EP0444959A2
Expired / Lapsed
EP
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Optical waveguide device
Assignee: Fujitsu Ltd
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Filing: 1991-03-01
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Granted: —
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Expires: 2011-03-01
Abstract
Abstract An optical waveguide device includes an optical waveguide (2, 2a, 2b) formed on a surface of a substrate (1) having an electrooptical effect, and a pair of electrodes (5, 6) formed on corresponding regions above the optical waveguide and receiving a driving electric signal thereacross. By applying the electric signal to the electrodes, an electric field is formed in a vicinity of the optical waveguide. By changing a distribution of the electric field in accordance with a change in a frequency of the electric signal, it is possible to suppress a DC drift of the device to effectively compensate a fluctuation in operational characteristics due to the DC drift, stress, or the like.
Inventors
- 👤 Minoru Seino
- 👤 Naoyuki Mekada
- 👤 Tadao Nakazawa
- 👤 Yoshinobu Kubota
- 👤 Masaharu Doi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 03:06
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/03; G02F1/035; G02F1/21; G02F1/225; G02F1/2255; G02F2201/00; G02F2201/06; G02F2201/066; G02F2203/00; G02F2203/21
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
81 words
An optical waveguide device comprising: an optical waveguide (2, 2a, 2b) formed on a surface of a substrate (1) having an electrooptical effect; and a pair of electrodes (5, 6) formed on corresponding regions above the optical waveguide and receiving a driving electric signal thereacross, wherein a distribution of electric field occuring in a vicinity of the optical waveguide by an application of the electric signal is greatly changed in accordance with a change in a frequency of the electric signal.
Claim 2
Dependent Claim
64 words
An optical waveguide device as set forth in claim 1, further comprising a third electrode (10, 10a, 10B) formed on a corresponding region above the substrate, the third electrode being disposed on the region spaced with a predetermined distance from the pair of electrodes formed on the corresponding regions above the optical waveguide and receiving a direct current voltage or a low frequency voltage.
Claim 3
Dependent Claim
25 words
An optical waveguide device as set forth in claim 2, further comprising a buffer layer (3) formed all over the substrate including the optical waveguide.
Claim 4
Dependent Claim
22 words
An optical waveguide device as set forth in claim 3, wherein the third electrode is comprised of a conductive layer (10, 10b).
Claim 5
Dependent Claim
21 words
An optical waveguide device as set forth in claim 3, wherein the third electrode is comprised of a semiconductive layer (10a).
Claim 6
Dependent Claim
52 words
An optical waveguide device as set forth in claim 5, further comprising a second semiconductive layer (4) formed between the buffer layer and the pair of electrodes and third electrode and all over the buffer layer, wherein the third electrode has a specific resistance different from that of the second semiconductive layer.
Claim 7
Dependent Claim
79 words
An optical waveguide device as set forth in claim 4, further comprising: a first semiconductive layer (4) formed between the buffer layer and the pair of electrodes and all over the buffer layer; and a second semiconductive layer (10a) formed between the first semiconductive layer and the third electrode, the second semiconductive layer having a broader width than that of the third electrode and being disposed on a region spaced with a predetermined distance from the pair of electrodes.
Claim 8
Dependent Claim
68 words
An optical waveguide device as set forth in claim 4, further comprising: a first semiconductive layer (4) formed all over the buffer layer; and a second semiconductive layer (9a, 9b, 9c) formed between the first semiconductive layer and the pair of electrodes and third electrode, the second semiconductive layer having a broader width than that of each electrode and being separated in corresponding regions thereof between each electrode.
Claim 9
Dependent Claim
98 words
An optical waveguide device as set forth in claim 1, further comprising: a buffer layer (3) formed all over the substrate including the optical waveguide; a semiconductive layer (4) formed between the buffer layer and the pair of electrodes and all over the buffer layer; and a third electrode (10) formed on the semiconductive layer, the third electrode being disposed on a region spaced from the pair of electrodes with a sufficient distance such that the presence thereof does not have a substantial influence on a characteristic impedance of the optical waveguide, and the third electrode being grounded.
Claim 10
Dependent Claim
97 words
An optical waveguide device as set forth in claim 1, further comprising: a buffer layer (3) formed all over the substrate including the optical waveguide; and a semiconductive layer (4a, 4b) formed between the buffer layer and the pair of electrodes, the semiconductive layer being separated in a corresponding region thereof between the pair of electrodes, each separated region having a broader width than that of the corresponding electrode, wherein, when a low frequency electric signal is applied to the pair of electrodes, the electric field is concentrated on the separated portion (P) of the semiconductive layer.
Claim 11
Dependent Claim
44 words
An optical waveguide device as set forth in claim 10, wherein the separated region (4a) of the semiconductive layer corresponding to an electrode for signal line (5) of the pair of electrodes is formed only in the vicinity of the electrode for signal line.
Claim 12
Dependent Claim
117 words
An optical waveguide device as set forth in claim 1, further comprising: a buffer layer (3) formed all over the substrate including the optical waveguide; and a semiconductive layer (4c) formed between the buffer layer and the pair of electrodes and all over the buffer layer, the semiconductive layer having a thinly formed portion (Q) in a corresponding region thereof between the pair of electrodes, wherein, when a low frequency electric signal is applied to the pair of electrodes, a greater part of a voltage drop caused by the application of the electric signal is applied to the thinly formed portion of the semiconductive layer and thus the electric field is concentrated on the thinly formed portion.
Claim 13
Dependent Claim
30 words
An optical waveguide device as set forth in claim 12, wherein the semiconductive layer including the thinly formed portion is formed only in the vicinity of the pair of electrodes.
Claim 14
Dependent Claim
91 words
An optical waveguide device as set forth in claim 1, further comprising: a buffer layer (3) formed all over the substrate including the optical waveguide; and a first semiconductive layer (4) formed all other the buffer layer; and a second semiconductive layer (9a) formed between the first semiconductive layer (4) and an electrode for signal line (5) of the pair of electrodes, the second semiconductive layer having a specific resistance different from that of the first semiconductive layer and having a broader width than that of the electrode for signal line.
Claim 15
Dependent Claim
97 words
An optical waveguide device as set forth in claim 1, further comprising: a buffer layer (3) formed all over the substrate including the optical waveguide; and a first semiconductive layer (4) formed all over the buffer layer; and a second semiconductive layer (9a, 9b) formed between the first semiconductive layer and the pair of electrodes, the second semiconductive layer being separated in a corresponding region thereof between the pair of electrodes and having a specific resistance different from that of the first semiconductive layer, each separated region having a broader width than that of the corresponding electrode.
Claim 16
Dependent Claim
36 words
An optical waveguide device as set forth in any one of claims 3 to 15, wherein the buffer layer is comprised of dielectric material and has a smaller refractive index than that of the optical waveguide.
Claim 17
Dependent Claim
19 words
An optical waveguide device as set forth in claim 16, wherein the dielectric material is comprised of silicon dioxide.
Claim 18
Dependent Claim
23 words
An optical waveguide device as set forth in any one of claims 5 to 15, wherein the semiconductive layer is comprised of silicon.
References Cited (Backward Citations)
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