EP0591042A1
Expired / Lapsed
EP
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Arrayed-wave guide grating multi/demultiplexer with loop-back optical paths
Assignee: NTT Inc
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Filing: 1993-09-28
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Granted: —
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Expires: 2013-09-28
Abstract
Abstract An optical device is presented which is useful for optical signal transmission and switching systems by multiplexing and demultiplexing optical signals in looped optical paths, consisting of a plurality of individual loop-back optical paths. The device is essentially a multi/demultiplexer having an arrayed waveguide grating disposed between a plurality of input sections and output sections which are joined by the plurality of individual loop-back optical paths. Because the modulated signals are looped back into the same optical paths using the same devices, problems of mismatching performance introduced by using different optical devices are avoided. The device processes individual optical signals of different wavelengths, minimizes splitting losses, and reduces noise components by producing narrow bandpass signals of high signal to noise ratio. Optical signal splitting and insertion, delay line memory and delay equalization circuits can all be handled by the same circuit configuration. The device is simple in construction, reliable in performance and economical in production.
Inventors
- 👤 Yoshiaki Tachikawa
- 👤 Masao Kawachi
- 👤 Hiroshi Takahashi
- 👤 Kyo Inoue
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 16:34
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/10; G02B6/12; G02B6/12007; G02B6/12009; G02B6/12014; G02B6/12016; G02B6/12019; G02B6/12021; G02B6/24; G02B6/26; G02B6/27; G02B6/2753; G02B6/278; G02B6/28; G02B6/2804; G02B6/2861; G02B6/293; G02B6/29346; G02B6/29361; G02B6/29379; G02B6/2938; G02B6/29395; G02B6/42; G02B6/4201; G02B6/4204; G02B6/4215; H; H01; H01S; H01S5/00; H01S5/02; H01S5/026; H01S5/0268; H01S5/10; H01S5/1071; H04; H04B; H04B2210/00; H04B2210/25; H04B2210/258
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
115 words
In an optical multi/demultiplexer device of an arrayed waveguide grating type for generating optical information from optical signals inputted into said device, said device comprising: (a) a plurality of input sections (43) for receiving optical signals consisting of a plurality of wavelengths, (b) a plurality of output sections (47) for outputting optical information; said optical multi/demultiplexer device characterized by having (c) a plurality of loop-back optical paths means (51) disposed between said plurality of input sections (43) and said plurality of output sections (47) for generating looping optical signals from said output section (47), and inputting said looping optical signals into corresponding sections of said input section (43) so as to generate output optical information.
Claim 2
Dependent Claim
27 words
An optical device as claimed in claim 1, wherein each of said plurality of loop-back optical paths means (51) is provided with a signal processor means (52).
Claim 3
Dependent Claim
32 words
An optical device as claimed in claim 1, 2 or 3 wherein a slab waveguide (44) is disposed between said plurality of input sections (43) and said plurality of output sections (47).
Claim 4
Dependent Claim
51 words
An optical device as claimed in claim 1, 2 or 3, wherein said looping optical signals include a pilot optical signal which is not looped back into said loop-back optical paths means (51), and is inputted into said multi/demultiplexer having arrayed grating (41) and is outputted from said output section (47).
Claim 5
Dependent Claim
48 words
An optical device as claimed in claim 1, 2 or 3, wherein a length of each of said plurality of loop-back optical paths means (51) is proportional to the wavelength of an optical signal being propagated in individual one of said plurality of loop-back optical paths means (51).
Claim 6
Dependent Claim
49 words
An optical device as claimed in claim 1, 2 or 3, wherein a length of each of said plurality of loop-back optical paths means (51) is inversely proportional to the wavelength of an optical signal being propagated in individual one of said plurality of loop-back optical paths means (51).
Claim 7
Dependent Claim
50 words
An optical device as claimed in claim 1, 2 or 3, wherein at least one input section of said plurality of input sections (43) is provided with a light source selected from a group consisting of a wavelength-tunable light source (81), a multi-wavelength light source and a fixed-wavelength light source.
Claim 8
Dependent Claim
30 words
An optical device as claimed in claim 1, 2 or 3, wherein at least one output section of said plurality of output sections (47) is provided with an photodetector means.
Claim 9
Dependent Claim
32 words
An optical device as claimed in claim 7, wherein an optical modulator (82) is provided between each input section of said plurality of input sections (43) and said wavelength-tunable light source (81).
Claim 10
Dependent Claim
32 words
An optical device as claimed in claim 7, wherein a polarization compensator (83) is provided between one input section of said plurality of input sections (43) and said wavelength-tunable light source (81).
Claim 11
Dependent Claim
23 words
An optical device as claimed in claim 1, wherein said optical device (41) and said loop-back optical paths means (51) are fabricated integrally.
Claim 12
Dependent Claim
29 words
An optical device as claimed in claim 1, wherein said optical device (41) and said loop-back optical paths means (71) are fabricated integrally on a common substrate base (73).
Claim 13
Dependent Claim
42 words
An optical device as claimed in claim 11 or 12, wherein each of said plurality of loop-back optical paths means (71) is provided with signal processing means (72) for processing an optical signal being propagated in said loop-back optical paths means (71).
Claim 14
Dependent Claim
47 words
An optical device as claimed in claim 13, wherein at least one of said signal processing means (72) is selected from a group consisting of an optical amplifier (95), an optical switch means (96), an optical filter means, photodetector and light source means, and optical coupler means.
Claim 15
Dependent Claim
43 words
An optical device as claimed in claim 11 or 12, wherein a length of each of said loop-back optical paths means (97) is proportional to the wavelength of an optical signal being propagated in respective one of said loop-back optical paths means (97).
Claim 16
Dependent Claim
43 words
An optical device as claimed in claim 11 or 12, a length of each of said loop-back optical paths means (97) is inversely proportional to the wavelength of an optical signal being propagated in respective one of said loop-back optical paths means (97).
Claim 17
Dependent Claim
49 words
An optical device as claimed in claim 11 or 12, wherein at least one input section of said plurality of input sections (43) is provided with an light source selected from a group consisting of a wavelength-tunable light source (81), a multi-wavelength light source and a fixed-wavelength light source.
Claim 18
Dependent Claim
32 words
An optical device as claimed in claim 17, wherein an optical modulator (82) is provided between one input section of said plurality of input sections (43) and said wavelength-tunable light source (81).
Claim 19
Dependent Claim
44 words
An optical device as claimed in claim 2, wherein at least one of said signal processing means (52) is selected from a group consisting of an optical switch means (58), an optical merging/splitting circuit means, optical filter means (65) and an optical coupler means.
Claim 20
Dependent Claim
49 words
An optical device as claimed in claim 19, said optical switch means (58) is an optical matrix switch (122) disposed so as to straddle across a plurality of said plurality of loop-back optical paths means (51), optically connecting individual one of said plurality of loop-back optical paths means (51).
Claim 21
Dependent Claim
31 words
An optical device as claimed in claim 2, wherein at least one of said signal processing means (52) is optical node means (121) for transmitting, amplifying, splitting and merging optical signals.
Claim 22
Dependent Claim
27 words
An optical device as claimed in claim 2, wherein at least one of said signal processing means (52) includes photodetector means (53) and an light source (54).
Claim 23
Dependent Claim
19 words
An optical device as claimed in claim 2, wherein said signal processing means (52) is signal delay means (84).
Claim 24
Dependent Claim
19 words
An optical device as claimed in claim 2, wherein said signal processing means (52) is signal amplifier means (57).
Claim 25
Dependent Claim
19 words
An optical device as claimed in claim 2, wherein said signal processing means (52) is wavelength conversion means (101).
Claim 26
Dependent Claim
19 words
An optical device as claimed in claim 2, wherein said signal processing means (52) is optical bistable device (111).
Claim 27
Dependent Claim
20 words
An optical device as claimed in claim 2, wherein said signal processing means (52) is optical pulse regenerating device means.
Claim 28
Dependent Claim
20 words
An optical device as claimed in claim 2, wherein said signal processing means (52) is optical pulse equalizing means (97).
Claim 29
Dependent Claim
20 words
An optical device as claimed in claim 2, wherein said signal processing means (52) is wavelength-selective optical filter means (65).
Claim 30
Dependent Claim
22 words
An optical device as claimed in claim 29, wherein said wavelength-selective optical filter means (52) is an arrayed waveguide grating multi/demultiplexer (41).
Claim 31
Dependent Claim
19 words
An optical device as claimed in claim 29, wherein said wavelength-selective optical filter means (52) is an interference film.
Claim 32
Dependent Claim
19 words
An optical device as claimed in claim 29, wherein said wavelength-selective optical filter means (52) is a ring resonator.
Claim 33
Dependent Claim
19 words
An optical device as claimed in claim 29, wherein said wavelength-selective optical filter means (52) is a Mach-Zehnder interferometer.
References Cited (Backward Citations)
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