Patent US5025448A successfully refreshed from Google Patents.
US5025448A
Expired / Lapsed
US
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Method and apparatus for stabilizing frequency of semiconductor laser
Assignee: NTT Inc
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Filing: 1990-03-13
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Granted: 1991-06-18
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Expires: 2010-03-13
Abstract
Abstract A method of stabilizing the frequency of a semiconductor laser comprises stabilizing a time-dependent frequency fluctuation by utilizing an optical energy absorption medium including an isotope acetylene gas molecule. An apparatus for stabilizing the frequency of a semiconductor laser, comprises a semiconductor laser, an optical energy absorption medium, a photodetector and a control circuit as essential elements. The optical energy absorption medium includes an isotope acetylene molecule.
Inventors
- 👤 Shoichi Sudo
- 👤 Yoshihisa Sakai
- 👤 Hiroshi Yasaka
- 👤 Tetsuhiko Ikegami
- 👤 Yuzo Yoshikuni
- 👤 Itaru Yokohama
- 👤 Kenichi Kubodera
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:02
CPC Classifications
H; H04; H04B; H04B10/00; H04B10/50; H04B10/572; G; G02; G02B; G02B6/00; G02B6/24; G02B6/26; G02B6/262; G02B6/42; G02B6/4201; G02B6/4204; H01; H01S; H01S5/00; H01S5/06; H01S5/068; H01S5/0683; H01S5/0687; H04B10/501; H04B10/503; H01S5/02; H01S5/022; H01S5/0225; H01S5/02251; H01S5/40; H01S5/4025; H01S5/4031
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
158 words
A semiconductor laser apparatus including means for stabilizing the frequency thereof, said apparatus comprising: a semiconductor laser means for emitting light; a frequency modulating means for frequency modulating a light output from said semiconductor laser means; an optical energy absorbing medium for absorbing optical energy, said optical energy absorbing medium being enclosed within a space such that frequency modulated light output from said frequency modulating means is incident on said optical energy absorbing medium; photodetector means for converting said frequency modulated light transmitted through said optical energy absorbing medium to an electrical signal; and control circuit means for stabilizing the frequency of light output from said semiconductor laser means in response to said electrical signal output from said photodetector means; wherein said optical energy absorbing medium comprises acetylene gas enclosed within said space, and wherein among carbon and hydrogen atoms of which molecules of said acetylene as are comprised, at least one atom is of a selected isotope.
Claim 2
Dependent Claim
158 words
A semiconductor laser apparatus including means for stabilizing the frequency thereof, said apparatus comprising: a semiconductor laser means for emitting light; a frequency modulating means for frequency modulating a light output from said semiconductor laser means; an optical energy absorbing medium for absorbing optical energy, said optical energy absorbing medium being enclosed within a space such that frequency modulated light output from said frequency modulating means is incident on said optical energy absorbing medium; photodetector means for converting said frequency modulated light transmitted through said optical energy absorbing medium to an electrical signal; and control circuit means for stabilizing the frequency of light output from said semiconductor laser means in response to said electrical signal output from said photodetector means; wherein said optical energy absorbing medium comprises acetylene gas enclosed within said space, and wherein among carbon and hydrogen atoms of which molecules of said acetylene as are comprised, at least one atom is of a selected isotope.
Claim 3
Dependent Claim
26 words
An apparatus in accordance with claim 1, wherein said acetylene gas enclosed within said space is under a reduced pressure of no more than 1 atm.
Claim 4
Dependent Claim
44 words
An apparatus in accordance with claim 1, wherein said optical energy absorbing medium comprises a mixtures of said acetylene gas and at least one component selected from the group consisting of helium gas, neon gas, argon gas, oxygen gas, nitrogen gas and hydrogen gas.
Claim 5
Dependent Claim
54 words
An apparatus in accordance with claim 3, comprising an optical fiber including a core and a cladding, said optical fiber having a closed hollow area within said core which defines said space, and wherein said optical energy absorbing medium is enclosed within said closed hollow area of said optical fiber under a predetermined pressure.
Claim 6
Dependent Claim
54 words
An apparatus in accordance with claim 1, comprising an optical fiber including a core and a cladding, said optical fiber having a closed hollow area within said core which defines said space, and wherein said optical energy absorbing medium is enclosed within said closed hollow area of said optical fiber under a predetermined pressure.
Claim 7
Dependent Claim
55 words
An apparatus in accordance with claim 3, comprising an optical fiber including a core and a cladding, said optical fiber comprising a closed hollow area adjacent to said core which defines said space, and wherein said optical energy absorbing medium is enclosed within said closed hollow area of said optical fiber under a predetermined pressure.
Claim 8
Dependent Claim
55 words
An apparatus in accordance with claim 1, comprising an optical fiber including a core and a cladding, said optical fiber having a closed hollow area adjacent to said core which defines said space, and wherein said optical energy absorbing medium is enclosed within said closed hollow area of said optical fiber under a predetermined pressure.
Claim 9
Dependent Claim
31 words
An apparatus in accordance with claim 1, wherein at least one of said semiconductor laser means and said photodetector means is provided within said space enclosing said optical energy absorbing medium.
Claim 10
Dependent Claim
63 words
An apparatus in accordance with claim 1, comprising a cell which defines said space and which encloses said optical energy absorbing medium, said cell comprising a condenser lens located on an input-surface thereof on which said frequency modulated light is incident, and wherein said photodetector means is located directly on an output-surface of said cell from which said frequency modulated light is output.
Claim 11
Dependent Claim
63 words
An apparatus in accordance with claim 1, comprising a cell which defines said space and which encloses said optical energy absorbing medium, said cell comprising a condenser lens located on an input-surface thereof on which said frequency modulated light is incident, and wherein said photodetector means is located adjacent to an output-surface of said cell from which said frequency modulated light is output.
Claim 12
Dependent Claim
75 words
An apparatus in accordance with claim 1, further comprising: a cell defining said space and which encloses said optical energy absorbing medium; at least one input optical fiber for inputting said frequency modulated light to said cell; and at least one output optical fiber for outputting said frequency-modulated light from within said cell; and wherein said at least one input optical fiber and said at least one output optical fiber are connected to said cell.
Claim 13
Dependent Claim
47 words
An apparatus in accordance with claim 1, wherein said semiconductor laser means, said frequency modulating means and said photodetector means are respectively provided with at least one of at least one input optical fiber for inputting light and at least one output optical fiber for outputting light.
Claim 14
Independent Claim
136 words
A method for stabilizing the frequency of a semiconductor laser apparatus, comprising: frequency modulating a light output of a semiconductor laser; enclosing an optical energy absorbing medium, for absorbing optical energy, within a space such that frequency modulated light output from said frequency modulating means is incident on said optical energy absorbing medium; converting said frequency modulated light transmitted through said optical energy absorbing medium to an electrical signal; and stabilizing the frequency of light output from said semiconductor laser means, by means of a control circuit, in response to said electrical signal output from said photodetector means; wherein said optical energy absorbing medium comprises acetylene gas enclosed within said space, and wherein among carbon and hydrogen atoms of which molecules of said acetylene gas are comprised, at least one atom is of a selected isotope.
Claim 15
Independent Claim
136 words
A method for stabilizing the frequency of a semiconductor laser apparatus, comprising: frequency modulating a light output of a semiconductor laser; enclosing an optical energy absorbing medium, for absorbing optical energy, within a space such that frequency modulated light output from said frequency modulating means is incident on said optical energy absorbing medium; converting said frequency modulated light transmitted through said optical energy absorbing medium to an electrical signal; and stabilizing the frequency of light output from said semiconductor laser means, by means of a control circuit, in response to said electrical signal output from said photodetector means; wherein said optical energy absorbing medium comprises acetylene gas enclosed within said space, and wherein among carbon and hydrogen atoms of which molecules of said acetylene gas are comprised, at least one atom is of a selected isotope.
Claim 16
Dependent Claim
26 words
A method in accordance with claim 13, comprising maintaining said acetylene gas enclosed within said space under a reduced pressure of no more than 1 atm.
Claim 17
Dependent Claim
44 words
A method in accordance with claim 13, wherein said optical energy absorbing medium comprises a mixture of said acetylene gas and at least one component selected from the group consisting of helium gas, neon gas, argon gas, oxygen gas, nitrogen gas and hydrogen gas.
Claim 18
Dependent Claim
52 words
An apparatus in accordance with claim 15, comprising an optical fiber including a core and a cladding, and wherein said enclosing step comprises enclosing said optical energy absorbing medium within a closed hollow area within said core of said optical fiber under a predetermined pressure, said closed hollow area defining said space.
Claim 19
Dependent Claim
52 words
An apparatus in accordance with claim 13, comprising an optical fiber including a core and a cladding, and wherein said enclosing step comprises enclosing said optical energy absorbing medium within a closed hollow area within said core of said optical fiber under a predetermined pressure, said closed hollow area defining said space.
Claim 20
Dependent Claim
52 words
A method in accordance with claim 15, comprising an optical fiber including a core and a cladding, and wherein said enclosing step comprises enclosing said optical energy absorbing medium within a closed hollow area adjacent said core of said optical fiber under a predetermined pressure, said closed hollow area defining said space.
Claim 21
Dependent Claim
52 words
A method in accordance with claim 13, comprising an optical fiber including a core and a cladding, and wherein said enclosing step comprises enclosing said optical energy absorbing medium within a closed hollow area adjacent said core of said optical fiber under a predetermined pressure, said closed hollow area defining said space.
Claim 22
Dependent Claim
37 words
An apparatus in accordance with claim 1, comprising providing said semiconductor laser apparatus with at least one of at least one input optical fiber for inputting light and at least one output optical fiber for outputting light.
References Cited (Backward Citations)
US3593189A
Cited
US3742382A
Cited
US3842367A
Cited
US3921099A
Cited
US4829533A
Cited
US4833681A
Cited
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