EP0000810A1 - Méthode et appareil pour former des réseaux de diffraction focalisateurs pour l'optique intégrée - Google Patents

Méthode et appareil pour former des réseaux de diffraction focalisateurs pour l'optique intégrée Download PDF

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Publication number
EP0000810A1
EP0000810A1 EP7878300156A EP78300156A EP0000810A1 EP 0000810 A1 EP0000810 A1 EP 0000810A1 EP 7878300156 A EP7878300156 A EP 7878300156A EP 78300156 A EP78300156 A EP 78300156A EP 0000810 A1 EP0000810 A1 EP 0000810A1
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EP
European Patent Office
Prior art keywords
beams
plane
photosensitive material
lines
focal
Prior art date
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Granted
Application number
EP7878300156A
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German (de)
English (en)
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EP0000810B1 (fr
Inventor
Ping King Tien
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AT&T Corp
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Western Electric Co Inc
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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/32—Holograms used as optical elements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
    • H01S3/06—Construction or shape of active medium
    • H01S3/063—Waveguide lasers, i.e. whereby the dimensions of the waveguide are of the order of the light wavelength
    • H01S3/0632—Thin film lasers in which light propagates in the plane of the thin film
    • H01S3/0635—Thin film lasers in which light propagates in the plane of the thin film provided with a periodic structure, e.g. using distributed feed-back, grating couplers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S359/00—Optical: systems and elements
    • Y10S359/90—Methods

Definitions

  • the invention relates to methods and apparatus for producing holographic diffraction gratings and the like.
  • Gratings that have substantially equal spacing between their lines are referred to as being unchirped. They are especially useful for focusing as well as diffracting light in integrated optical devices.
  • Gratings have been incorporated in integrated optics devices for several purposes, including the fabrication of distributed feedback lasers, lightwave couplers, and band-rejection filters.
  • Integrated- optics gratings known to the prior art were composed of straight lines, and therefore could not focus the light being processed.
  • Gratings that combine focusing and diffraction were known to be desirable, but the prior art was unable to produce them.
  • U.S. Patent 3,578,845 discloses a method and apparatus for producing curved-line holographic gratings that have unequally spaced, or chirped, lines. This patent teaches the production of gratings that focus light that propagates into and out of the plane of the grating. It does not teach the relative orientation of laser beams and focal lines that are required in order to produce curveo-line gratings that will function in integrated optics devices.
  • a method of forming a holographic. diffraction grating having lines of substantially equal spacing comprising generating first and second beams of coherent optical radiation, causing the first and second beams to interfere with each other on a planar piece of photosensitive material to form an interference pattern in the photosensitive material, and processing to form the interference pattern, characterised in that the first and second beams are coplanar in a first plane, and in that the planar piece of photosensitive material lies in a second plane oriented substantially perpendicular to the first plane.
  • an apparatus for forming an optical interference pattern with curved equally spaced .lines in a planar photosensitive material said apparatus connirising means for generating first and second beams of coherent optical radiation, each beam being focussed to a respective focal line (ff,gg) at a predetermined position, characterised in that the focal lines are coplanar and define a first plane (Y, X), and in that the apparatus further comprises means for supporting a planar piece of photoseusitive material (5) oriented in a second plane (Z, X) substantially perpendicular to the first plane.
  • the present invention relates to a method and apparatus for producing unchirped, curved-line, holographic diffraction gratings in a thin film, which gratings will focus as well as diffract light that is confined to the film in which the grating is formed.
  • the film containing the light is called optical waveguide and the waveguide with a grating in it is called a corrugated waveguide.
  • the gratings are made by forming an interference pattern in a photosensitive material, photographically processing the interference pattern so formed such as by developing and fixing, and then using the fixed pattern as a mask for ion or chemical etching processes of conventional type to form corrugated waveguides.
  • two cylindrically focused beams of coherent optical radiation are provided for writing holographic diffraction gratings.
  • the focal lines of the beams are oriented in a predetermined manner with respect to each other and with respect to the grating being written.
  • the focal lines of the two beams are coplanar and are oriented so that the plane which contains the focal lines also contains the axis of the grating, thereby providing uniform spacing between the grating lines.
  • FIG. 1A The basic optical system used to form the embodiment gratings is shown in FIG. 1A. It involves two oblique coherent light beams 1 and 2, generated by conventional means not shown, focused by two cylindrical lenses 3 and 4, respectively.
  • a curved-line grating is formed by recording the interference pattern of the two light beams on a photoresist plate 5.
  • lines f-f and g-g the focal lines of beams 1 and 2 respectively, are horizontal and are not necessarily parallel to the plate. This is in contrast with the prior art apparatus of U.S. Patent 3,578,845 referred to above in which focal lines would be oriented in the vertical direction and parallel to the photosensitive plate (see FIGS. 4 and 6 of Patent 3,578,845) The relative orientation of these focal lines and their relationship with the plate 5 determine the form of grating that will be formed and are the key to the invention.
  • the particular value of z and the choice of a horizontal plane are, of course, arbitrarily chosen in order to make the illustration more comprehensible.
  • the essential point is that the two incident beams are coplanar, i.e. they are centered about the same plane (the "beam plane"), and that plane is substantially perpendicular to the plane of the photosensitive material. Since the focal lines f-f and g-g and lenses 3 and 4 are centered in their respective beams, they lie in the "beam plane” also. The above remarks hold true even if one or more of the beams is collimated and the corresponding focal line is theoretically at infinity. If one focal line lies at a great distance from the photosensitive plate, the beam plane is still unambiguously defined by the centers of the beams, the centers of the lenses and the other focal line.
  • each fringe and the spacing between fringes on the x axis must be specified.
  • the inter-fringe spacing is specified by the Bragg-reflection condition: where d is the inter-fringe spacing, m is an integer specifying the diffraction order, and A is the wavelength of the light beams 1 and 2.
  • the curvature of the fringe may also be expressed in terms of the beams 1 and 2 used to write the grating.
  • FIG. 1B which shows a view looking down on the x,'y plane of FIG. 1A, ac is the distance along the direction of propagation of beam 1 from focal line f-f to the x axis, and bc is the corresponding distance for beam 2.
  • the curvature of the fringes may be expressed in terms of the curvatures of the two beams.
  • x o at G
  • ⁇ the distance F-G
  • a the angle between the direction of propagation of beam 1 and the x-axis. Equations I through 4 permit the design of gratings to accomplish the various tasks disclosed above.
  • FIG. 1C shows a plan view looking down on the x, y plane of the apparatus shown in FIG. lA, further including the source of beams 1 and 2.
  • the particular case where the beams intersect the x-axis at an angle a of 45 degrees is shown.
  • Other configurations of beam angle and therefore of mirror position will be required to form gratings for various purposes and may be readily calculated by those skilled in the art from the information disclosed in this application.
  • laser 9 generates a parallel beam of coherent optical radiation. It may be desired to employ a mask 10 to define the shape of the beam envelope (rectangular, square, et cetera).
  • the beam from laser 9 is split by beam splitter 8, forming beams 1 and 2. These two beams are reflected by mirrors 6 and 7 into lenses 3 and 4 respectively.
  • the position of all these elements will, of course, be adjusted to give the angles between beams 1 and 2 and plate 5 and the positions of focal lines f-f and g-g that are required by Equations 1 to 4 to provide the grating parameters that are desired.
  • FIG. 2A a grating is used to reflect and focus light emitting from a point source G in a waveguide back to that same point.
  • FIG. 2B illustrates the optics used, looking down on the x-y plane.
  • the first figure shows the grating in operation, and the next figure shows the parameters used to write the grating.
  • Beam 1 focused at infinity, crosses the x axis at an angle ⁇ .
  • Beam 2 is focused at line g-g, which crosses the x axis at point G, the same point as the focus, at an angle ⁇ B .
  • line g-g is not at right angles to the direction of propagation of beam 2, which is 180 - a.
  • the lines 1 and 2 illustrate the center lines of the beams 1 and 2, respectively.
  • the beams are wide and they overlap one another as they are projected to the plate forming an interference pattern.
  • a plane parallel beam in a waveguide is focused to a point, at G in the same waveguide (FIG. 2C).
  • FIG. 2D we see that beam 1 (plane-parallel) is oriented as before, and that g-g is at right angles to the x axis, passing through point G.
  • Beam 2 has the same direction of propagation as in FIG. 2B.
  • both beams 1 and 2 are focused at finite distances, both focal lines being perpendicular to the x axis as shown in FIG. 2H.
  • Line f-f intersects the axis at point F, the image point, and line g-g intersects the axis at point G, the object point.
  • embodiment gratings may be used to form resonators in diode-lasers.
  • N the mode index of the waveguide
  • Equation 5 the curvatures of the incident and reflected waves
  • FIG. 2K shows another grating-resonator designed for a distributed feedback laser.
  • Two cylindrically focused beams are used, as shown in FIG. 2L.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Optics & Photonics (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • General Physics & Mathematics (AREA)
  • Diffracting Gratings Or Hologram Optical Elements (AREA)
  • Optical Integrated Circuits (AREA)
  • Holo Graphy (AREA)
EP78300156A 1977-07-14 1978-07-17 Méthode et appareil pour former des réseaux de diffraction focalisateurs pour l'optique intégrée Expired EP0000810B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US05/815,721 US4140362A (en) 1977-07-14 1977-07-14 Forming focusing diffraction gratings for integrated optics
US815721 1977-07-14

Publications (2)

Publication Number Publication Date
EP0000810A1 true EP0000810A1 (fr) 1979-02-21
EP0000810B1 EP0000810B1 (fr) 1981-10-07

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EP78300156A Expired EP0000810B1 (fr) 1977-07-14 1978-07-17 Méthode et appareil pour former des réseaux de diffraction focalisateurs pour l'optique intégrée

Country Status (5)

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US (1) US4140362A (fr)
EP (1) EP0000810B1 (fr)
JP (1) JPS6048003B2 (fr)
CA (1) CA1102593A (fr)
DE (1) DE2861133D1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10156524B2 (en) 2012-12-04 2018-12-18 Hoffmann-La-Roche Inc. Device for use in the detection of binding affinities

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US4392709A (en) * 1980-10-29 1983-07-12 The United States Of America As Represented By The Secretary Of The Air Force Method of manufacturing holographic elements for fiber and integrated optic systems
US4387955A (en) * 1981-02-03 1983-06-14 The United States Of America As Represented By The Secretary Of The Air Force Holographic reflective grating multiplexer/demultiplexer
US4660934A (en) * 1984-03-21 1987-04-28 Kokusai Denshin Denwa Kabushiki Kaisha Method for manufacturing diffraction grating
US4578804A (en) * 1984-05-30 1986-03-25 The United States Of America As Represented By The Secretary Of The Navy Polynomial grating
JPS61180209A (ja) * 1985-02-06 1986-08-12 Matsushita Electric Ind Co Ltd 光分波器
JPS61182003A (ja) * 1985-02-07 1986-08-14 Matsushita Electric Ind Co Ltd 光分波器
JPS6219511U (fr) * 1985-07-20 1987-02-05
US4743083A (en) * 1985-12-30 1988-05-10 Schimpe Robert M Cylindrical diffraction grating couplers and distributed feedback resonators for guided wave devices
US4834474A (en) * 1987-05-01 1989-05-30 The University Of Rochester Optical systems using volume holographic elements to provide arbitrary space-time characteristics, including frequency-and/or spatially-dependent delay lines, chirped pulse compressors, pulse hirpers, pulse shapers, and laser resonators
US5013133A (en) 1988-10-31 1991-05-07 The University Of Rochester Diffractive optical imaging lens systems
US5338924A (en) * 1992-08-11 1994-08-16 Lasa Industries, Inc. Apparatus and method for automatic focusing of light using a fringe plate
US5357591A (en) * 1993-04-06 1994-10-18 Yuan Jiang Cylindrical-wave controlling, generating and guiding devices
AU761179B2 (en) * 1998-10-30 2003-05-29 Corning Incorporated Wavelength tuning of photo-induced gratings
WO2001038884A1 (fr) * 1999-11-22 2001-05-31 California Institute Of Technology Capteur de particules microphotoniques
US7773842B2 (en) * 2001-08-27 2010-08-10 Greiner Christoph M Amplitude and phase control in distributed optical structures
US7194164B2 (en) * 2000-03-16 2007-03-20 Lightsmyth Technologies Inc Distributed optical structures with improved diffraction efficiency and/or improved optical coupling
US6965464B2 (en) * 2000-03-16 2005-11-15 Lightsmyth Technologies Inc Optical processor
USRE41570E1 (en) 2000-03-16 2010-08-24 Greiner Christoph M Distributed optical structures in a planar waveguide coupling in-plane and out-of-plane optical signals
US7519248B2 (en) * 2000-03-16 2009-04-14 Lightsmyth Technologies Inc Transmission gratings designed by computed interference between simulated optical signals and fabricated by reduction lithography
USRE42206E1 (en) 2000-03-16 2011-03-08 Steyphi Services De Llc Multiple wavelength optical source
US6987911B2 (en) * 2000-03-16 2006-01-17 Lightsmyth Technologies, Inc. Multimode planar waveguide spectral filter
USRE42407E1 (en) 2000-03-16 2011-05-31 Steyphi Services De Llc Distributed optical structures with improved diffraction efficiency and/or improved optical coupling
US6879441B1 (en) 2000-03-16 2005-04-12 Thomas Mossberg Holographic spectral filter
US6884961B1 (en) 2000-08-24 2005-04-26 Uc Laser Ltd. Intravolume diffractive optical elements
WO2004057376A2 (fr) 2002-12-17 2004-07-08 Lightsmyth Technologies Incorporated Dispositif de multiplexage optique
US7260290B1 (en) 2003-12-24 2007-08-21 Lightsmyth Technologies Inc Distributed optical structures exhibiting reduced optical loss
US7181103B1 (en) 2004-02-20 2007-02-20 Lightsmyth Technologies Inc Optical interconnect structures incorporating sets of diffractive elements
US7359597B1 (en) 2004-08-23 2008-04-15 Lightsmyth Technologies Inc Birefringence control in planar optical waveguides
US7120334B1 (en) 2004-08-25 2006-10-10 Lightsmyth Technologies Inc Optical resonator formed in a planar optical waveguide with distributed optical structures
US7330614B1 (en) 2004-12-10 2008-02-12 Lightsmyth Technologies Inc. Integrated optical spectrometer incorporating sets of diffractive elements
US7327908B1 (en) 2005-03-07 2008-02-05 Lightsmyth Technologies Inc. Integrated optical sensor incorporating sets of diffractive elements
US7349599B1 (en) 2005-03-14 2008-03-25 Lightsmyth Technologies Inc Etched surface gratings fabricated using computed interference between simulated optical signals and reduction lithography
US7643400B1 (en) 2005-03-24 2010-01-05 Lightsmyth Technologies Inc Optical encoding of data with distributed diffractive structures
US7190856B1 (en) 2005-03-28 2007-03-13 Lightsmyth Technologies Inc Reconfigurable optical add-drop multiplexer incorporating sets of diffractive elements
US8068709B2 (en) * 2005-09-12 2011-11-29 Lightsmyth Technologies Inc. Transmission gratings designed by computed interference between simulated optical signals and fabricated by reduction lithography
CN101738664B (zh) * 2009-12-17 2011-08-17 上海理工大学 在平面光栅制作过程中精确控制光栅常数的方法
CN101866141B (zh) * 2010-05-25 2012-02-22 上海理工大学 大折射率调制度的斜条纹全息波导器件制作方法

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US3864130A (en) * 1971-03-02 1975-02-04 Bayer Ag Integrated optical circuits
US3991386A (en) * 1975-09-25 1976-11-09 Bell Telephone Laboratories, Incorporated Active optical devices with spatially modulated populations of F-centers

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Publication number Priority date Publication date Assignee Title
US10156524B2 (en) 2012-12-04 2018-12-18 Hoffmann-La-Roche Inc. Device for use in the detection of binding affinities

Also Published As

Publication number Publication date
CA1102593A (fr) 1981-06-09
JPS5434846A (en) 1979-03-14
JPS6048003B2 (ja) 1985-10-24
EP0000810B1 (fr) 1981-10-07
DE2861133D1 (en) 1981-12-17
US4140362A (en) 1979-02-20

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