantum well lasers at 1.28 µm
US6493372B1 (en) Vertical cavity apparatus with tunnel junction
US6487231B1 (en) Vertical cavity apparatus with tunnel junction
Augustin et al. Controlled polarization switching in VCSELs by means of asymmetric current injection
US6493371B1 (en) Vertical cavity apparatus with tunnel junction

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A2

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CR CU CZ DE DK DM DZ EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT TZ UA UG US US US US US US US US US UZ VN YU ZA ZW

AL Designated countries for regional patents

Kind code of ref document: A2

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE TR BF BJ CF CG CI CM GA GN GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
AK Designated states

Kind code of ref document: A3

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CR CU CZ DE DK DM DZ EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT TZ UA UG US US US US US US US US US UZ VN YU ZA ZW

AL Designated countries for regional patents

Kind code of ref document: A3

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE TR BF BJ CF CG CI CM GA GN GW ML MR NE SN TD TG

REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase in:

Ref country code: JP