EP0037263A1
Expired / Lapsed
EP
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Optical waveguide device
Assignee: Fujitsu Ltd
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Filing: 1981-03-27
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Granted: —
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Expires: 2001-03-27
Abstract
Abstract An optical waveguide device (140) is disclosed, which includes an optical waveguide member (11) for receiving a thin beam (Lin) of polarized light, modifying the beam, and emitting a differently polarized beam (Lout) from an output surface. The beam is modulated within the waveguide member (11) by the application of an electric field or a magnetic field. For a given supply voltage (V, 13), the greatest modulating effect is obtained with long and very thin waveguide members. In the device according to the invention, the top and bottom surfaces of the waveguide member (11) are coated with at least one phase-matching layer (141,141'). The thicknesses and refractive indices of the coatings are calculated so as to reduce substantially to zero the difference between the phase shifts experienced on reflection at each surface by P polarized and S polarized components of the light beam.
Inventors
- 👤 Masataka Shirasaki
- 👤 Takeshi Obokata
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 03:03
CPC Classifications
H; H04; H04B; H04B10/00; H04B10/25; G; G02; G02F; G02F1/00; G02F1/01; G02F1/011
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
136 words
An optical waveguide device comprising an optical waveguide member (11) whose thickness (d) is very much smaller than its length (1) along an optic axis, the waveguide member receiving a light beam (L. ) through an input surface, modifying the beam as it passes generally parallel to the optic axis, and emitting the modified light beam (L out ) from an output surface, the light beam having undergone a plurality of reflections from top and bottom waveguide surfaces of the waveguide member substantially parallel to the optic axis, characterized in that each of the top and bottom surfaces has at least one phase-matching layer (42,43) whose function is to decrease substantially an inherent difference (dΔ) between the phase shifts experienced on reflection at each surface by P polarized and S polarized components of the light beam.
Claim 2
Dependent Claim
136 words
An optical waveguide device comprising an optical waveguide member (11) whose thickness (d) is very much smaller than its length (1) along an optic axis, the waveguide member receiving a light beam (L. ) through an input surface, modifying the beam as it passes generally parallel to the optic axis, and emitting the modified light beam (L out ) from an output surface, the light beam having undergone a plurality of reflections from top and bottom waveguide surfaces of the waveguide member substantially parallel to the optic axis, characterized in that each of the top and bottom surfaces has at least one phase-matching layer (42,43) whose function is to decrease substantially an inherent difference (dΔ) between the phase shifts experienced on reflection at each surface by P polarized and S polarized components of the light beam.
Claim 3
Dependent Claim
110 words
A device as set forth in claim 1, wherein one phase-matching layer (132, 132', fig. 13) is provided on each of the top and bottom surfaces of the optical waveguide member, and wherein a relative refractive index n21 s (defined by the ratio of the refractive index nl , for the S-polarized light component, of the optical waveguide member with respect to a refractive index n2 of the phase-matching layer, that is is larger than a relative refractive index n21 (defined by the ratio of the refractive index n1 p , for the P-polarized light component, of the optical waveguide member with respect to the refractive index n2, that is
Claim 4
Dependent Claim
73 words
A device as set forth in claim 1, wherein first and second phase-matching layers (42, 43, fig. 5) are provided on each of the top and bottom surfaces of the optical waveguide member, the first and second layers, counted from the optical waveguide member, having refractive indices nl and n2, respectively, which satisfy the conditions n2 < n0 < nl, where the symbol n0 denotes the refractive index of the optical waveguide member.
Claim 5
Dependent Claim
80 words
A device as set forth in claim 1, wherein first, second and third phase-matching layers'(102, 103, 104, Fig.10) are mounted on each of the top and bottom surfaces of the optical waveguide member, the first, second and third layers, counted from the optical waveguide member, having refractive and indices nl,h2 / n3, respectively, which satisfy the conditions nl< n0 < n2 and n3 < n0 < n2, where the symbol nO denotes the refractive index of the optical waveguide member.
Claim 6
Dependent Claim
31 words
A device as set forth in claim 2, 3 or 4, wherein the optical waveguide member is made of a glass, or is an electro-optic crystal, or is a magneto-optic crystal.
Claim 7
Independent Claim
33 words
A device as set forth in any of claims 1 to 4, wherein the optical waveguide member is an electro-optic crystal to which an external voltage is applied via a pair of electrodes.
Claim 8
Dependent Claim
24 words
A device as set forth in claim 6, wherein the first layer acts as one of the electrodes, and the first layer is conductive.
Claim 9
Dependent Claim
48 words
A device as set forth in claim 6, wherein the second or third layer acts as one of the electrodes, and wherein the second or the third layer is conductive and electrically connected to the optical waveguide member via an electrically conductive or low resistance layer or layers.
Claim 10
Dependent Claim
40 words
A device as set forth in claim 6, wherein the electro-optic crystal is made of Bi 12 SiO 20 , the first layer and the third layer are made of SiO 2 and the second layer is made of SiH.
Claim 11
Dependent Claim
48 words
A device as set forth in claim 7, wherein the electro-optic crystal is made of Bi 12 SiO 20 , the first layer is made of In 2 0 3 , the second layer is made of SiH and the third layer is made of SiO 2 .
Claim 12
Independent Claim
41 words
A device as set forth in any one of claims 1 to 4, wherein the optical waveguide member is a magneto-optic crystal, the first and the third layers are made of Si0 2 and the second layer is made of SiH.
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