Laser wavelength control device

Claim 2

An optical device, comprising: a first source of light, said light having a first wavelength dependent upon a temperature of said first source; a filtering element coupled to said first source of said light; a first photoelectric conversion device configured to detect a portion of said light transmitted through said filtering element and generate an electrical sense signal in response thereto; a control circuit coupled to said first photoelectric conversion device; a temperature regulating device coupled to receive a control signal generated by said control circuit in response to said electrical sense signal, said temperature regulating device adjusting a temperature of said first light source in response to said control signal to thereby adjust said first wavelength; a second source of light at a second wavelength different than said first wavelength; a second photoelectric conversion device coupled to said second source and generating a detection signal in response to said light at said second wavelength for modulating said light at said first wavelength; and a circuit coupled to said second photoelectric conversion device, said second photoelectric conversion device supplying said detection signal to said circuit, said circuit being configured to facilitate modulation of said light at said first wavelength.

Claim 3

An optical device in accordance with claim 1, wherein said circuit further comprising: a modulation circuit coupled to receive said detection signal, said modulation circuit outputting a modulation signal in accordance with said detection signal; and an optical modulator configured to receive said modulation signal to thereby modulate said light at said first wavelength.

Claim 4

An optical device in accordance with claim 1, wherein said source of light comprises a laser.

Claim 5

An optical device in accordance with claim 1, wherein said filtering element comprises an in-fiber Bragg grating.

Claim 6

An optical device in accordance with claim 1, wherein said filtering element has a transmission characteristic whereby a minimum transmittance is obtained at a predetermined wavelength, said first wavelength being substantially equal to said predetermined wavelength.

Claim 7

An optical device in accordance with claim 1, wherein said optical modulator comprises a Mach-Zehnder interferometer.

Claim 8

An optical device comprising: a first source of light at a first wavelength, said first wavelength being dependent upon a temperature of said first source; a reflective element coupled to said source of said first light; a first photoelectric conversion device configured to detect a portion of said light reflected by said reflective element and generate an electrical sense signal in response thereto; a control circuit coupled to said first photoelectric conversion device; a temperature regulating device coupled to receive a control signal generated by said control circuit in response to said electrical sense signal, said temperature regulating device adjusting a temperature of said first light source in response to said control signal to thereby adjust said first wavelength; a second source of light at a second wavelength different than said first wavelength; a second photoelectric conversion device coupled to said second source and generating a detection signal in response to said light at said second wavelength for modulating said light at said first wavelength!; and a circuit coupled to said second photoelectric conversion device, said second photoelectric conversion device supplying said detection signal to said circuit, said circuit being configured to facilitate modulation of said light at said first wavelength.

Claim 9

An optical device comprising: a first source of light at a first wavelength, said first wavelength being dependent upon a temperature of said first source; a reflective element coupled to said source of said first light; a first photoelectric conversion device configured to detect a portion of said light reflected by said reflective element and generate an electrical sense signal in response thereto; a control circuit coupled to said first photoelectric conversion device; a temperature regulating device coupled to receive a control signal generated by said control circuit in response to said electrical sense signal, said temperature regulating device adjusting a temperature of said first light source in response to said control signal to thereby adjust said first wavelength; a second source of light at a second wavelength different than said first wavelength; a second photoelectric conversion device coupled to said second source and generating a detection signal in response to said light at said second wavelength for modulating said light at said first wavelength!; and a circuit coupled to said second photoelectric conversion device, said second photoelectric conversion device supplying said detection signal to said circuit, said circuit being configured to facilitate modulation of said light at said first wavelength.

Claim 10

An optical device in accordance with claim 7, wherein said circuit further comprising: a modulation circuit coupled to receive said detection signal, said modulation circuit outputting a modulation signal in accordance with said detection signal; and an optical modulator configured to receive said modulation signal to modulate said light at said first wavelength.

Claim 11

An optical device in accordance with claim 7, wherein said reflective element comprises an in-fiber Bragg grating.

Claim 12

An optical device in accordance with claim 7, wherein said reflective element has a reflectivity characteristic whereby a maximum reflectance is obtained at a predetermined wavelength, said control circuit adjusting said wavelength to be substantially equal to said predetermined wavelength.

Claim 13

An optical device in accordance with claim 7, wherein said optical modulator circuit comprises a Mach-Zehnder interferometer.

Claim 14

An optical device comprising: a first source of light at a first wavelength; a partially reflective element coupled to said first source of said light at said first wavelength; a first photoelectric conversion device configured to detect a first portion of said light at said first wavelength transmitted through said partially reflective element and generating a first electrical sense signal; a second photoelectric conversion device configured to detect a second portion of said light at said first wavelength reflected by said partially reflective element and generating a second electrical sense signal; a comparator circuit configured to receive said first and second electrical sense signals and generating an output signal corresponding to a comparison between said first and second electrical sense signals; a control circuit coupled to said comparator circuit, said control circuit adjusting said first wavelength of said light in response to said output signal; a second source of light at a second wavelength different than said first wavelength; a third photoelectric conversion device coupled to said second source and generating a detection signal in response to said light at said second wavelength; and a circuit coupled to said second photoelectric conversion device, said second photoelectric conversion device supplying said detection signal to said circuit, said circuit being configured to facilitate modulation of said light at said first wavelength.

Claim 15

An optical device comprising: a first source of light at a first wavelength; a partially reflective element coupled to said first source of said light at said first wavelength; a first photoelectric conversion device configured to detect a first portion of said light at said first wavelength transmitted through said partially reflective element and generating a first electrical sense signal; a second photoelectric conversion device configured to detect a second portion of said light at said first wavelength reflected by said partially reflective element and generating a second electrical sense signal; a comparator circuit configured to receive said first and second electrical sense signals and generating an output signal corresponding to a comparison between said first and second electrical sense signals; a control circuit coupled to said comparator circuit, said control circuit adjusting said first wavelength of said light in response to said output signal; a second source of light at a second wavelength different than said first wavelength; a third photoelectric conversion device coupled to said second source and generating a detection signal in response to said light at said second wavelength; and a circuit coupled to said second photoelectric conversion device, said second photoelectric conversion device supplying said detection signal to said circuit, said circuit being configured to facilitate modulation of said light at said first wavelength.

Claim 16

An optical device in accordance with claim 12, wherein said first source comprises a laser.

Claim 17

An optical device in accordance with claim 12, wherein said partially reflective element comprises an in-fiber Bragg grating.

Claim 18

An optical device in accordance with claim 12, wherein said first wavelength of said light is dependent upon a temperature of said first source, said optical device further comprising: a temperature regulating device coupled to receive a control signal generated by said control circuit in response to said output signal, said temperature regulating device adjusting a temperature of said first source in response to said control signal to thereby adjust said first wavelength.

Claim 19

An optical device in accordance with claim 12, wherein said circuit comprises: a modulation circuit coupled to receive said detection signal, said modulation circuit outputting a modulation signal in accordance with said detection signal; and an optical modulator configured to receive said modulation signal to modulate said light at said first wavelength.

Claim 20

An optical device in accordance with claim 16, wherein said optical modulator comprises a Mach-Zehnder interferometer.

Claim 23

A method in accordance with claim 18, further comprising the steps of: changing said wavelength in third increments less than said first increments until said transmissivity of said light through said filtering element increases at a fourth wavelength between said first and third wavelengths; changing said wavelength in fourth increments less than said second increments until said transmissivity of said light through said filtering element increases at a fifth wavelength between said second and third wavelengths; and adjusting said wavelength to be sixth wavelength between said fourth and fifth wavelengths.

Claim 24

A method in accordance with claim 18, wherein if said first increments are equal to a predetermined value, said method further comprising the steps of: changing said wavelength in said first increments until said transmissivity of said light through said filtering element increases at a fourth wavelength between said first and third wavelengths; changing said wavelength in said second increments until said transmissivity of said light through said filtering element increases at a fifth wavelength between said second and third wavelengths; and adjusting said wavelength to be a sixth wavelength between said fourth and fifth wavelengths.

Claim 25

A method in accordance with claim 18, wherein said increasing step further comprises the steps of: monitoring a temperature of said laser; and delaying successive ones of said first increments of said wavelength at least until said temperature of said laser is substantially constant.

Claim 26

A method in accordance with claim 18, wherein said partially transmissive element comprises an in-fiber Bragg grating, said method further comprising the steps of: monitoring a temperature of said in-fiber Bragg grating; and discontinuing said increasing and decreasing steps when said temperature exceeds a first value or falls below a second value.

Claim 27

A method in accordance with claim 18, further comprising the step of generating an alarm signal when an intensity of said light output from said laser exceeds a first value or falls below a second value.

Claim 30

A method in accordance with claim 24, further comprising the steps of: changing said wavelength in third increments less than said first increments until said reflectivity of said partially reflective element decreases at a fourth wavelength between said second and third wavelengths; changing said wavelength in fourth increments less than said second increments until said reflectivity of said partially reflective element decreases at a fifth wavelength; and adjusting said wavelength to be a sixth wavelength between said fourth and fifth wavelengths.

Claim 31

A method in accordance with claim 24, wherein if said first increments are equal to a predetermined value, said method further comprising the steps of: changing said wavelength in said first increments until said reflectivity of said partially reflective element decreases at a fourth wavelength; changing said wavelength in said second increments until said reflectivity of said partially reflective element decreases at a fifth wavelength; and adjusting said wavelength to be a sixth wavelength between said fourth and fifth wavelengths.

Claim 32

A method in accordance with claim 24, wherein said increasing step further comprises the steps of: monitoring a temperature of said laser; and delaying successive ones of said first increments of said wavelength at least until said temperature of said laser is substantially constant.

Claim 33

A method in accordance with claim 24, wherein said partially reflective element comprises an in-fiber Bragg grating, said method further comprising the steps of: monitoring a temperature of said in-fiber Bragg grating; and discontinuing said increasing and decreasing steps when said temperature exceeds a first value or falls below a second value.

Claim 34

A method in accordance with claim 24, wherein said method further comprising the step of generating an alarm signal when an intensity of said light output from said laser exceeds a first value or falls below a second value.

Claim 35

An optical device, comprising: a laser; an optical filtering element coupled to an output of said laser, said optical filtering element having a transmissivity characteristic in which a minimum transmissivity is obtained at a predetermined wavelength; means, coupled to said laser, for increasing a wavelength of light output from said laser in first increments until a transmissivity of said optical filtering element increases at a first wavelength; means, coupled to said laser, for decreasing said wavelength in second increments until a transmissivity of said optical filtering element increases at a second wavelength; and means, coupled to said laser, for adjusting said wavelength to be a third wavelength between said first and second wavelengths.

Claim 36

An optical device, comprising: a laser; an optical filtering element coupled to an output of said laser, said optical filtering element having a transmissivity characteristic in which a minimum transmissivity is obtained at a predetermined wavelength; means, coupled to said laser, for increasing a wavelength of light output from said laser in first increments until a transmissivity of said optical filtering element increases at a first wavelength; means, coupled to said laser, for decreasing said wavelength in second increments until a transmissivity of said optical filtering element increases at a second wavelength; and means, coupled to said laser, for adjusting said wavelength to be a third wavelength between said first and second wavelengths.

Claim 37

An optical device in accordance with claim 30, wherein said optical filtering element comprises an in-fiber Bragg grating.

Claim 38

An optical device, comprising: a laser; a reflective element coupled to an output of said laser, said reflective element having a reflectivity characteristic in which a maximum reflectivity is obtained at a predetermined wavelength; means, coupled to said laser, for increasing a wavelength of light output from said laser in first increments until a reflectivity of said reflective element decreases at a first wavelength; means, coupled to said laser, for decreasing said wavelength in second increments until a reflectivity of said reflective element decreases at a second wavelength; and means, coupled to said laser, for adjusting said wavelength to be a third wavelength between said first and second wavelengths.

Claim 39

An optical device, comprising: a laser; a reflective element coupled to an output of said laser, said reflective element having a reflectivity characteristic in which a maximum reflectivity is obtained at a predetermined wavelength; means, coupled to said laser, for increasing a wavelength of light output from said laser in first increments until a reflectivity of said reflective element decreases at a first wavelength; means, coupled to said laser, for decreasing said wavelength in second increments until a reflectivity of said reflective element decreases at a second wavelength; and means, coupled to said laser, for adjusting said wavelength to be a third wavelength between said first and second wavelengths.

Claim 40

An optical device in accordance with claim 32, wherein said filtering element comprises an in-fiber Bragg grating.

Claim 41

An optical device, comprising: a laser; an optical filtering element coupled to an output of said laser, said optical filtering element having a transmissivity characteristic in which a minimum transmissivity is obtained at a predetermined wavelength and a reflectivity characteristic in which a peak reflectivity is obtained at said predetermined wavelength; means for detecting a first portion of said output of said laser reflected from said optical filtering element and generating a first detection signal; means for detecting a second portion of said light output from said laser transmitted through said optical filtering element and generating a second detection signal; means for comparing said first and second detection signals; means for increasing a wavelength of light output from said laser in first increments in response to said comparison until a transmissivity of said optical filtering element increases at a first wavelength; means for decreasing said wavelength in second increments in response to said comparison until a transmissivity of said optical filtering element increases at a second wavelength; and means, coupled to said laser, for adjusting said wavelength to be a third wavelength between said first and second wavelengths.

Claim 42

An optical device, comprising: a laser; an optical filtering element coupled to an output of said laser, said optical filtering element having a transmissivity characteristic in which a minimum transmissivity is obtained at a predetermined wavelength and a reflectivity characteristic in which a peak reflectivity is obtained at said predetermined wavelength; means for detecting a first portion of said output of said laser reflected from said optical filtering element and generating a first detection signal; means for detecting a second portion of said light output from said laser transmitted through said optical filtering element and generating a second detection signal; means for comparing said first and second detection signals; means for increasing a wavelength of light output from said laser in first increments in response to said comparison until a transmissivity of said optical filtering element increases at a first wavelength; means for decreasing said wavelength in second increments in response to said comparison until a transmissivity of said optical filtering element increases at a second wavelength; and means, coupled to said laser, for adjusting said wavelength to be a third wavelength between said first and second wavelengths.

Claim 43

An optical device in accordance with claim 34, wherein said optical filtering element comprises an in-fiber Bragg grating.

Claim 44

An optical device, comprising: a laser; an optical filtering element coupled to an output of said laser, said optical filtering element having a transmissivity characteristic in which a minimum transmissivity is obtained at a predetermined wavelength and a reflectivity characteristic in which a peak reflectivity is obtained at said predetermined wavelength; means for detecting a first portion of said output of said laser reflected from said optical filtering element and generating a first detection signal; means for detecting a second portion of said light output from said laser transmitted through said optical filtering element and generating a second detection signal; means for comparing said first and second detection signals; means for increasing a wavelength of light output from said laser in first increments in response to said comparison until a reflectivity of said optical filtering element decreases at a first wavelength; means for decreasing said wavelength in second increments in response to said comparison until a reflectivity of said optical filtering element decreases at a second wavelength; and means, coupled to said laser, for adjusting said wavelength to be a third wavelength between said first and second wavelengths.

Claim 45

An optical device, comprising: a laser; an optical filtering element coupled to an output of said laser, said optical filtering element having a transmissivity characteristic in which a minimum transmissivity is obtained at a predetermined wavelength and a reflectivity characteristic in which a peak reflectivity is obtained at said predetermined wavelength; means for detecting a first portion of said output of said laser reflected from said optical filtering element and generating a first detection signal; means for detecting a second portion of said light output from said laser transmitted through said optical filtering element and generating a second detection signal; means for comparing said first and second detection signals; means for increasing a wavelength of light output from said laser in first increments in response to said comparison until a reflectivity of said optical filtering element decreases at a first wavelength; means for decreasing said wavelength in second increments in response to said comparison until a reflectivity of said optical filtering element decreases at a second wavelength; and means, coupled to said laser, for adjusting said wavelength to be a third wavelength between said first and second wavelengths.

Claim 46

An optical device in accordance with claim 36, wherein said optical filtering element comprises an in-fiber Bragg grating.

Claim 47

An optical device in accordance with claim 4, wherein said in-fiber Bragg grating has a spectral width substantially equal to one angstrom.