WO2003010568A1 - Ensemble de lasers regules accordables - Google Patents

Ensemble de lasers regules accordables Download PDF

Info

Publication number
WO2003010568A1
WO2003010568A1 PCT/US2001/046591 US0146591W WO03010568A1 WO 2003010568 A1 WO2003010568 A1 WO 2003010568A1 US 0146591 W US0146591 W US 0146591W WO 03010568 A1 WO03010568 A1 WO 03010568A1
Authority
WO
WIPO (PCT)
Prior art keywords
optical
transmission apparatus
lasers
array
optical transmission
Prior art date
Application number
PCT/US2001/046591
Other languages
English (en)
Inventor
Bardia Pezeshki
John Heanue
Ed Vail
Original Assignee
Santur Corporation
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
Application filed by Santur Corporation filed Critical Santur Corporation
Publication of WO2003010568A1 publication Critical patent/WO2003010568A1/fr

Links

Classifications

    • 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
    • G02B6/35—Optical coupling means having switching means
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
    • G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
    • G02B26/0816—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
    • G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
    • G02B26/0816—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements
    • G02B26/0833—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
    • G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
    • G02B26/0816—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements
    • G02B26/0833—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD
    • G02B26/0841—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD the reflecting element being moved or deformed by electrostatic means
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
    • G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
    • G02B26/0816—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements
    • G02B26/0833—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD
    • G02B26/085—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD the reflecting means being moved or deformed by electromagnetic means
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
    • G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
    • G02B26/0816—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements
    • G02B26/0833—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD
    • G02B26/0858—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD the reflecting means being moved or deformed by piezoelectric means
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
    • G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
    • G02B26/0816—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements
    • G02B26/0833—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD
    • G02B26/0866—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD the reflecting means being moved or deformed by thermal means
    • 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
    • G02B6/35—Optical coupling means having switching means
    • G02B6/3598—Switching means directly located between an optoelectronic element and waveguides, including direct displacement of either the element or the waveguide, e.g. optical pulse generation
    • 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
    • G02B6/42—Coupling light guides with opto-electronic elements
    • G02B6/4201—Packages, e.g. shape, construction, internal or external details
    • G02B6/4204—Packages, e.g. shape, construction, internal or external details the coupling comprising intermediate optical elements, e.g. lenses, holograms
    • G02B6/4206—Optical features
    • 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
    • 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
    • G02B6/35—Optical coupling means having switching means
    • G02B6/3502—Optical coupling means having switching means involving direct waveguide displacement, e.g. cantilever type waveguide displacement involving waveguide bending, or displacing an interposed waveguide between stationary waveguides
    • G02B6/3508—Lateral or transverse displacement of the whole waveguides, e.g. by varying the distance between opposed waveguide ends, or by mutual lateral displacement of opposed waveguide ends
    • 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
    • G02B6/35—Optical coupling means having switching means
    • G02B6/351—Optical coupling means having switching means involving stationary waveguides with moving interposed optical elements
    • G02B6/3512—Optical coupling means having switching means involving stationary waveguides with moving interposed optical elements the optical element being reflective, e.g. mirror
    • 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
    • G02B6/35—Optical coupling means having switching means
    • G02B6/351—Optical coupling means having switching means involving stationary waveguides with moving interposed optical elements
    • G02B6/3524—Optical coupling means having switching means involving stationary waveguides with moving interposed optical elements the optical element being refractive
    • G02B6/3528—Optical coupling means having switching means involving stationary waveguides with moving interposed optical elements the optical element being refractive the optical element being a prism
    • 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
    • G02B6/35—Optical coupling means having switching means
    • G02B6/354—Switching arrangements, i.e. number of input/output ports and interconnection types
    • G02B6/3554—3D constellations, i.e. with switching elements and switched beams located in a volume
    • G02B6/3558—1xN switch, i.e. one input and a selectable single output of N possible outputs
    • 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
    • G02B6/35—Optical coupling means having switching means
    • G02B6/3564—Mechanical details of the actuation mechanism associated with the moving element or mounting mechanism details
    • G02B6/3568—Mechanical details of the actuation mechanism associated with the moving element or mounting mechanism details characterised by the actuating force
    • G02B6/3572—Magnetic force
    • 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
    • G02B6/35—Optical coupling means having switching means
    • G02B6/3586—Control or adjustment details, e.g. calibrating
    • G02B6/359—Control or adjustment details, e.g. calibrating of the position of the moving element itself during switching, i.e. without monitoring the switched beams
    • 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
    • H01S5/005—Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/02—Structural details or components not essential to laser action
    • H01S5/022—Mountings; Housings
    • H01S5/023—Mount members, e.g. sub-mount members
    • H01S5/02325—Mechanically integrated components on mount members or optical micro-benches
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/10—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
    • H01S5/12—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 the resonator having a periodic structure, e.g. in distributed feedback [DFB] lasers
    • H01S5/1206—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 the resonator having a periodic structure, e.g. in distributed feedback [DFB] lasers having a non constant or multiplicity of periods
    • H01S5/1215—Multiplicity of periods
    • 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

  • the present invention relates generally to lasers and in particular to tunable lasers used in telecommunications systems.
  • Lasers are widely used in high speed data communication devices such as multi- wavelength fiber optic communication links.
  • WDM wavelength division multiplexed
  • DFB lasers contain a waveguiding structure fabricated in an active semiconductor, where a continuous grating runs through the device and determines the wavelength of operation.
  • these devices are high power, have excellent single wavelength characteristics (side-mode suppression ratio), and are extremely stable over time.
  • DFB lasers generally operate at fixed wavelengths, and are very difficult to tune to other wavelengths. Though slight changes in wavelength can be realized via thermal effects, tuning DFB lasers by large amounts, to cover a large part of a communication band is often not possible. As such, in order to provide a large, gradual and varied tuning range, generally a large number of DFB lasers fixed at different wavelengths are stocked, along with multiple spare DFB lasers. However, system reconfiguration becomes more complex in order to accommodate multiple DFB lasers.
  • the present invention relates to providing one of many transmission wavelengths from a simple compact package, useful for multiple wavelength communication in fiber optic links, hi one embodiment the present invention comprises an optical transmission apparatus.
  • the optical transmission apparatus comprises an array of lasers, an array of mirrors, and an optical output. Each mirror in the array of mirrors is movable such that light from a laser from the array of lasers directed to the mirror is directed to the optical output.
  • the present invention comprises an optical transmission apparatus.
  • the optical transmission apparatus comprises an array of lasers, a lens collimating light from the laser in the array of lasers, and an optical output.
  • the invention further comprises a movable mirror movable to receive light collimated by the lens from any of a plurality of lasers in the array of lasers, the mirror reflecting the light back to the lens which passes the light to the optical output.
  • the invention comprises a mirror positionable to reflect light that normal incidence from any one of a plurality of lasers in the arrays of lasers to the optical element.
  • FIG. 1 illustrates one embodiment of an optical transmission apparatus having an individually addressable multi-wavelength laser array directly coupled to a 1:N micro- mechanical switch;
  • FIG. 2 illustrates another embodiment of an optical transmission apparatus having a micro-lens array used to collimate the beams from the laser array and one particular beam is selected by an array of movable mirrors;
  • FIG. 2 A illustrates one embodiment of an optical transmission apparatus of FIG. 2 having a servo control loop;
  • FIG. 3 illustrates another embodiment of an optical transmission apparatus having a tilting mirror where a single lens acts both to collimate and focus the beam;
  • FIG. 3 A illustrates one embodiment of an optical transmission apparatus of FIG. 3 having a servo control loop
  • FIG. 4 illustrates another embodiment of an optical transmission apparatus where the lasers in a laser array are not made parallel to one another, but at varying angles;
  • FIG. 5 illustrates another embodiment of an optical transmission apparatus with a movable optical element
  • FIG. 6 illustrates a side view of the optical transmission apparatus illustrated in
  • FIG. 5 A first figure.
  • FIG. 7 illustrates another embodiment of an optical transmission apparatus with at least one movable mirror
  • FIG. 8 illustrates another embodiment of an optical transmission apparatus in which light is provided to a fiber via a movable element being dynamically controlled
  • FIG. 9 illustrates one embodiment of a moveable mirror
  • FIG. 10 illustrates one embodiment of an optical transmission apparatus in which light is provided to a fiber via a sliding waveguide
  • FIG. 11 illustrates another embodiment of an optical transmission apparatus in which light is provided to a fiber via a selective multiplexer
  • FIG. 12 illustrates a further single lens embodiment in accordance with aspects of the present invention
  • FIG. 13 illustrates a further embodiment using an electro-optic beam steering element
  • FIG. 14 illustrates a further embodiment using an acousto-optic beam steering element.
  • FIG. 1 shows an array of single wavelength lasers, such as distributed feedback (DFB) lasers, on a semiconductor substrate.
  • each of the lasers is a single wavelength, not all of the lasers operate at the same wavelength. Indeed in a preferred embodiment, the lasers each output light at different wavelengths.
  • the array of lasers comprises a number of independently addressable lasers 7.
  • Each laser has a separate contact pad 3 from which current is injected into the laser.
  • Each laser is designed to operate at a different lasing wavelength, by, for example, varying the grating pitch in the laser or adjusting the effective index of the optical mode through varying the stripe width or the thickness of the layers that compose the laser.
  • the laser emits radiation with a specific wavelength and from a particular position on the chip, as represented by the arrows 9.
  • one laser is operated at a time, depending on the desired wavelength.
  • the radiation or light from the lasers is transmitted to a micro- mechanical optical switch or switching element 11.
  • the switching element has a number of states.
  • one of the input optical beams i.e., light from one of the lasers
  • the entire assembly is packaged together on one submount 19.
  • the fabrication of multi-wavelength laser arrays is relatively well known in the art.
  • a number of techniques can be used, such as directly- written gratings with electron beam lithography, stepping a window mask during multiple holographic exposures, UV exposure through an appropriately fabricated phase mask, or changing the effective index of the mode of the lasers.
  • a controlled phase shift is also included in the laser or gain/loss coupling is used in the grating.
  • the wavelength of such lasers can be accurately controlled through dimensional variables, and varied across the array.
  • the switching element 11 in one embodiment, comprises multiple mirrors that intercept each input optical beam and deflect the optical beam to an optical output. As such, to select a particular laser, the appropriate mirror is adjusted to receive and deflect the optical beam to the optical output.
  • FIG. 2 illustrates one such switching element with a laser array 5.
  • a set of microlenses 21 is provided to collimate diverging beams from the laser elements of the laser array to form a collimated beam 203.
  • the switch or switching element 201 comprises an array of mirrors 23 that are individually positionable. The mirrors are retracted by electrostatic comb actuators 27 and pushed forward by springs 29. In another embodiment, the mirrors are pushed forward by springs 29 and retracted by electrostatic comb actuators 27.
  • a particular mirror is positioned to deflect the collimated beam from a corresponding laser of the array of lasers.
  • a single lens 25 focuses the deflected and collimated beam into an output fiber 15.
  • the switch is a 1:N switch and, in various embodiments, is manufactured using surface micromachining, deep silicon etching, or other processes.
  • the actuation mechanism, the actuators and/or springs can be electrostatic, as shown, but are thermal or magnetic in other embodiments.
  • a current is provided to a laser element of the laser array, e.g., laser element 7, and thereby the laser element emits light.
  • a mirror of the array of mirrors, e.g., mirror 205, that corresponds to the selected laser element is identified.
  • the springs coupled to the corresponding mirror pushes the mirror forward.
  • the mirror is pushed past an initial position occupied by the other mirrors or pushed out of the switching element 201.
  • the light from the laser element is collimated by a corresponding microlens and strikes the actuated mirror.
  • the mirror reflects the light to the lens 25 which focuses the light into the optical fiber 15. Once the light from the laser element is no longer needed, the mirror is retracted by the actuators.
  • the mirror is retracted when another laser element is selected.
  • the corresponding mirror is identified and positioned to cause the light from the selected laser element to be directed into the optical fiber. Any mirror not used to direct the light from the selected laser element to the fiber is positioned so as not to obstruct the optical path of the light from the selected laser element to the corresponding mirror and to the optical fiber.
  • FIG. 3 illustrates a further embodiment in accordance with the invention.
  • an optical beam from a particular laser element 7 of the laser array 5 is collimated with a fixed lens 31.
  • the light beam from the laser is initially diverging and is collimated by the fixed lens.
  • the collimated beam from the fixed lens strikes a movable mirror 33.
  • the movable mirror is nearly perpendicular to the beam, close to normal incidence, and reflects the beam back to the lens.
  • the lens receives the reflected light beam and focuses the beam into an output fiber.
  • the fiber is positioned to receive the light at a location approximate the laser array, and in a direction substantially parallel to laser elements forming the laser array.
  • optical isolators are positioned in the optical path to avoid reflections back into the lasers, which may have deleterious effects.
  • micro-mechanical tip/tilt mirrors such as the mirror 33
  • Both surface micromachining techniques and bulk silicon etching have been used to make such mirrors.
  • the precision required for the present invention is considerably less than that of large cross connect switches, as the beams travel a few millimeters, when the embodiments described herein are packaged in standard butterfly packages, rather than tens of centimeters in the switches. With the laser modes closely spaced in the laser array, the pointing requirement for the optical apparatus are considerably reduced.
  • the output fiber is placed laterally to the laser array, such that at different angles of the mirror, the light from different laser elements are directed to the fiber.
  • the fiber is situated slightly above or below the laser array, with the mirror tilted slightly in another dimension, so that the reflected beam focuses onto the fiber.
  • the fiber is shown to be the same distance away from the lens as the laser array, the two distances can be varied such that the system has non-unity magnification.
  • the fiber in one embodiment, is a lensed fiber. The lensed fiber provides better coupling to a semiconductor source, e.g., a laser, with an optical system of unity magnification.
  • a graded refracted index (GRTN) lens is used instead of the convex lens 31 .
  • the lens is moved to a different position to optimize the fiber coupling of the light beam from the laser element selected into the optical fiber.
  • the position of the lens is controlled by a servo loop, such that the fiber coupled power is always maximized. Active alignment in such a system can be avoided if the lens 31 (FIG. 3) or lens 21 (FIG. 2) is moved in two dimensions.
  • the package can be put together passively, with coarse accuracy, and as such, the servo loop can be optimized electronically both in the lateral and vertical position of the lens for maximum coupling.
  • these two positions are the most sensitive alignment parameters.
  • all the components could be soldered in a package using a coarse pick-and-place machine, and the servo loop maintains optimum alignment, obviating the need for operator-assisted active alignment.
  • FIG. 2A and FIG. 3A illustrate such embodiments.
  • a wavelength locker is coupled to the fiber by a tap.
  • the wavelength locker is inline with the fiber.
  • the wavelength locker determines the strength or power of light transmitted at the fiber, and provides a signal indicative of the signal strength to a controller.
  • the light from the tap is provided to a photodetector.
  • the photodetector produces a signal that is proportional to the output power of the light from the tap and is provided to the controller.
  • the controller adjusts the mirror (for the embodiment of FIG. 3A) or selects a mirror (for the embodiment of FIG. 2A) based on previous signals provided by the wavelength locker or an initial calibration.
  • the controller maintains a lookup table of mirror positions in conjunction with the selection of each of the lasers in the laser array. Based on the values in the lookup table, the controller determines which direction the mirror should be moved to provide optimal output power. Thus, as appropriate, the controller produces a control signal to move the mirror along, for example, a first axis or a second axis, with the second axis being perpendicular to the first axis.
  • the mirror in one embodiment, is continually commanded to wander and the output power monitored to compensate for movement of components of the package, thermal effects and other causes of potential misalignment and thereby provide maximum output power.
  • FIGs. 1-3 show the laser element or stripe perpendicular to the facet, this need not necessarily be so.
  • DFB lasers where the feedback into the cavity comes from the grating and not the facet, device performance improves with an angled facet. Angling the stripe relative to the facet reduces the effective reflectivity of the facet and prevents instabilities in the mode structure of the laser.
  • the semiconductor chip is tilted with respect to the rest of the optics, but the optical paths remain relatively unchanged.
  • the first lens causes the beams from the different lasers to be collimated, parallel and shifted with respect to each other.
  • the laser array chip 41 comprises a number of different laser elements 43, all angled or tilted with respect to one another. As such, each laser element emits an optical beam at a different angle. A particular laser element is selected and the optical beam emitted is incident on a collimating lens 45. Since the beam originates from the focal point of the lens, the beam is collimated and redirected parallel to the optical axis of the lens. As such, the beams from each of the lasers are collimated and are parallel to each other, but shifted vertically. An optical element 47 shifts the beams back into the center of the optical axis to fall upon a focusing lens 49 and coupled to the output fiber 15.
  • the optical element in one embodiment, is a solid high index block that shifts the image, and is moveable to allow for correct selection of the output from a particular laser of the laser array.
  • other components are used to shift the beam laterally, such as two mirrors with a fixed angle to each other and rotated simultaneously, or a wedge that is inserted into the paths of the optical beams and moves linearly into the beams.
  • the laser array itself could be moved laterally to change the coupling into the fiber.
  • the fiber could be moved.
  • moving larger objects, such as the laser array or the fiber requires more force.
  • piezoelectric transducers or set screws are employed in various embodiments.
  • the translatable element is an optical element 501.
  • the optical element in one embodiment, is a silicon component with volume removed from one side to form two opposing angled sides. The two opposing angled sides are coated with a reflective substance, forming mirrors 55 and 57.
  • the two angled mirrors couple a light beam 505 from one laser element or stripe 7 from an array of laser stripes 5 via a lens 503 into a fiber 15.
  • the optical element is translated in a direction that is perpendicular to the length of the array of laser stripes to couple light from another laser stripe, e.g., laser stripe 51, to the fiber.
  • the mirrors in the embodiment described, are separate. However, in another embodiment, the mirrors are two sides of a prism. For example, the prism may resemble the shape of the material removed from the optical element, with the exterior of the angled sides coated with a reflective material depending on the extent of the internal reflection of the prism. In another embodiment, the mirrors are mounted on a common movable element or separately provided on a moveable element but commonly coupled together. In one embodiment, the distance of translation of the optical element or the moving mirrors is half the separation of the laser stripes at the ends of the array.
  • the distance between the end stripes is 90 microns and thus, the range of travel of the moving mirrors is about 45 microns.
  • the length of the array also determines the minimum size of the mirrors.
  • the projected length of the mirror on the array is at least half the length of the array.
  • the projected length of the mirror is about at least 45 microns. With a 45 degree angle as drawn, the actual width of the mirror is about 45 microns divided by the sin of 45 degrees, or about 64 microns.
  • the mirrors or prism can be very small.
  • the element is also rotatable about an axis formed along a line of the linear translation.
  • one or more additional moving two-mirror or prism assembly are used. The range of movement in many cases is less in the out-of-plane direction than in the in-plane direction described above.
  • the clearance or separation between the chip and the fiber should account for the angular divergence of the beam.
  • This issue is illustrated in FIG. 6 using a side view of an optical apparatus.
  • a light beam 61 is emitted from a laser stripe 7 mounted on a submount 65.
  • the light beam is reflected back by two mirrors 61 and 63.
  • the emitted light beam has a certain, vertical divergence angle, as illustrated by arrows 69a and 69b which may be up to 60 degrees.
  • vertical separation 601 from all components of the chip or package to the center of the light beam out to an optical output is sufficiently large to compensate for the divergence angle of the light beam.
  • the separation is similar to the length of the submount, on the order of a few millimeters.
  • the mirrors are moved simultaneously, in a similar manner, as previously described in reference to FIG. 5.
  • laser stripe selection is achieved in another embodiment by movement of either mirror 75 or mirror 77, thereby simplifying the mounting or fabrication of the moving mirror. As such, one of the mirrors remains fixed. In this embodiment, the optical path length to the fiber is different for each laser stripe, so different optics are used to ensure that the light is always adequately focused.
  • the two angled mirrors 75 and 77 are used to couple a light beam 73 from a laser stripe 7 of the array of lasers 5 via lenses
  • the mirror 77 is translated in a direction 79 to select another laser stripe, e.g., laser stripe 703.
  • the movement of the moving mirror can be in the direction shown, perpendicular to the plane of the mirror, or in other directions, for example, parallel to or perpendicular to the direction of the light beam incident upon it.
  • the moving mirror is mounted on a moving actuator or in other embodiments, the moving mirror is a moving element itself, for example, a micro- machined silicon actuator with a reflective coating.
  • the lenses 71 collimates a light beam from a laser stripe, so that the second lens 701 focuses the light into the optical output 15 independent of the varying optical path between the two lenses.
  • the mirror 705 is the moving mirror and the mirror 703 is fixed.
  • the total optical path length to the fiber from the exit facet of the laser is constant no matter which laser stripe is selected, such that the fiber and any focusing lens or lenses can remain stationary while maintaining optimum coupling.
  • fiber coupling is dynamically controlled through a feedback loop, such as previously described or described in the aforementioned patent application Laser and Fiber Coupling Control. Electronic control of fiber coupling reduces the cost of the initial active alignment step in the packaging as well as enables an electronically selectable functionality.
  • FIG. 8 shows a schematic of one embodiment of an optical system with a magnetic control element.
  • a laser array chip 5 comprises a number of different laser elements 7, each of which has a different set of characteristics.
  • the light from one particular laser element is used and directed by the optical train to an output fiber 15.
  • the light from the laser element is collimated by a fixed focusing lens 81 and impinges on a mirror 83 whose angle is varied electronically.
  • the light is focused by a second lens 805 and is coupled to the output fiber.
  • the mirror's rotation angle is adjusted both to select the beam of a particular laser, and also to maintain the optimal coupling to the optical output.
  • the tilting mirror is shown to be moved magnetically. Two magnets 85 attached to the rear of the mirror are positioned with solenoids 87.
  • a control current applied through wire 89 controls the magnetic field which pulls one magnet into the solenoid and pushes the other magnet out. Together with a fixed pivot point 803 and a spring 801, the angle of the mirror is controlled using the control current.
  • electro-static, thermal, piezoelectric, or any variety of techniques are used to control the position of the optical elements, and thereby influence the optical coupling in various embodiments.
  • motion occurs in more than one dimension.
  • the mirror tilts in another direction, i.e., out of the plane of the drawing.
  • the lenses in one embodiment are also positionable along the direction of the optical axis for optimal focus.
  • FIG. 9 An alternative magnetically induced actuator is shown in FIG. 9.
  • a micro-mirror 91 is restrained by two hinges 93a,b on either sides of the micro-mirror. Patterned on the surface is a coil 97. The coil generates a magnetic field when an electric current is passed between contacts 95.
  • the micro-mirror is placed in a constant external field 99, such that the interaction between the two fields torques the mirror about the two hinges.
  • Such galvanic mirrors are commonly fabricated in the art. Together, with electrostatic actuation in the other direction, they can be used to deflect the optical beams from an array of lasers and select a single beam to be coupled to a fiber.
  • the mirror 91 could be fabricated out of or contain a magnetic material such as nickel. As a result, no lithographically produced coils would be needed.
  • the deflection angle can be controlled by varying the strength of the external magnetic field produced by an electro-magnet.
  • FIG. 10 utilizes a sliding waveguiding layer to select the output of a particular laser to be coupled to the fiber.
  • a laser array 5 contains a number of laser elements 7.
  • the array is coupled to a planar waveguide chip 101 that has a series of curved waveguides 103 lithographically patterned into the chip.
  • the waveguides are constructed using silica-on-silicon technology, or alternatively silicon-on-insulator (SOI) technology.
  • SOI silicon-on-insulator
  • the entire section of curved waveguides is configured to move laterally.
  • Various other displacement mechanisms including those discussed herein, may also be used.
  • an output waveguide 105 On the other side of the movable planar waveguide section is an output waveguide 105, e.g., an optical fiber.
  • a different curved waveguide connects one laser element of the laser array to the output waveguide.
  • a tunable source can be realized by selecting a laser of an appropriate wavelength, and then translating the sliding waveguide section such that the selected laser's output is coupled to the output waveguide.
  • FIG. 11 the planar waveguide includes a wavelength selective component 113, such as an arrayed waveguide grating (AWG).
  • AWG arrayed waveguide grating
  • an AWG is provided by integrating a pair of star couplers with a diffraction grating comprised of unequal length waveguides. Appropriately varying the length of the waveguides for input beams of predetermined wavelengths, and appropriate design of the couplers, allows for a plurality of input beams to be coupled to a single output.
  • a laser array 5 contains lasers of different wavelengths, e.g., laser element 7.
  • the wavelength selective component or multiplexer includes a series of wavelength channels at its input. Each wavelength channel corresponds to a particular laser having a particular wavelength. As all the wavelength channels of the multiplexer are aligned to the laser array, all the beams from each laser element can be combined simultaneously into the optical output 115.
  • the lasers can be modulated directly or, in one embodiment, integrated electroabsorption modulators 111 are fabricated in the chip. Although a separate wavelength selective multiplexer is shown, such devices are readily fabricated in InP and the entire assembly, lasers, modulators and a AWG, can be integrated together. However, for thermal tuning of the device, the temperature dependent characteristics of the multiplexer 113 should be carefully matched to that of the laser array, so that the wavelength of the lasers and the pass characteristics of the AWG move together. Additionally, when all the lasers are operated simultaneously, thermal cross talk between the lasers should be minimized by, preferably, spacing the lasers apart. Also the radio frequency cross talk radiated and capacitively coupled between the lines should be minimized.
  • FIG. 12 illustrates single-lens imaging embodiment 1200 of the present invention in which a single lens 81 is employed to both collimate and focus optical beam 99 from particular lens element 7 of laser array 5 onto mirror 83.
  • lens 81 it is desirable to select the magnification of lens 81 to maximize optical beam coupling efficiency into fiber 15.
  • mirror 83 in the back focal plane of lens 111, which in one embodiment is a single collimating-focus lens, the mirror size and deflection range that can be used in single-lens imaging embodiment 1200 would be approximately the same as would be used in a functionally-comparable collimated beam imaging embodiment, provided the effective focal length for the imaging lens is approximately that of the collimating lens.
  • single-lens imaging embodiment 1200 can be advantageous, for example, where it is desirable to include, for example, a semiconductor or a modulator with the single-lens imaging device.
  • substantially mechanical beam steering techniques are primarily discussed above, in various embodiments other beam steering techniques are used. Such embodiments include, without limitation, electro-optic (EO) and acousto-optic (AO) beam steering techniques.
  • EO and AO deflectors essentially lack moving parts, thereby rendering designs incorporating these devices more robust.
  • FIG. 13 illustrates an EO deflector embodiment 1300 of the present invention, in which EO deflector 120 is used to steer the optical beam.
  • optical beam 99 from particular lens element 7 of laser array 5 is collimated with fixed lens 121, and then transmitted to EO deflector 120 which steers collimated beam 125 to the focusing lens 128.
  • Focusing lens 128, in turn, directs the axis of the cone of light 98 to be focused on, and maximally coupled to, fiber 15.
  • a electro-optic modulator exhibits a predetermined amount of birefringence upon application of a voltage to a suitable crystalline material producing the birefringent effect.
  • Suitable materials include, without limitation, barium sodium niobate, lithium niobate, potassium dihydrogen phosphate, ammonium dihydrogen phosphate, and nitrobenzene.
  • the crystalline material may be provided in different structures, in the present embodiment, it is desirable that a prism be used as the EO modulator.
  • the predetermined applied voltage alters the index of refraction of the prism by a predetermined amount, thereby selectively altering the propagation direction of a beam there through.
  • FIG. 14 illustrates an AO embodiment 1400 of the present invention, in which AO deflector 130 is used to steer the optical beam.
  • optical beam 99 from particular lens element 7 of laser array 5 is collimated with fixed lens 131, and then transmitted to AO modulator 130, which steers collimated beam 135 to the focusing lens 138.
  • Focusing lens 138 directs the axis of the cone of light 98 to be focused on, and maximally coupled to, fiber 15.
  • an optical beam is diffracted by a column of sound passing through a suitable AO medium.
  • An acousto- optic interaction occurs in an optical medium, for example, when an acoustic wave and a laser beam are present in the medium.
  • an acoustic wave When an acoustic wave is launched into the optical medium, it generates a refractive index wave that behaves like a sinusoidal grating.
  • a piezoelectric transducer to the AO medium, because a predetermined voltage applied to such a transducer can generate an acoustic wave with selectable characteristics causing a predetermined deflection of the optical beam passing through the selected AO material.
  • Materials commonly used for visible light and near- infrared regions can include dense flint glass, tellurium oxide, chalcogenide glass or fused quartz. In the infrared region, germanium can be used.
  • germanium For high frequency signal processing devices, for example, lithium niobate and gallium phosphide may be suitable. Relative to an EO deflector, an AO deflector tends to have less bandwidth but, at the same time, generally requires a lower operating voltage and demands less power.
  • the present invention therefore provides a tunable laser.
  • the invention has been described with respect to certain specific embodiments, it should be recognized that the invention may be practiced otherwise than as specifically described. Accordingly, the invention should be considered as that defined by the attached claims and their equivalents, as well as claims supported by this disclosure.

Abstract

L'invention concerne une puce à semi-conducteur comprenant plusieurs éléments laser différents (43). Un élément laser particulier est sélectionné et un élément optique pouvant être positionné pour que la lumière frappe une lentille collimatrice (45). Un élément optique (47) redécale le faisceau vers le centre de l'axe optique afin que ledit faisceau frappe une lentille de focalisation (49) et ledit élément est couplé à une fibre de sortie (15).
PCT/US2001/046591 2001-07-24 2001-10-31 Ensemble de lasers regules accordables WO2003010568A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US30755901P 2001-07-24 2001-07-24
US60/307,559 2001-07-24

Publications (1)

Publication Number Publication Date
WO2003010568A1 true WO2003010568A1 (fr) 2003-02-06

Family

ID=23190276

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2001/046591 WO2003010568A1 (fr) 2001-07-24 2001-10-31 Ensemble de lasers regules accordables

Country Status (1)

Country Link
WO (1) WO2003010568A1 (fr)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1376191A1 (fr) * 2002-06-21 2004-01-02 Nikon Corporation Système d' actionnement d' un miroir deformable
WO2006071943A1 (fr) * 2004-12-28 2006-07-06 Intel Corporation Pilotes de lasers a option de choix de plots integres permettant de selectionner des courants
JP2007529637A (ja) * 2004-02-27 2007-10-25 ザ プロクター アンド ギャンブル カンパニー 多重使用布地コンディショニング物品のための凹面組成物担体
EP2879387A1 (fr) * 2013-10-31 2015-06-03 Christie Digital Systems Canada, Inc. Système et appareil de distribution de lumière dynamique
WO2015200271A1 (fr) * 2014-06-25 2015-12-30 TeraDiode, Inc. Systèmes et procédés pour systèmes laser à produit de paramètres de faisceau variable
US9435964B2 (en) 2014-02-26 2016-09-06 TeraDiode, Inc. Systems and methods for laser systems with variable beam parameter product
US10914902B2 (en) 2014-02-26 2021-02-09 TeraDiode, Inc. Methods for altering properties of a radiation beam
US20210119404A1 (en) * 2017-11-09 2021-04-22 Compact Laser Solutions Gmbh Device for adjusting an optical component
CN114745058A (zh) * 2022-03-02 2022-07-12 鹏城实验室 一种多元共形阵列的激光通信装置及通信方法

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3924937A (en) * 1974-01-30 1975-12-09 Jersey Nuclear Avco Isotopes Method and apparatus for sequentially combining pulsed beams of radiation
US4820899A (en) * 1987-03-03 1989-04-11 Nikon Corporation Laser beam working system
US5699589A (en) * 1996-05-03 1997-12-23 Ripley; William G. Laser cleaning and bleaching apparatus
US6183092B1 (en) * 1998-05-01 2001-02-06 Diane Troyer Laser projection apparatus with liquid-crystal light valves and scanning reading beam

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3924937A (en) * 1974-01-30 1975-12-09 Jersey Nuclear Avco Isotopes Method and apparatus for sequentially combining pulsed beams of radiation
US4820899A (en) * 1987-03-03 1989-04-11 Nikon Corporation Laser beam working system
US5699589A (en) * 1996-05-03 1997-12-23 Ripley; William G. Laser cleaning and bleaching apparatus
US6183092B1 (en) * 1998-05-01 2001-02-06 Diane Troyer Laser projection apparatus with liquid-crystal light valves and scanning reading beam

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1376191A1 (fr) * 2002-06-21 2004-01-02 Nikon Corporation Système d' actionnement d' un miroir deformable
JP2007529637A (ja) * 2004-02-27 2007-10-25 ザ プロクター アンド ギャンブル カンパニー 多重使用布地コンディショニング物品のための凹面組成物担体
JP4833193B2 (ja) * 2004-02-27 2011-12-07 ザ プロクター アンド ギャンブル カンパニー 多重使用布地コンディショニング物品のための凹面組成物担体
WO2006071943A1 (fr) * 2004-12-28 2006-07-06 Intel Corporation Pilotes de lasers a option de choix de plots integres permettant de selectionner des courants
EP2879387A1 (fr) * 2013-10-31 2015-06-03 Christie Digital Systems Canada, Inc. Système et appareil de distribution de lumière dynamique
US9473754B2 (en) 2013-10-31 2016-10-18 Christie Digital Systems Usa, Inc. Dynamic light distribution system and apparatus
US9435964B2 (en) 2014-02-26 2016-09-06 TeraDiode, Inc. Systems and methods for laser systems with variable beam parameter product
US9726834B2 (en) 2014-02-26 2017-08-08 TeraDiode, Inc. Systems and methods for laser systems with variable beam parameter product utilizing acousto-optic elements and variable refractive index components
US10261271B2 (en) 2014-02-26 2019-04-16 TeraDiode, Inc. Laser systems with variable beam parameter product utilizing uniaxial crystals or beam splitters
US10914902B2 (en) 2014-02-26 2021-02-09 TeraDiode, Inc. Methods for altering properties of a radiation beam
US11480846B2 (en) 2014-02-26 2022-10-25 TeraDiode, Inc. Systems and methods for laser systems with variable beam parameter product
WO2015200271A1 (fr) * 2014-06-25 2015-12-30 TeraDiode, Inc. Systèmes et procédés pour systèmes laser à produit de paramètres de faisceau variable
US20210119404A1 (en) * 2017-11-09 2021-04-22 Compact Laser Solutions Gmbh Device for adjusting an optical component
CN114745058A (zh) * 2022-03-02 2022-07-12 鹏城实验室 一种多元共形阵列的激光通信装置及通信方法

Similar Documents

Publication Publication Date Title
US6914916B2 (en) Tunable controlled laser array
US6754243B2 (en) Tunable distributed feedback laser
CN108983369B (zh) 用于在光子集成电路中的应用的mems倾斜反射镜
US6891676B2 (en) Tunable spectral filter
US5228103A (en) Monolithically integrated wavelength division multiplexing laser array
US6163643A (en) Micro-mechanical variable optical attenuator
KR100444176B1 (ko) 전기 신호에 의해 동작되는 광 편향기 및 이를 이용한파장 가변형 외부 공진기
EP2805389B1 (fr) Diode laser à cavité externe accordable en longueur d'onde ayant un réseau prismé pour tomographie par cohérence optique (oct)
US6618519B2 (en) Switch and variable optical attenuator for single or arrayed optical channels
US6879442B2 (en) Method and system for selecting an output of a VCSEL array
US6791694B2 (en) Tunable optical device using a scanning MEMS mirror
US20050074204A1 (en) Spectral plane method and apparatus for wavelength-selective optical switching
US6965710B2 (en) Optical switch and its production method, and optical path-switching apparatus comprising optical switch
KR101004175B1 (ko) 외부 공동 광학계를 위한 재귀 반사형 렌즈
KR20030064850A (ko) 미세-전자기계로 재구성 가능한 광학격자
US7142569B2 (en) Tunable laser source and wavelength selection method thereof
US20060280421A1 (en) Variable light attenuator
WO2003010568A1 (fr) Ensemble de lasers regules accordables
WO2020205673A1 (fr) Formation de faisceau de miroir sur puce
US6229934B1 (en) High-speed low-loss fiber-optic switches
US20030039275A1 (en) Method and system for selecting an output of a DBR array
US6865346B1 (en) Fiber optic transceiver
US6912335B2 (en) Optical switch with reduced beam divergence
EP1484625A1 (fr) Dispositif optique de couplage de la lumière d'un réseau de lasers dans une fibre optique
US20230384579A1 (en) Methods and systems of mechanical tuning multi channel optical components

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

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

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CO 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 UZ VN YU ZA ZW

AL Designated countries for regional patents

Kind code of ref document: A1

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 GQ GW ML MR NE SN TD TG

Kind code of ref document: A1

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

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

Ref country code: JP