Laser wavelength control device
First Claim
1. 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.
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Accused Products
Abstract
A laser control system is disclosed including a microprocessor, which precisely adjusts the wavelength of light output from the laser by monitoring the transmissivity of an in-fiber Bragg grating coupled to the output of the laser. The Bragg grating is fabricated to have a minimum transmissivity at the desired output wavelength of the laser. The microprocessor continually adjusts the wavelength of the laser output to obtain substantially minimal transmissivity through the grating. At which point, the laser is locked to the desired wavelength. Alternatively, the microprocessor can monitor light reflected from the grating, and continually adjust the wavelength of the laser output to lock the laser at a wavelength providing substantially maximum reflectance by the grating.
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Citations
38 Claims
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1. An optical device, comprising:
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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. - View Dependent Claims (2, 3, 4, 5, 6, 38)
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7. An optical device comprising:
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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. - View Dependent Claims (8, 9, 10, 11)
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12. An optical device comprising:
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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. - View Dependent Claims (13, 14, 15, 16, 17)
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18. A method of regulating a wavelength of light output from a laser, comprising the steps of:
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transmitting said light through a partially transmissive element having a transmission characteristic whereby a minimum transmissivity is obtained at a predetermined wavelength; increasing said wavelength in first increments until a transmissivity of said light increases at a first wavelength; decreasing said wavelength in second increments until said transmissivity of said light increases at a second wavelength; and adjusting said wavelength to be a third wavelength between said first and second wavelengths. - View Dependent Claims (19, 20, 21, 22, 23)
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24. A method of regulating a wavelength of light output from a laser, comprising the steps of:
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reflecting said light off a partially reflective element having a reflectivity characteristic whereby a maximum reflectivity is obtained at a predetermined wavelength; increasing said wavelength in first increments until a reflectivity of said partially reflective element decreases at a first wavelength; decreasing said wavelength in second increments until said reflectivity of reflective element decreases at a second wavelength; and adjusting said wavelength to be a third wavelength between said first and second wavelengths. - View Dependent Claims (25, 26, 27, 28, 29)
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30. An optical device, comprising:
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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. - View Dependent Claims (31)
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32. An optical device, comprising:
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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. - View Dependent Claims (33)
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34. An optical device, comprising:
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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. - View Dependent Claims (35)
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36. An optical device, comprising:
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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. - View Dependent Claims (37)
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Specification