US5007698A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical fiber amplifier/multiplexer
Assignee: Fujitsu Ltd
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Filing: 1990-08-15
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Granted: 1991-04-16
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Expires: 2010-08-15
Abstract
Abstract An optical waveguide having a first cross section is thinned to constitute a thinned portion having a second cross section, as long as a predetermined length. Surface of the thinned portion is contacted with a laser glass member doped with a rare earth element, such as Er. Due to the thinned diameter, the optical fiber is optically coupled with the laser glass member. A pumping light is input to either into the optical waveguide together with a signal light or directly into the laser glass member. Signal light coupled from the thinned portion to the laser glass member is amplified by stimulated emission of the laser glass. Thus amplified signal light is coupled back to the thinned portion so as to propagate along the optical waveguide. The thinned portion can be as short as several centi-meters compared with ten meters to more than one hundred meters of conventional optical amplifier. In the optical waveguide where the pumping light is directly input to the laser glass member, the complicated multiplexer is not necessary, resulting in a reliable operation of the amplifier.
Inventors
- 👤 Kazuya Sasaki
- 👤 Sakae Yoshizawa
- 👤 Shinya Inagaki
- 👤 Keiko Takeda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:20
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/05; H01S3/06; H01S3/063
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
62 words
An optical waveguide amplifier for amplifying an optical signal propagating therein, comprising: a laser glass member, doped with a rare earth element, and optical waveguide means, including: input end means for receiving the optical signal from a light source, and amplifying means, formed substantially thinner than the input end means, for contacting the laser glass member and for amplifying the optical signal.
Claim 2
Dependent Claim
62 words
An optical waveguide amplifier for amplifying an optical signal propagating therein, comprising: a laser glass member, doped with a rare earth element, and optical waveguide means, including: input end means for receiving the optical signal from a light source, and amplifying means, formed substantially thinner than the input end means, for contacting the laser glass member and for amplifying the optical signal.
Claim 3
Dependent Claim
16 words
An optical amplifier as recited in claim 1, wherein the optical waveguide is an optical fiber.
Claim 4
Dependent Claim
32 words
An optical amplifier as recited in claim 1, wherein a second cross section of the amplifying means is approximately 8 to 40% of a first cross section of the input end means.
Claim 5
Dependent Claim
32 words
An optical amplifier as recited in claim 2, wherein said second cross section of the amplifying means has approximately 10 to 50 μm diameter for amplifying an approximately 1.536 μm wavelength light.
Claim 6
Dependent Claim
37 words
An optical amplifier as recited in claim 1, wherein the optical transmission line is an optical thin base material waveguide formed in a glass substrate, said optical thin base material waveguide having a width and a thickness.
Claim 7
Dependent Claim
24 words
An optical amplifier as recited in claim 5, wherein said second cross section is thinner than said first cross section while same in width.
Claim 8
Dependent Claim
24 words
An optical amplifier as recited in claim 5, wherein said second cross section is wider than said first cross section while same in thickness.
Claim 9
Dependent Claim
22 words
An optical amplifier as recited in claim 5, wherein said glass member is formed in an adjacent portion of said glass substrate.
Claim 10
Dependent Claim
37 words
An optical amplifier as recited in claim 1, wherein the optical waveguide is a ridge-type optical thin base material waveguide formed on a glass substrate, said optical thin base material waveguide having a width and a thickness.
Claim 11
Dependent Claim
21 words
An optical amplifier as recited in claim 9, wherein said glass member is formed over and on sides of said ridge.
Claim 12
Dependent Claim
49 words
An optical amplifier as recited in claim 1, wherein a slope of transition from said first cross section to said second cross section is symmetrical to a slope of transition from said second cross section to said first cross section with respect to a midpoint of said thinned portion.
Claim 13
Dependent Claim
43 words
An optical amplifier as recited in claim 1, wherein said laser glass member is doped with a dopant selected from a group of erbium; neodymium; ytterbium; samarium and praseodymium, wherein an amount of said dopant is approximately ten ppm to several thousands ppm.
Claim 14
Dependent Claim
50 words
An optical amplifier as recited in claim 1, wherein said laser glass member is doped with a dopant selected from a group of erbium; neodymium; ytterbium; samarium and praseodymium, and aluminum in addition thereto, wherein an amount of said aluminum is several hundreds ppm to several tens of thousands ppm.
Claim 15
Dependent Claim
99 words
An optical amplifier, for amplifying a signal light propagating in an optical waveguide having a first cross section, comprising: a thinned portion of said optical waveguide, said thinned portion having a second cross section substantially smaller than said first cross section; a glass member formed of a laser glass material doped with a rare earth element, said glass member contacting said thinned portion; and a multiplexer provided on said optical waveguide, for introducing a pumping light into said optical waveguide so as to propagate into said thinned portion, whereby said light output from said thinned portion has been amplified.
Claim 16
Dependent Claim
99 words
An optical amplifier, for amplifying a signal light propagating in an optical waveguide having a first cross section, comprising: a thinned portion of said optical waveguide, said thinned portion having a second cross section substantially smaller than said first cross section; a glass member formed of a laser glass material doped with a rare earth element, said glass member contacting said thinned portion; and a multiplexer provided on said optical waveguide, for introducing a pumping light into said optical waveguide so as to propagate into said thinned portion, whereby said light output from said thinned portion has been amplified.
Claim 17
Dependent Claim
25 words
An optical amplifier as recited in claim 14, wherein said multiplexer is located at an input side of the signal light to said thinned portion.
Claim 18
Dependent Claim
25 words
An optical amplifier as recited in claim 14, wherein said multiplexer is located at an output side of the signal light from said thinned portion.
Claim 19
Dependent Claim
32 words
An optical amplifier as recited in claim 14, further comprising a demultiplexer provided on said optical waveguide, wherein said pumping light propagating from said thinned portion is removed from said optical waveguide.
Claim 20
Dependent Claim
23 words
An optical amplifier as recited in claim 17, wherein said demultiplexer is located opposite from said multiplexer with respect to said thinned portion.
Claim 21
Dependent Claim
28 words
An optical amplifier as recited in claim 17, wherein said optical waveguide; said thinned portion; said multiplexer; and said demultiplexer are formed in or on a glass substrate.
Claim 22
Dependent Claim
90 words
An optical amplifier, for amplifying a light propagating in an optical waveguide having a first cross section, comprising: a thinned portion of said optical waveguide, said thinned portion having a second cross section substantially smaller than said first cross section; a glass member formed of a laser glass material, said glass member contacting said thinned portion; and a light source for emitting a pumping light to be introduced into said glass member via a surface of said glass member, whereby said light output from said thinned portion has been amplified.
Claim 23
Dependent Claim
90 words
An optical amplifier, for amplifying a light propagating in an optical waveguide having a first cross section, comprising: a thinned portion of said optical waveguide, said thinned portion having a second cross section substantially smaller than said first cross section; a glass member formed of a laser glass material, said glass member contacting said thinned portion; and a light source for emitting a pumping light to be introduced into said glass member via a surface of said glass member, whereby said light output from said thinned portion has been amplified.
Claim 24
Dependent Claim
25 words
An optical amplifier as recited in claim 20, wherein said glass member has a curved surface and a flat surface for receiving said pumping light.
Claim 25
Dependent Claim
24 words
An optical amplifier as recited in claim 20, wherein said curved surface reflects said received pumping light to a vicinity of said thinned portion.
Claim 26
Dependent Claim
39 words
An optical amplifier as recited in claim 20 further comprising a substrate on which said thinned portion and said light source are installed, said pumping light being introduced via a hole provided on said substrate to said glass member.
Claim 27
Dependent Claim
24 words
An optical amplifier as recited in claim 20 further comprising a lens or a transparent plate, between said glass member and said light source.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-04-15 | 1994-10-15 | 1995-04-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-04-15 | 1998-10-15 | 1999-04-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-04-15 | 2002-10-15 | 2003-04-16 | $7700.00 | Window Closed / Lapsed |