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US4887877A
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Optical devices and optical integrated circuits
Assignee: Hitachi Ltd
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Filing: 1988-12-15
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Granted: 1989-12-19
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Expires: 2008-12-15
Abstract
Abstract An optical device and an optical integrated circuit which incorporate an optical switch and have a novel function. Light sources are respectively coupled to two input ends of an X-type 2×2 optical switch, and light receivers are respectively coupled to two output ends of the optical switch, thereby obtaining an optical device which is capable of performing both AND and OR logics. A light source is coupled to one input end of an optical switch, and a light receiver is provided at one output end from which the light emitted from the light source emerges when no electric power is supplied to the optical switch, whereby it is possible to construct a system in which, even when one terminal has a power failure, there is no hindrance to other terminals. If an optical switch is arranged such as to use driving electric power as a modulating signal, the optical switch can serve as a modulator in which the output from one output end can be employed to monitor a modulated optical signal. In addition, if the optical switch is formed into, e.g., a carrier injection type optical switch using a semiconductor, the above-described devices can be fabricated as integrated circuit.
Inventors
- 👤 Hiroaki Inoue
- 👤 Shinji Sakano
- 👤 Hitoshi Nakamura
- 👤 Toshio Katsuyama
- 👤 Hiroyoshi Matsumura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:13
CPC Classifications
G; G02; G02F; G02F3/00; G02F1/00; G02F1/29; G02F1/31; G02F1/313; G02F1/3137; G02F1/3138
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
142 words
An optical logic device comprising an X-type 2×2 reflecting optical switch having two input ends and two output ends; two light-emitting elements operatively coupled to respective said input ends of said optical switch; and means for selectively allowing light entering at least one of said input ends from respective light-emitting elements to emerge from at least one of said output ends in response to a signal applied to said optical switch, wherein optical guides fabricated on a semiconductor substrate couple said light-emitting elements to said input ends and form a region of intersection having a variable refractive index with said optical switch, whereby said means varies the refractive index of at least a part of said region in response to the signal applied to said optical switch, and said light-emitting elements and said optical switch are monolithically integrated on the semiconductor substrate.
Claim 2
Dependent Claim
142 words
An optical logic device comprising an X-type 2×2 reflecting optical switch having two input ends and two output ends; two light-emitting elements operatively coupled to respective said input ends of said optical switch; and means for selectively allowing light entering at least one of said input ends from respective light-emitting elements to emerge from at least one of said output ends in response to a signal applied to said optical switch, wherein optical guides fabricated on a semiconductor substrate couple said light-emitting elements to said input ends and form a region of intersection having a variable refractive index with said optical switch, whereby said means varies the refractive index of at least a part of said region in response to the signal applied to said optical switch, and said light-emitting elements and said optical switch are monolithically integrated on the semiconductor substrate.
Claim 3
Dependent Claim
42 words
An optical logic device according to claim 1, wherein the signal applied to said optical switch and light from one of said light-emitting elements allows the device to make an AND operation when the other of said light-emitting elements emits no light.
Claim 4
Dependent Claim
32 words
An optical logic device according to claim 1, wherein the signal applied to said optical switch and light from both of said light-emitting elements allows the device to make an OR operation.
Claim 5
Dependent Claim
16 words
An optical logic device according to claim 1, wherein said light-emitting elements are distributed feedback lasers.
Claim 6
Dependent Claim
30 words
An optical logic device according to claim 4, wherein said lasers and said optical switch are monolithically integrated on a semiconductor substrate on which a diffraction grating has been fabricated.
Claim 7
Dependent Claim
51 words
An optical logic device according to claim 5, wherein optical guides are fabricated on said substrate to coupled said lasers to said input ends of said optical switch, whereby said optical guides are defined by an InGaAsP guide layer and an InP cap layer and said substrate is in InP substrate.
Claim 8
Dependent Claim
39 words
An optical logic device according to claim 1, wherein optical guides fabricated on a semiconductor substrate couple said light-emitting elements to said input ends and form a region of intersection of at least about 7° with said optical switch.
Claim 9
Dependent Claim
17 words
An optical logic device according to claim 1, wherein said optical switch has a LiNbO 3 substrate.
Claim 10
Dependent Claim
16 words
An optical logic device according to claim 1, wherein said light-emitting elements are InP semiconductor lasers.
Claim 11
Dependent Claim
37 words
An optical logic device according to claim 1, wherein a light-receiving element is operatively located at one of said output ends and receives light from said light-emitting elements when no signal is applied to said optical switch.
Claim 12
Dependent Claim
98 words
An optical integrated device comprising: a compound semiconductor substrate; means for emitting light constituted by a compound semiconductor monolithically integrated on said substrate; an optical modulator constituted of a compound semiconductor in a crystal system the same as that of said substrate and having a variable refractive index; an optical guide fabricated on said substrate so as to have a region of intersection with said optical modulator; and means for switching light emitted from said light-emitting means at said region of intersection by varying the refractive index thereat by means of a signal applied to said optical modulator.
Claim 13
Dependent Claim
98 words
An optical integrated device comprising: a compound semiconductor substrate; means for emitting light constituted by a compound semiconductor monolithically integrated on said substrate; an optical modulator constituted of a compound semiconductor in a crystal system the same as that of said substrate and having a variable refractive index; an optical guide fabricated on said substrate so as to have a region of intersection with said optical modulator; and means for switching light emitted from said light-emitting means at said region of intersection by varying the refractive index thereat by means of a signal applied to said optical modulator.
Claim 14
Dependent Claim
27 words
An optical integrated device according to claim 11, wherein said optical modulator has a forbidden band of different magnitude from a forbidden band of said light-emitting means.
Claim 15
Dependent Claim
30 words
An optical integrated device according to claim 11, wherein said optical guide is a compound semiconductor in a crystal system the same as that of said optical modulator and substrate.
Claim 16
Dependent Claim
32 words
An optical integrated device according to claim 11, wherein said optical modulator has two output ends, and a light-receiving element is monolithically integrated on said substrate at one of said output ends.
Claim 17
Dependent Claim
30 words
An optical integrated device according to claim 14, wherein said light-receiving element is a compound semiconductor in a crystal system the same as that of said optical modulator and substrate.
Claim 18
Dependent Claim
26 words
An optical integrated device according to claim 14, wherein said optical modulator has two input ends, said light-emitting means being operatively coupled to said input ends.
Claim 19
Dependent Claim
21 words
An optical integrated device according to claim 14, wherein an optical amplifier is operatively located at one of said output ends.
Claim 20
Dependent Claim
30 words
An optical integrated device according to claim 14, wherein said light-receiving element is operative to receive light from said light-emitting element when no signal is applied to said optical modulator.
Claim 21
Dependent Claim
25 words
An optical integrated device according to claim 14, wherein said substrate is provided with a diffraction grating except in the region of said light-receiving element.
Claim 22
Dependent Claim
17 words
An optical integrated device according to claim 11, wherein said optical modulator includes a transposition optical switch.
Claim 23
Dependent Claim
19 words
An optical integrated device according to claim 11, wherein said light-emitting means is at least one distributed feedback laser.
Claim 24
Dependent Claim
96 words
An optical logic device performing two variable-two value logic comprising: a plurality of input ends for taking in light emitted from a plurality of light emitting elements; a plurality of output ends for taking out the light; a plurality of optical guides for connecting the input ends with the output ends; and an intersection region of the optical guides for switching the taken in light in accordance with an applied signal, wherein the two variable-two value logic comprises a logic signal of the applied signal and a logic signal of one of the light emitting elements.
Claim 25
Dependent Claim
96 words
An optical logic device performing two variable-two value logic comprising: a plurality of input ends for taking in light emitted from a plurality of light emitting elements; a plurality of output ends for taking out the light; a plurality of optical guides for connecting the input ends with the output ends; and an intersection region of the optical guides for switching the taken in light in accordance with an applied signal, wherein the two variable-two value logic comprises a logic signal of the applied signal and a logic signal of one of the light emitting elements.
Claim 26
Dependent Claim
18 words
An optical logic device according to claim 22, wherein the intersection region includes a reflection type optical switch.
Claim 27
Dependent Claim
17 words
An optical logic device according to claim 22, wherein the light emitting elements are distributed feedback lasers.
Claim 28
Dependent Claim
30 words
An optical logic device according to claim 24, wherein the intersection region includes a reflection type optical switch and has a refractive index variable in response to the applied signal.
Claim 29
Dependent Claim
134 words
An optical logic device comprising: first and second input ends for taking in light emitted from first and second light emitting elements, respectively; first and second output ends for taking out the emitted light; a plurality of optical guides for connecting the input ends with the output ends; and an intersection region of the optical guides for switching the light in accordance with an applied signal, wherein an AND logic output defined by logic signals of the applied signal and the first light emitting element is obtained from the first output end when the second light emitting element is OFF, and a OR logic output defined by logic signals of the first light emitting element and the applied signal is obtained from the second output end when the second light emitting element is ON.
Claim 30
Dependent Claim
134 words
An optical logic device comprising: first and second input ends for taking in light emitted from first and second light emitting elements, respectively; first and second output ends for taking out the emitted light; a plurality of optical guides for connecting the input ends with the output ends; and an intersection region of the optical guides for switching the light in accordance with an applied signal, wherein an AND logic output defined by logic signals of the applied signal and the first light emitting element is obtained from the first output end when the second light emitting element is OFF, and a OR logic output defined by logic signals of the first light emitting element and the applied signal is obtained from the second output end when the second light emitting element is ON.
Claim 31
Dependent Claim
18 words
An optical logic device according to claim 26, wherein the intersection region includes a reflection type optical switch.
Claim 32
Dependent Claim
17 words
An optical logic device according to claim 26, wherein the light emitting elements are distributed feedback lasers.
Claim 33
Dependent Claim
30 words
An optical logic device according to claim 28, wherein the intersection region includes a reflection type optical switch and has a refractive index variable in response to the applied signal.
References Cited (Backward Citations)
US4679893A
Cited
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-12-18 | 1993-06-19 | 1993-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-18 | 1997-06-19 | 1997-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-18 | 2001-06-19 | 2001-12-19 | $7700.00 | Window Closed / Lapsed |