WO2014190646A1 - 波长可调的激光输出方法和可调激光装置 - Google Patents

波长可调的激光输出方法和可调激光装置 Download PDF

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Publication number
WO2014190646A1
WO2014190646A1 PCT/CN2013/084376 CN2013084376W WO2014190646A1 WO 2014190646 A1 WO2014190646 A1 WO 2014190646A1 CN 2013084376 W CN2013084376 W CN 2013084376W WO 2014190646 A1 WO2014190646 A1 WO 2014190646A1
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laser
optical signal
frequency
wavelength
temperature
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PCT/CN2013/084376
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English (en)
French (fr)
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代溪泉
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华为技术有限公司
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Priority to EP13876085.5A priority Critical patent/EP2835883A4/en
Priority to US14/485,983 priority patent/US20150023672A1/en
Publication of WO2014190646A1 publication Critical patent/WO2014190646A1/zh

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/50—Transmitters
    • H04B10/501—Structural aspects
    • H04B10/503—Laser transmitters
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/50—Transmitters
    • H04B10/572—Wavelength control
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/02—Structural details or components not essential to laser action
    • H01S5/024—Arrangements for thermal management
    • H01S5/02407—Active cooling, e.g. the laser temperature is controlled by a thermo-electric cooler or water cooling
    • H01S5/02415—Active cooling, e.g. the laser temperature is controlled by a thermo-electric cooler or water cooling by using a thermo-electric cooler [TEC], e.g. Peltier element
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/02—Structural details or components not essential to laser action
    • H01S5/024—Arrangements for thermal management
    • H01S5/02438—Characterized by cooling of elements other than the laser chip, e.g. an optical element being part of an external cavity or a collimating lens
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/10—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region
    • H01S5/14—External cavity lasers
    • H01S5/141—External cavity lasers using a wavelength selective device, e.g. a grating or etalon
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/10—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
    • H01S3/106—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating by controlling devices placed within the cavity
    • H01S3/1062—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating by controlling devices placed within the cavity using a controlled passive interferometer, e.g. a Fabry-Perot etalon
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/02—Structural details or components not essential to laser action
    • H01S5/022—Mountings; Housings
    • H01S5/0225—Out-coupling of light
    • H01S5/02251—Out-coupling of light using optical fibres
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/06—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
    • H01S5/068—Stabilisation of laser output parameters
    • H01S5/06804—Stabilisation of laser output parameters by monitoring an external parameter, e.g. temperature
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/06—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
    • H01S5/068—Stabilisation of laser output parameters
    • H01S5/0683—Stabilisation of laser output parameters by monitoring the optical output parameters
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/10—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region
    • H01S5/1039—Details on the cavity length

Definitions

  • Wavelength-adjustable laser output method and tunable laser device The application is submitted to the Chinese Patent Office on May 31, 2013, and the application number is 201310211285. 9. The invention is entitled "Wavelength-adjustable laser output method and tunable laser device" The priority of the Chinese Patent Application, the entire contents of which is incorporated herein by reference.
  • TECHNICAL FIELD The present invention relates to the field of optical communication technologies, and in particular, to a wavelength-adjustable laser output method and a tunable wavelength laser device.
  • DWDM Dense Wavelength Division Multiplexing
  • other optical communication fields laser sources that can be adjusted in wavelength are required to achieve flexible configuration of network nodes and rescheduling of wavelengths.
  • the commonly used tunable lasers are: SBR grating 235-DBR laser, External Cavity Tunable Laser-Tunable ECL, and Distributed Feedback Laser Array tunable laser (DFB Laser Array) Wait.
  • SBR grating 235-DBR laser External Cavity Tunable Laser-Tunable ECL
  • DFB Laser Array Distributed Feedback Laser Array tunable laser
  • the embodiment of the invention provides a wavelength-adjustable laser output method and a tunable laser device, which can realize a simple and low-cost wavelength-adjustable laser output method, and by changing the operating temperature of the tunable laser device,
  • the control mode changes the center wavelength of the multi-longitudinal mode optical signal, thereby realizing a simple, low-cost optical signal output of a tunable wavelength.
  • an embodiment of the present invention provides a wavelength-adjustable laser output method, the method comprising: the thermoelectric cooler adjusting an operating temperature of the laser according to the received control signal, thereby causing the laser to excite the current operating temperature. a plurality of longitudinal mode optical signals, and causing the plurality of longitudinal mode optical signals to correspond to a transmission peak of the filter at a peak wavelength;
  • a mirror reflects a portion of the single frequency optical signal back to the laser;
  • the laser locks the operating frequency according to the received central wavelength of the single-frequency optical signal, generates a frequency-locked optical signal having the same wavelength as the central wavelength of the single-frequency optical signal, and outputs the frequency-locked optical signal.
  • thermoelectric cooler adjusts an operating temperature of the laser according to the received control signal, so that the laser excites the multi-longitudinal mode optical signal corresponding to the current working temperature, and causes the plurality of The longitudinal mode optical signal corresponding to the transmission peak of the filter at the peak wavelength specifically includes:
  • thermoelectric cooler adjusts the operating temperature of the laser to the first temperature according to the received first control signal, thereby causing the laser to excite the first multi-longitudinal corresponding to the first operating temperature.
  • thermoelectric cooler adjusts the operating temperature of the laser to the second temperature according to the received second control signal, so that the laser excites the second multi-longitudinal corresponding to the second operating temperature.
  • first temperature and the second temperature are both within an allowable operating temperature range of the laser; and when the first temperature is not equal to the second temperature, the first peak wavelength and the second peak The wavelengths are not the same.
  • the method further includes:
  • the backlight detector detects the illuminating power of the laser, generates a corresponding power feedback signal and sends it to an external control circuit for controlling the illuminating power of the laser to generate a multi-longitudinal mode optical signal having a constant peak wavelength.
  • the method further includes:
  • the temperature detector detects the operating temperature of the laser to generate a corresponding temperature feedback signal for the laser to generate a corresponding temperature adjustment signal according to the temperature feedback signal to adjust the operating temperature of the laser.
  • an embodiment of the present invention provides a tunable laser device, including: a thermoelectric cooler, a laser, a filter, and a mirror;
  • thermoelectric cooler for adjusting an operating temperature of the laser according to the received control signal
  • a laser for exciting a plurality of longitudinal mode optical signals corresponding to a current operating temperature, and wherein the plurality of longitudinal mode optical signals correspond to a transmission peak of the filter at a peak wavelength;
  • a filter configured to filter the multi-longitudinal mode optical signal to obtain a single-frequency optical signal corresponding to the peak wavelength frequency
  • the laser is further configured to generate and output a frequency-locked optical signal having the same wavelength as a center wavelength of the single-frequency optical signal according to the received central wavelength locking operating frequency of the single-frequency optical signal.
  • thermoelectric cooler is specifically configured to:
  • thermoelectric cooler adjusts the operating temperature of the laser to the first temperature according to the received first control signal, thereby causing the laser to excite the first multi-longitudinal corresponding to the first operating temperature.
  • the thermoelectric cooler adjusts the operating temperature of the laser to the second temperature according to the received second control signal, so that the laser excites the second multi-longitudinal corresponding to the second operating temperature.
  • the device further includes a backlight detector, configured to detect the illuminating power of the laser, generate a corresponding power feedback signal, and send the signal to the external control circuit for controlling the illuminating of the laser.
  • Power producing a multi-longitudinal mode optical signal with a constant peak wavelength.
  • the device further includes a temperature detector, configured to detect an operating temperature of the laser, and generate a corresponding temperature adjustment signal; the temperature adjustment signal is used to adjust an operating temperature of the laser .
  • the apparatus further includes an optical isolator for blocking an optical signal from entering the laser through the optical isolator.
  • the laser, the filter and the mirror are fixedly mounted on the thermoelectric cooler.
  • FIG. 1 is a flowchart of a wavelength-adjustable laser output method according to an embodiment of the present invention
  • FIG. 2 is a schematic diagram of spectral characteristics of a wavelength-adjustable laser output method according to an embodiment of the present invention
  • FIG. 3 is a schematic diagram of locking of an IL-FP laser according to an embodiment of the present invention
  • 4 is a second schematic diagram of spectral characteristics of a wavelength-adjustable laser output method according to an embodiment of the present invention
  • FIG. 5 is a schematic diagram of a tunable laser device according to an embodiment of the present invention
  • FIG. 6 is a schematic diagram of an IL-FP laser according to an embodiment of the present invention.
  • FIG. 7 is a schematic diagram of a filter according to an embodiment of the present disclosure.
  • FIG. 8 is a schematic diagram of another filter according to an embodiment of the present invention.
  • the wavelength-adjustable laser output method includes the following steps:
  • Step 110 The thermoelectric cooler adjusts an operating temperature of the laser according to the received control signal, so that the laser excites the multi-longitudinal mode optical signal corresponding to the current working temperature, and causes the multi-longitudinal mode optical signal to be filtered at a peak wavelength. Corresponding to the transmission peak of the device;
  • the external control circuit sends a control signal to the tunable laser device, wherein the control signal may be a direct current signal, which is received by the thermoelectric cooler of the tunable laser device, and the thermoelectric cooler of the tunable laser device has its own temperature according to the control signal. Control adjustment is made to change the temperature signal at the laser end of the tunable laser device, and the temperature is raised or lowered according to the control signal.
  • the laser receives an externally transmitted current signal and is excited by the current signal to emit a plurality of longitudinal mode optical signals, and the control signal controls the adjusted temperature to enable the multi-longitudinal mode optical signal at the peak wavelength and the filter.
  • the transmission peak corresponds.
  • the spectral characteristics of the multi-longitudinal mode optical signal are shown in Figure B, and the transmission peak-frequency characteristic of the filter is shown in Figure 2A. It can be seen that in this particular example, the peak wavelength position of the multi-longitudinal mode optical signal corresponds to a transmission peak of the filter.
  • the laser is preferably an IL-FP laser.
  • Step 120 The filter performs filtering processing on the multiple longitudinal mode optical signals to obtain a single frequency optical signal corresponding to the peak wavelength frequency.
  • the filter receives the multi-longitudinal mode optical signal, and performs filtering processing to filter the multi-longitudinal mode optical signal into a single-frequency optical signal.
  • the first multi-longitudinal mode optical signal shown in FIG. 2B is subjected to the filtering process to obtain a single-frequency optical signal of the spectral characteristics shown in FIG. Step 130, the mirror reflects a portion of the single-frequency optical signal back to the laser;
  • the filtered single-frequency optical signal is partially reflected by the mirror and returned to the laser through the original optical path to form the injected light of the laser.
  • Step 140 The laser locks the operating frequency according to the received central wavelength of the single-frequency optical signal, and generates a locked-frequency optical signal having the same wavelength as the central wavelength of the single-frequency optical signal and outputs the same.
  • the IL-FP laser has an injection-locking characteristic, thereby operating in an injection locking mode and emitting a frequency-locked optical signal having the same wavelength as a central wavelength of the partially reflected single-frequency optical signal.
  • the central wavelength refers to the wavelength corresponding to the spectral luminous intensity or the maximum radiated power energy in the wavelength range.
  • the method further comprises collimating the locked-frequency optical signal to enable the fixed-frequency optical signal to be accurately transmitted to the output optical fiber of the tunable laser device, and performing the locked-frequency optical signal through the output optical fiber.
  • the transmission is such that the tunable laser device supplies a single-frequency laser signal of a certain center wavelength to the outside.
  • the center wavelength of the frequency-locked optical signal is the same as the center wavelength of the single-frequency optical signal in the foregoing step 130, and the center wavelength of the single-frequency optical signal is filtered by the multi-longitudinal optical signal generated by the laser at the current operating temperature. owned.
  • a single frequency of the frequency-locked optical signal output corresponding to the peak wavelength of the multi-longitudinal mode optical signal can be obtained by filtering processing the multi-longitudinal mode optical signal generated by the laser at a certain operating temperature.
  • the above embodiment illustrates the operation of the tunable laser device.
  • the wavelength adjustment principle of the tunable laser device will be described below with reference to FIG.
  • the thermoelectric cooler adjusts the operating temperature of the laser to the first temperature according to the received first control signal, so that the laser excites the first multi-longitudinal mode light corresponding to the first working temperature And causing the first plurality of longitudinal mode optical signals to correspond to a transmission peak of the filter at a first peak wavelength; wherein the first temperature is within an allowable operating temperature range of the laser.
  • the spectral characteristics of the first multi-longitudinal mode optical signal are shown in the solid line portion of Figure B, and the transmission peak-frequency characteristic of the filter is shown in Figure 4A. It can be seen that the first peak wavelength of the first plurality of longitudinal mode optical signals corresponds to a transmission peak of the filter.
  • the filter filters the first multi-longitudinal mode optical signal to obtain a first single-frequency optical signal corresponding to the first peak wavelength frequency; the mirror reflects a portion of the first single-frequency optical signal back to the laser, and the laser receives the
  • the center wavelength of the first single-frequency optical signal is locked to its operating frequency, and a first frequency-locked optical signal having the same wavelength as the center wavelength of the first single-frequency optical signal is generated and output.
  • the first frequency-locked optical signal is shown in the solid line of Figure C in Figure 4.
  • the thermoelectric cooler adjusts the operating temperature of the laser to the second temperature according to the received second control signal, thereby causing the laser to excite the second work
  • the thermoelectric cooler adjusts the operating temperature of the laser to the second temperature according to the received second control signal, thereby causing the laser to excite the second work
  • the operating temperature range is allowed, and when the first temperature is not equal to the second temperature, the first peak wavelength is different from the second peak wavelength.
  • the spectral characteristics of the second plurality of longitudinal mode optical signals are shown in the broken line portion of Figure B, and the transmission peak-frequency characteristic of the filter is also shown in Figure 4A.
  • the second peak wavelength of the second plurality of longitudinal mode optical signals corresponds to another transmission peak of the filter. Further, the second peak wavelength is different from the first peak wavelength, and the transmission peak of the filter corresponding to the first peak wavelength and the second peak wavelength is also different. It can be seen that the change in temperature controlled by the control signal causes the multi-longitudinal mode optical signal generated by the laser to change at the peak wavelength (i.e., frequency).
  • the filter filters the second plurality of longitudinal mode optical signals to obtain a second single frequency optical signal corresponding to the second peak wavelength frequency; the mirror reflects a portion of the second single frequency optical signal back to the laser, and the laser receives the
  • the center wavelength of the second single-frequency optical signal is locked to its operating frequency, and a second locked-frequency optical signal having the same wavelength as the central wavelength of the second single-frequency optical signal is generated and output.
  • the second frequency-locked optical signal is as shown in the broken line portion of C in FIG.
  • the peak wavelength of the multi-longitudinal mode optical signal ie, the first peak wavelength and the second peak wavelength
  • the first single frequency generated based on the first peak wavelength is generated.
  • the optical signal is also different from the frequency of the second single-frequency optical signal generated based on the second peak wavelength, and the wavelength (ie, frequency) of the second frequency-locked optical signal generated by the second single-frequency optical signal injected into the locked laser is first
  • the wavelength (ie, frequency) of the locked-frequency optical signal is also different.
  • the backlight detector of the tunable laser device can also detect the illuminating power of the laser, and can generate a corresponding power feedback signal in real time and send it to the external control circuit, so that the external control circuit performs the illuminating power of the laser according to the power feedback signal. Control adjustment to ensure the stability of the luminous power of the optical signal generation module.
  • the temperature detector of the tunable laser device can also detect the working temperature of the laser, and can generate a corresponding temperature feedback signal in real time and send it to the external control circuit, so that the external control circuit can work on the operating temperature of the laser according to the temperature feedback signal. Control adjustments are made so that it can operate accurately at the required temperature to accurately obtain the laser signal of the desired wavelength.
  • the wavelength-adjustable laser output method controls the operating temperature of the tunable laser device, changes the peak wavelength of the multi-longitudinal mode optical signal by temperature, and processes the single-frequency optical signal corresponding to the frequency to lock the laser
  • the operating frequency which achieves a simple, low-cost, tunable wavelength optical signal output with a wavelength range that satisfies the C-band and L-band recommendations of the International Telecommunication Union Telecommunication Standardization Organization (ITU-T), or any other The required wavelength range and wavelength spacing.
  • the embodiment of the invention further provides a tunable laser device for implementing the above-mentioned wavelength-adjustable laser output method.
  • the tunable laser device includes: a thermoelectric cooler 509, an IL-FP laser 501, a filter 503, a mirror 504, and an output fiber 508;
  • thermoelectric cooler 509 configured to adjust an operating temperature of the laser according to the received control signal
  • control signal may be a direct current signal.
  • the thermoelectric cooler 509 By loading a certain current at both ends of the thermoelectric cooler 509, heat flows from one end of the thermoelectric cooler to the other end. Conversely, if the thermoelectric cooler 509 is reversed In the direction of the current, heat flows in the opposite direction to achieve heating or cooling.
  • the thermoelectric cooler 509 can be precisely controlled to lower the temperature at one end and the temperature at the other end, or vice versa.
  • the IL-FP laser 501 is mounted and fixed on the thermoelectric cooler 509, so that it is possible to control the change of the temperature of the thermoelectric cooler 509 by heating or cooling by loading electric signals of different directions and sizes, thereby changing the IL-fixedly mounted thereto. The operating temperature of the FP laser.
  • An IL-FP laser 501 configured to excite a multi-longitudinal mode optical signal corresponding to a current operating temperature, and the multi-longitudinal mode optical signal corresponds to a transmission peak of the filter at a peak wavelength;
  • the IL-FP laser 501 receives a driving signal sent by an external circuit and is excited by the driving signal to emit a plurality of longitudinal mode optical signals.
  • the IL-FP laser 501 has a characteristic of emitting a spectrum of different multi-longitudinal mode optical signals depending on the operating temperature, that is, in the case where the IL-FP laser 501 receives the operating temperature provided by the thermoelectric cooler 509, IL The FP laser 501 is different in that the multi-longitudinal mode optical signals generated by the excitation of the same current signal are different.
  • the operating temperature of the IL-FP laser 501 is the first temperature
  • the IL-FP laser 501 generates a first multi-longitudinal mode optical signal
  • the operating temperature of the IL-FP laser 501 is the second temperature
  • IL- The FP laser 501 generates a second plurality of longitudinal mode optical signals.
  • the peak wavelengths of the first plurality of longitudinal mode optical signals and the second plurality of longitudinal mode optical signals are different.
  • the IL-FP laser 501 is composed of a rear end coating 601, a cavity 602, and a front end reflecting film 603.
  • the rear end coating 601 is a high reflection film
  • the front end reflection film 603 is a partial reflection film to facilitate the output of most of the light, and at the same time, the resonant cavity 602 can form a free oscillation of the IL-FP laser 501;
  • the IL-FP laser 501 can be customized by the above implementation method.
  • a filter 503 configured to filter the multi-longitudinal mode optical signal to obtain a single-frequency optical signal corresponding to the peak wavelength frequency
  • the filter 503 is fixedly mounted on the thermoelectric cooler 509, receives the multi-longitudinal mode optical signal transmitted by the IL-FP laser 501, and filters the multi-longitudinal mode optical signal to be processed into a single-frequency optical signal.
  • the center wavelength of the single-frequency optical signal has a corresponding relationship with the peak wavelength of the multi-longitudinal mode optical signal.
  • the center wavelength of the single-frequency optical signal generated by filtering the multi-longitudinal mode optical signal can also be changed.
  • the filter 503 employs a Fabry Perot etalon filter, and the specific implementation includes a solid chamber and an air chamber.
  • the filter 503 is a solid cavity BrillouE etalon filter, including: reflective surfaces 701 and 703, a resonant cavity 702, a thermistor 704, and a heating resistor 705.
  • Both reflective surfaces 701 and 703 are highly reflective films
  • the thermistor 704 is used to detect the operating temperature of the filter 503 and feed back to an external control circuit for temperature control;
  • the heating resistor 705 is used to heat the cavity material of the filter 503 to maintain its temperature stability. It can be bonded to the appropriate position of the filter 503 using a common power resistor, or directly in the cavity by a thin film evaporation process. A resistive film is formed on the bulk material.
  • filter 503 is an air cavity BrillouE etalon filter comprising: reflective surfaces 810 and 820 and substrate material 830 on which reflective surfaces 810 and 820 are mounted.
  • the two reflecting surfaces 810 and 820 of the cavity are composed of two identical emissive coating sheets. It is obtained by performing a coating treatment on a material such as silicon dioxide (silver glass) or silicon, wherein the film layers 811 and 821 are anti-reflection films; and the film layers 812 and 822 are high-reflection films;
  • the filter 503 can be customized as needed by the implementation described above.
  • the tunable laser device further includes a first collimating lens 502 disposed between the IL-FP laser 501 and the filter 503. For collimating and focusing a multi-longitudinal mode optical signal to maintain the collimation of the beam of the multi-longitudinal mode optical signal propagating between the IL-FP laser and the filter.
  • a mirror 504 configured to reflect a portion of the single-frequency optical signal back to the laser 401;
  • the mirror 504 is a partial mirror disposed perpendicular to the incident direction of the single-frequency optical signal, and is fixedly mounted on the thermoelectric cooler 509, and the single frequency is filtered from the IL-FP laser 501 and filtered by the filter 503.
  • the optical signal is partially reflected and injected into the IL-FP laser 501.
  • the IL-FP laser 501 is further configured to generate and output a frequency-locked optical signal having the same wavelength as the center wavelength of the single-frequency optical signal according to the center wavelength of the received single-frequency optical signal.
  • the IL-FP laser 501 enters the injection locking mode according to the received partial single-frequency optical signal, and locks its operating frequency to the same frequency as the injected light. That is, the IL-FP laser 501 emits a frequency-locked optical signal having the same center wavelength as that of the reflected partial single-frequency optical signal.
  • the locked frequency optical signal passes through the first collimating lens 502, the filter 503, the partial mirror 504, and the second collimating lens 506, and enters the output fiber 508.
  • the second collimating lens 506 is fixed on the thermoelectric cooler 509 and disposed between the partial mirror 504 and the output fiber 508 for collimating and focusing the frequency-locked optical signal into the output fiber 508.
  • the output fiber 508 is configured to receive the frequency-locked optical signal generated by the IL-FP laser 501, and transmit the frequency-locked optical signal to an optical fiber.
  • the output fiber 508 is fixed on the thermoelectric cooler 509 through the fixing clip 507, and is aligned with the output optical path of the second collimating lens 506, thereby transmitting the frequency-locked optical signal to the outside through the output fiber 508.
  • the IL-FP laser 501 When the thermoelectric cooler 509 controls the operating temperature of the IL-FP laser 501 at the first temperature, the IL-FP laser 501 generates a first multi-longitudinal mode optical signal.
  • the first collimating lens 502 is collimated and focused to the filter 503, and the filter 503 filters the first multi-longitudinal mode optical signal to be processed as a single-frequency optical signal having a central wavelength of the first wavelength, and is reflected by the partial mirror 504.
  • the IL-FP laser 501 is returned to lock its operating frequency at a first frequency corresponding to the first wavelength.
  • the injection-locked IL-FP laser 501 emits a frequency-locked optical signal having a center wavelength of a first wavelength.
  • the locked-frequency optical signal passes through the first collimating lens 502, the filter 503, the partial mirror 504, and the second collimating lens 506, and then enters the output fiber 508 for transmission.
  • the operating temperature of the thermoelectric cooler 509 is changed from the first temperature to the second temperature, and the multi-longitudinal mode optical signal generated by the IL-FP laser 501 is composed of the first multi-longitudinal mode light.
  • the signal is changed to a second multi-longitudinal mode optical signal having a central wavelength that is different from the first multi-longitudinal mode optical signal.
  • the second plurality of longitudinal mode optical signals are collimated and focused by the first collimating lens 502 to the filter 503, and the filter 503 filters the second plurality of longitudinal mode optical signals to be processed into a second single frequency having a central wavelength of the second wavelength.
  • the optical signal is reflected back to the IL-FP laser 501 via the partial mirror 504, and its operating frequency is locked to a second frequency corresponding to the second wavelength.
  • the injection-locked IL-FP laser 501 emits a frequency-locked optical signal having a center wavelength of a second wavelength.
  • the locked-frequency optical signal passes through the first collimating lens 502, the filter 503, the partial mirror 504, and the second collimating lens 506, and then enters the output fiber 508 for transmission. Thereby, the output wavelength of the tunable laser device is changed from the first wavelength to the second wavelength, and the laser signal output of the tunable wavelength is realized.
  • the tunable laser device provided by the embodiment of the present invention further includes a backlight detector 511 fixedly mounted on the thermoelectric cooler 509 and disposed on the opposite side of the illumination direction of the IL-FP laser 501 for detecting the
  • the illumination power of the IL-FP laser 501 can be generated in real time to generate a corresponding power feedback signal to the external control circuit, so that the external control circuit can control the illumination power of the IL-FP laser 501 according to the power feedback signal to ensure the IL-FP laser.
  • the tunable laser device provided by the embodiment of the present invention further includes a temperature detector 510 fixedly mounted on the thermoelectric cooler 509, disposed adjacent to the IL-FP laser 501, for detecting the operation of the IL-FP laser 501.
  • a temperature detector 510 fixedly mounted on the thermoelectric cooler 509, disposed adjacent to the IL-FP laser 501, for detecting the operation of the IL-FP laser 501.
  • the corresponding temperature feedback signal can be generated in real time and sent to the external control circuit, so that the external control circuit can control the operating temperature of the IL-FP laser 501 according to the temperature feedback signal, so that it can accurately operate at the required temperature.
  • the laser signal of the desired wavelength is accurately obtained.
  • the tunable laser device provided by the embodiment of the present invention further includes an optical isolator 505 fixedly mounted on the thermoelectric cooler 509 and disposed between the partial mirror 504 and the second collimating lens 506 for blocking the external Other optical signals enter the IL-FP laser 501 through the optical isolator 504, affecting the locked operating state of the IL-FP laser 501.
  • an optical isolator 505 fixedly mounted on the thermoelectric cooler 509 and disposed between the partial mirror 504 and the second collimating lens 506 for blocking the external Other optical signals enter the IL-FP laser 501 through the optical isolator 504, affecting the locked operating state of the IL-FP laser 501.
  • the tunable laser device changes the peak wavelength of the multi-longitudinal mode optical signal generated by the laser by controlling the operating temperature of the IL-FP laser, and processes the single-frequency optical signal corresponding to the peak wavelength frequency for use. Locking the working frequency of the laser, causing the laser to generate the frequency-locked optical signal output of the corresponding frequency, realizing a simple, low-cost, adjustable laser device with adjustable wavelength optical signal output, the output wavelength range can meet the coverage of international telecommunications The C-band and L-band recommended by the Alliance Telecommunications Standardization Organization (ITU-T), or any other desired wavelength range and wavelength spacing.
  • ITU-T Alliance Telecommunications Standardization Organization

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Abstract

一种波长可调的激光输出方法和可调激光装置，所述方法包括：热电制冷器（509）根据接收到的控制信号调节激光器（501）的工作温度，从而使激光器（501）激发出当前工作温度所对应的多纵模光信号，并且使多纵模光信号在峰值波长处与滤波器（503）的透射峰值相对应；滤波器（503）将多纵模光信号进行滤波处理，得到与峰值波长频率相应的单频光信号；反射镜（504）将单频光信号的部分反射回所述激光器（501）；激光器（501）根据接收到的单频光信号的中心波长锁定工作频率，生成与单频光信号的中心波长相同波长的锁频光信号并输出。通过温度改变多纵模光信号的峰值波长并处理为与之频率相应的单频光信号，锁定激光器的工作频率，实现了简单、低成本的可调波长的光信号输出。

Description

波长可调的激光输出方法和可调激光装置 本申请要求于 2013年 5月 31日提交中国专利局、 申请号为 201310211285. 9、发明 名称为 "波长可调的激光输出方法和可调激光装置"的中国专利申请的优先权， 其全部 内容通过引用结合在本申请中。 技术领域 本发明涉及光通信技术领域，尤其涉及一种波长可调的激光输出方法和可调波长的 激光装置。 背景技术 在密集波分复用系统（DWDM) 以及其他一些光通信领域， 需要用到对波长可以进行 调节的激光光源， 以便实现网络节点的灵活配置以及波长的重新调度。 目前常用的可调 激光器主要有： 取样光栅分布式布拉格反射器激光器 （SG-DBR laser ) , 外腔激光器 ( External Cavity Tunable Laser-Tunable ECL) 以及分布反馈式激光器阵列可调激 光器 （DFB Laser Array) 等。 但这些可调激光器的设计大都比较复杂， 价格较高， 阻 碍了该技术在网络设备中的应用范围， 特别是在短距城域的波分复用网络中的应用。 发明内容
本发明实施例提供了一种波长可调的激光输出方法和可调激光装置，可以实现一种 简单低成本的波长可调的激光输出方法， 通过改变可调激光装置的工作温度， 即可以可 控制方式改变多纵模光信号的中心波长， 从而实现了简单、 低成本的可调波长的光信号 输出。
第一方面， 本发明实施例提供了一种波长可调的激光输出方法， 所述方法包括： 热电制冷器根据接收到的控制信号调节激光器的工作温度， 从而使激光器激发出当 前工作温度所对应的多纵模光信号， 并且使所述多纵模光信号在峰值波长处与滤波器的 透射峰值相对应；
滤波器将所述多纵模光信号进行滤波处理，得到与所述峰值波长频率相应的单频光 信号；
反射镜将所述单频光信号的部分反射回所述激光器； 所述激光器根据接收到的所述单频光信号的中心波长锁定工作频率， 生成与所述单 频光信号的中心波长相同波长的锁频光信号并输出。
在第一种可能的实现方式中， 所述热电制冷器根据接收到的控制信号， 调节激光器 的工作温度， 从而使激光器激发出当前工作温度所对应的多纵模光信号， 并且使所述多 纵模光信号在峰值波长处与滤波器的透射峰值相对应具体包括：
当所述控制信号为第一控制信号时， 热电制冷器根据接收到的第一控制信号， 调节 激光器的工作温度为第一温度， 从而使激光器激发出第一工作温度所对应的第一多纵模 光信号， 并且使所述第一多纵模光信号在第一峰值波长处与滤波器的一个透射峰值相对 应；
当所述控制信号为第二控制信号时， 热电制冷器根据接收到的第二控制信号， 调节 激光器的工作温度为第二温度， 从而使激光器激发出第二工作温度所对应的第二多纵模 光信号， 并且使所述第二多纵模光信号在第二峰值波长处与滤波器的另一个透射峰值相 对应；
其中， 所述第一温度和第二温度均在所述激光器的允许工作温度范围内； 当所述第 一温度不等于所述第二温度时， 所述第一峰值波长与所述第二峰值波长不相同。
在第二种可能的实现方式中， 所述方法还包括：
背光检测器检测所述激光器的发光功率， 生成相应的功率反馈信号发送给外部控制 电路， 用以控制稳定所述激光器的发光功率， 产生峰值波长恒定的多纵模光信号。
在第三种可能的实现方式中， 所述方法还包括：
温度探测器检测所述激光器的工作温度， 生成相应的温度反馈信号， 用以所述激光 器根据所述温度反馈信号生成相应的调温信号， 调整所述激光器的工作温度。
第二方面， 本发明实施例提供了一种可调激光装置， 包括： 热电制冷器、 激光器、 滤波器、 反射镜；
热电制冷器， 用于根据接收到的控制信号调节激光器的工作温度；
激光器， 用于激发出当前工作温度所对应的多纵模光信号， 并且所述多纵模光信号 在峰值波长处与滤波器的透射峰值相对应；
滤波器， 用于将所述多纵模光信号进行滤波处理， 得到与所述峰值波长频率相应的 单频光信号；
反射镜， 用于将所述单频光信号的部分反射回所述激光器； 所述激光器还用于根据接收到的所述单频光信号的中心波长锁定工作频率， 生成与 所述单频光信号的中心波长相同波长的锁频光信号并输出。
在第一种可能的实现方式中， 所述热电制冷器具体用于：
当所述控制信号为第一控制信号时， 热电制冷器根据接收到的第一控制信号， 调节 激光器的工作温度为第一温度， 从而使激光器激发出第一工作温度所对应的第一多纵模 光信号， 并且使所述第一多纵模光信号在第一峰值波长处与滤波器的一个透射峰值相对 应；
当所述控制信号为第二控制信号时， 热电制冷器根据接收到的第二控制信号， 调节 激光器的工作温度为第二温度， 从而使激光器激发出第二工作温度所对应的第二多纵模 光信号， 并且使所述第二多纵模光信号在第二峰值波长处与滤波器的另一个透射峰值相 对应； 其中， 所述第一温度和第二温度均在所述激光器的允许工作温度范围内； 当所述 第一温度不等于所述第二温度时， 所述第一峰值波长与所述第二峰值波长不相同。
在第二种可能的实现方式中， 所述装置还包括背光检测器， 用于检测所述激光器的 发光功率， 生成相应的功率反馈信号发送给外部控制电路， 用以控制稳定所述激光器的 发光功率， 产生峰值波长恒定的多纵模光信号。
在第三种可能的实现方式中， 所述装置还包括温度探测器， 用于检测所述激光器的 工作温度， 生成相应的调温信号； 所述调温信号用以调整所述激光器的工作温度。
在第四种可能的实现方式中， 所述装置还包括光隔离器， 用于阻止光信号通过所述 光隔离器进入所述激光器。
在第五种可能的实现方式中， 所述激光器、 滤波器和反射镜固定安装于所述热电制 冷器上。
本发明实施例的波长可调的激光输出方法和可调激光装置，通过控制温度改变激光 器产生的多纵模光信号的峰值波长， 并处理为与峰值波长频率相应的单频光信号， 用以 锁定激光器的工作频率， 使激光器产生相应频率的锁频光信号输出， 实现了简单、 低成 本的可调波长的光信号输出。 附图说明 图 1为本发明实施例提供的一种波长可调的激光输出方法的流程图；
图 2为本发明实施例提供的一种波长可调的激光输出方法的光谱特性示意图之- 图 3为本发明实施例提供的一种 IL-FP激光器的锁定示意图； 图 4为本发明实施例提供的一种波长可调的激光输出方法的光谱特性示意图之二; 图 5为本发明实施例提供的一种可调激光装置的示意图；
图 6为本发明实施例提供的一种 IL-FP激光器的示意图；
图 7为本发明实施例提供的一种滤波器的示意图；
图 8为本发明实施例提供的另一种滤波器的示意图。
下面通过附图和实施例， 对本发明实施例的技术方案做进一步的详细描述。 具体实施方式 图 1为本发明实施例提供的一种波长可调的激光输出方法的流程图。 如图 1所示， 波 长可调的激光输出方法包括如下步骤：
步骤 110， 热电制冷器根据接收到的控制信号调节激光器的工作温度， 从而使激光 器激发出当前工作温度所对应的多纵模光信号， 并且使所述多纵模光信号在峰值波长处 与滤波器的透射峰值相对应；
具体的， 外部控制电路向可调激光装置发送控制信号， 其中控制信号可以是直流电 信号， 被可调激光装置的热电制冷器所接收， 可调激光装置的热电制冷器根据控制信号 对其自身温度进行控制调整， 使其在与可调激光装置的激光器一端的温度信号发生相应 变化， 根据控制信号调整升高或降低温度。 激光器在当前的工作温度下， 接收外部发送 的电流信号， 并由电流信号激发， 发射出多纵模光信号， 并且控制信号控制调节的温度 能够使多纵模光信号在峰值波长处与滤波器的透射峰值相对应。 在一个具体的例子中， 该多纵模光信号的光谱特性如图 2中 B图所示， 滤波器的透射峰值 -频率特性曲线如图 2中 A图所示。 可以看到， 在这个具体的例子中， 多纵模光信号的峰值波长位置与滤波器的 一个透射峰值是相对应的。 其中， 激光器优选为 IL-FP激光器。
在激光器发射出多纵模光信号之后， 对该多纵模光信号进行准直和聚焦， 以维持该 多纵模光信号在可调激光装置的激光器和滤波器之间传播的光束的准直性， 使多纵模光 信号能够准确的传输至滤波器。
步骤 120， 滤波器将所述多纵模光信号进行滤波处理， 得到与所述峰值波长频率相 应的单频光信号；
具体的， 滤波器接收到多纵模光信号， 并对其进行滤波处理， 将多纵模光信号滤波 处理为单频光信号。 在上述的具体例子中， 如图 2中 B图中所示的第一多纵模光信号经过 该滤波处理后得到图 2中 C图中所示的光谱特性的单频光信号。 步骤 130， 反射镜将所述单频光信号的部分反射回所述激光器；
具体的， 滤波后的单频光信号经过反射镜的部分反射， 通过原光路返回到激光器， 形成激光器的注入光。
步骤 140， 所述激光器根据接收到的所述单频光信号的中心波长锁定工作频率， 生 成与所述单频光信号的中心波长相同波长的锁频光信号并输出。
具体的， IL-FP激光器具有注入锁定的特性， 由此工作在注入锁定模式， 并发射出 与部分反射后的单频光信号中心波长相同波长的锁频光信号。 其光谱特性如图 3所示。 其中， 中心波长是指在波长范围内光谱发光强度或者辐射功率能量最大处所对应的波 长。
在生成锁频光信号之后， 该方法还包括将锁频光信号准直聚焦， 使锁频光信号能够 准确传输至可调激光装置的输出光纤内， 并通过输出光纤对该锁频光信号进行传输， 从 而可调激光装置向外部提供一定中心波长的单频率的激光信号。该锁频光信号的中心波 长与前述步骤 130中的单频光信号的中心波长是相同的， 而单频光信号的中心波长是由 当前工作温度下的激光器产生的多纵模光信号经过滤波得到的。 因此， 可以通过上述方 法，在一定的工作温度下根据激光器产生的多纵模光信号经过滤波处理获得与多纵模光 信号的峰值波长相应频率的单一频率的锁频光信号输出。
上述实施例对可调激光装置的工作原理进行了说明， 下面结合图 4， 对可调激光装 置的波长调节原理进行说明。
当控制信号为第一控制信号时， 热电制冷器根据接收到的第一控制信号， 调节激光 器的工作温度为第一温度， 从而使激光器激发出第一工作温度所对应的第一多纵模光信 号，并且使第一多纵模光信号在第一峰值波长处与滤波器的一个透射峰值相对应；其中， 所述第一温度在所述激光器的允许工作温度范围内。 在一个例子中， 第一多纵模光信号 的光谱特性如图 4中 B图实线部分所示， 滤波器的透射峰值 -频率特性曲线如图 4中 A图所 示。可以看到，第一多纵模光信号的第一峰值波长与滤波器的一个透射峰值是相对应的。
滤波器将第一多纵模光信号进行滤波处理，得到与第一峰值波长频率相应的第一单 频光信号； 反射镜将第一单频光信号的部分反射回激光器， 激光器根据接收到的第一单 频光信号的中心波长锁定其工作频率， 生成与第一单频光信号的中心波长相同波长的第 一锁频光信号并输出。 其中， 第一锁频光信号如图 4中 C图实线部分所示。
当控制信号发生改变时， 由第一控制信号改变为第二控制信号， 热电制冷器根据接 收到的第二控制信号， 调节激光器的工作温度为第二温度， 从而使激光器激发出第二工 作温度所对应的第二多纵模光信号， 并且使第二多纵模光信号在第二峰值波长处与滤波 器的另一个透射峰值相对应； 其中， 第二温度也在所述激光器的允许工作温度范围内， 并且， 当第一温度不等于第二温度时， 第一峰值波长与第二峰值波长不相同。 在这个例 子中， 第二多纵模光信号的光谱特性如图 4中 B图虚线部分所示， 滤波器的透射峰值-频 率特性曲线还如图 4中 A图所示。 可以看到， 第二多纵模光信号的第二峰值波长与滤波器 的另一个透射峰值是相对应的。 并且， 第二峰值波长与第一峰值波长不同， 第一峰值波 长与第二峰值波长对应的滤波器的透射峰值也不同。 由此可知， 控制信号控制的温度的 变化导致了激光器产生的多纵模光信号在峰值波长 （即频率） 上发生了变化。
滤波器将第二多纵模光信号进行滤波处理，得到与第二峰值波长频率相应的第二单 频光信号； 反射镜将第二单频光信号的部分反射回激光器， 激光器根据接收到的第二单 频光信号的中心波长锁定其工作频率， 生成与第二单频光信号的中心波长相同波长的第 二锁频光信号并输出。 其中， 第二锁频光信号如图 4中 C图虚线部分所示。
因为激光器在不同的工作温度下， 产生的多纵模光信号的峰值波长（即上述第一峰 值波长与第二峰值波长） 的频率是不同的， 因此基于第一峰值波长产生的第一单频光信 号与基于第二峰值波长产生的第二单频光信号的频率也是不同的， 由第二单频光信号注 入锁定的激光器产生的第二锁频光信号的波长（即频率） 与第一锁频光信号的波长（即 频率） 也是不同的。 由此可以通过控制改变激光器的工作温度， 实现可调波长的光信号 输出。
优选的， 可调激光装置的背光检测器还可以对激光器的发光功率进行检测， 可以实 时的生成相应的功率反馈信号发送给外部控制电路， 以便外部控制电路根据功率反馈信 号对激光器的发光功率进行控制调整， 保证光信号生成模块的发光功率稳定性。
优选的， 可调激光装置的温度探测器还可以对激光器的工作温度进行检测， 可以实 时的生成相应的温度反馈信号并发送给外部控制电路， 以便外部控制电路根据温度反馈 信号对激光器的工作温度进行控制调整， 使其能够准确的工作在所要求的温度下， 从而 精确地获得需要波长的激光信号。
本发明实施例提供的波长可调的激光输出方法， 通过控制可调激光装置的工作温 度， 通过温度改变多纵模光信号的峰值波长并处理为与之频率相应的单频光信号， 锁定 激光器的工作频率， ， 实现了简单、 低成本的可调波长的光信号输出， 其波长范围可以 满足覆盖国际电信联盟远程通信标准化组织（ITU-T)建议的 C波段以及 L波段， 或其他任 意所需要的波长范围和波长间隔。 相应的， 本发明实施例还提供了一种可调激光装置， 用以实现上述波长可调的激光 输出方法。 如图 5所示， 可调激光装置包括： 热电制冷器 509、 IL-FP激光器 501、 滤波器 503、 反射镜 504和输出光纤 508;
热电制冷器 509， 用于根据接收到的控制信号调节激光器的工作温度；
具体的， 该控制信号可以是直流电信号， 通过在热电制冷器 509的两端加载一定的 电流， 热量就会从热电制冷器的一端流到另一端， 相反地， 如果给热电制冷器 509加相 反方向的电流， 热量就会从相反方向流动， 从而实现加热或制冷。 热电制冷器 509可以 精确控制使一端的温度降低， 另一端的温度升高， 或反之。 IL-FP激光器 501安装固定在 热电制冷器 509上， 因此可以通过加载不同方向及大小的电信号来控制改变热电制冷器 509的温度是加热或者是制冷， 从而改变与之相固定安装的 IL-FP激光器的工作温度。
IL-FP激光器 501， 用于激发出当前工作温度所对应的多纵模光信号， 并且所述多纵 模光信号在峰值波长处与滤波器的透射峰值相对应；
具体的， IL-FP激光器 501接收外部电路发送的驱动信号， 并由驱动信号激发， 发射 出多纵模光信号。
IL-FP激光器 501具有会根据工作温度的不同而发出不同的多纵模光信号的光谱的 特性， 即在 IL-FP激光器 501接收到热电制冷器 509提供的工作温度不相同的情况下， IL-FP激光器 501由相同电流信号激发产生的多纵模光信号是不同的。在 IL-FP激光器 501 的工作温度为第一温度的情况下， IL-FP激光器 501产生第一多纵模光信号， 在 IL-FP激 光器 501的工作温度为第二温度的情况下， IL-FP激光器 501产生第二多纵模光信号。 当 第一温度与第二温度不相同时， 上述第一多纵模光信号与第二多纵模光信号的峰值波长 不相同。
在一个具体的例子中， 如图 6所示， IL-FP激光器 501由后端面镀膜 601， 谐振腔 602 和前端面反射膜 603构成。 其中后端面镀膜 601为高反射膜， 前端面反射膜 603为部分反 射膜， 以方便大部份光能够输出， 同时又能构成谐振腔 602形成 IL-FP激光器 501的自由 振荡；
谐振腔 602的长度根据需要的频率间隔来决定， 比如需要 100G的频率间隔， 可根据 公式 A f= C/2nL计算出。 其中， f为光信号的频率， C为光速， A f为不同谐振模式的频 率间隔。
谐振腔长度 L= C/2n Δ f =2. 99792458 X 108/( 2 Xn X 100 X 109) = 1. 49896229/n (mm) ; 其中， n为构成谐振腔的半导体材料的折射率。 IL-FP激光器 501可以通过上述实现方法进行定制。
滤波器 503， 用于将所述多纵模光信号进行滤波处理， 得到与所述峰值波长频率相 应的单频光信号； ；
具体的， 滤波器 503固定安装于热电制冷器 509之上， 接收 IL-FP激光器 501发送的多 纵模光信号， 对该多纵模光信号进行滤波， 处理为单频光信号。 该单频光信号的中心波 长与多纵模光信号的峰值波长具有对应关系， 当热电制冷器 509根据接收的控制信号控 制改变 IL-FP激光器 501的工作温度时， 单频光信号的中心波长也会随之发生改变。
此外， 通过改变滤波器 503的器件参数， 也可以改变多纵模光信号滤波后生成的单 频光信号的中心波长。
优选的， 滤波器 503采用法布里珀罗标准具滤波器， 其具体实现方式包括固体腔和 空气腔两种。
在一个具体的例子中， 如图 7所示， 滤波器 503为固体腔布里珀罗标准具滤波器， 包 括： 反射面 701和 703、 谐振腔 702、 热敏电阻 704和加热电阻 705。
两个反射面 701和 703均为高反射膜；
谐振腔 702由固体透光的材料制作， 比如二氧化硅 （石英玻璃） 、 硅等材料； 谐振腔 702的长度根据需要的滤波器自由程 （FSR) 决定， 比如需要 100G FSR间隔， 可根据公式 A f= C/2nL计算出。 其中 f为光信号的频率， C为光速， A f为不同谐振模式 的频率间隔。 谐振腔长度 L= C/2n Δ f =2. 99792458 X 108/ ( 2 X n X 100 X 109) =
1. 49896229/n (mm) ； 式中 n为构成谐振腔的材料的折射率。
热敏电阻 704用于检测滤波器 503的工作温度并反馈给外部的控制电路进行温度控 制；
加热电阻 705用来对滤波器 503的腔体材料进行加热， 以维持其温度的稳定， 它可以 使用普通的功率电阻粘接在滤波器 503的适当位置， 也可以通过薄膜蒸镀工艺直接在腔 体材料上制作电阻膜。
在另一个具体的例子中， 如图 8所示， 滤波器 503为空气腔布里珀罗标准具滤波器， 包括： 反射面 810和 820以及安装反射面 810和 820的衬底材料 830。
谐振腔的两个反射面 810和 820由两个相同的发射镀膜片构成。 通过在二氧化硅（石 英玻璃） 或硅等材料上进行镀膜处理来获得， 其中膜层 811和 821为防反射膜； 膜层 812 和 822为高反射膜；
830为安装这两个反射面 810和 820的衬底材料， 可以使用陶磁或者石英玻璃制成。 按照前述的计算公式 L= C/2n A f， 由于空气的折射率 n=l， 因此， 例如当需要的自 由程 FSR=100GHz时， 腔长 L=2. 99792458 X 107 ( 2 X 100 X 109) = 1. 49896229 (mm) 。
滤波器 503可以根据需要通过上述的实现方法进行定制。
为保证 IL-FP激光器 501发送的多纵模光信号能够准确的传输至滤波器 503， 可调激 光装置还包括第一准直透镜 502， 设置于 IL-FP激光器 501与滤波器 503之间， 用于对多纵 模光信号进行准直和聚焦， 以维持所述多纵模光信号在所述 IL-FP激光器和所述滤波器 之间传播的光束的准直性。
反射镜 504， 用于将所述单频光信号的部分反射回所述激光器 401 ; ；
具体的， 反射镜 504为部分反射镜， 垂直于单频光信号射入方向设置， 固定安装于 热电制冷器 509之上，将来自于 IL-FP激光器 501并经由滤波器 503滤波后的单频光信号部 分反射注入到 IL-FP激光器 501中。
IL-FP激光器 501还用于根据接收到的单频光信号的中心波长锁定工作频率， 生成与 单频光信号的中心波长相同波长的锁频光信号并输出。
具体的， IL-FP激光器 501根据接收到注入的部分单频光信号进入注入锁定工作模 式， 将其工作频率锁定在与注入光相同的频率上。 即 IL-FP激光器 501发射出与反射后的 部分单频光信号中心波长相同的锁频光信号。
锁频光信号经过第一准直透镜 502、 滤波器 503、 部分反射镜 504和第二准直透镜 506 后进入输出光纤 508。 其中， 第二准直透镜 506固定在热电制冷器 509之上， 设置于部分 反射镜 504与输出光纤 508之间， 用于将锁频光信号准直聚焦传输到输出光纤 508内。
输出光纤 508， 用于接收所述 IL-FP激光器 501生成的所述锁频光信号， 将所述锁频 光信号进行光纤传输。
具体的， 输出光纤 508通过固定夹 507固定在热电制冷器 509之上， 与第二准直透镜 506的输出光路对准， 从而将锁频光信号通过输出光纤 508向外传输。
当热电制冷器 509控制 IL-FP激光器 501的工作温度在第一温度时， IL-FP激光器 501 产生第一多纵模光信号。 经过第一准直透镜 502准直聚焦传输至滤波器 503， 滤波器 503 对第一多纵模光信号进行滤波， 处理为中心波长为第一波长的单频光信号， 经部分反射 镜 504反射回 IL-FP激光器 501， 将其工作频率锁定在与第一波长相对应的第一频率上。 经注入锁定后的 IL-FP激光器 501发射出中心波长为第一波长的锁频光信号。锁频光信号 经过第一准直透镜 502、 滤波器 503、 部分反射镜 504和第二准直透镜 506后进入输出光纤 508向外传输。 当需要改变可调激光装置的工作波长时， 将热电制冷器 509的工作温度由当第一温 度改变为第二温度， IL-FP激光器 501产生的多纵模光信号由第一多纵模光信号改变为中 心波长与第一多纵模光信号不相同的第二多纵模光信号。第二多纵模光信号经过第一准 直透镜 502准直聚焦传输至滤波器 503， 滤波器 503对第二多纵模光信号进行滤波， 处理 为中心波长为第二波长的第二单频光信号， 经部分反射镜 504反射回 IL-FP激光器 501， 将其工作频率锁定在与第二波长相对应的第二频率上。经注入锁定后的 IL-FP激光器 501 发射出中心波长为第二波长的锁频光信号。 锁频光信号经过第一准直透镜 502、 滤波器 503、 部分反射镜 504和第二准直透镜 506后进入输出光纤 508向外传输。 由此实现了可调 激光装置的输出波长由第一波长改变为第二波长， 实现了可调波长的激光信号输出。
优选的， 本发明实施例提供的可调激光装置还包括背光检测器 511， 固定安装于热 电制冷器 509之上， 设置于 IL-FP激光器 501发光方向的反方向一侧， 用于检测所述 IL-FP 激光器 501的发光功率， 可以实时的生成相应的功率反馈信号发送给外部控制电路， 以 便外部控制电路根据功率反馈信号对 IL-FP激光器 501的发光功率进行控制调整， 保证 IL-FP激光器 501的发光功率稳定性。
优选的， 本发明实施例提供的可调激光装置还包括温度探测器 510， 固定安装于热 电制冷器 509之上， 紧邻 IL-FP激光器 501设置， 用于检测所述 IL-FP激光器 501的工作温 度， 可以实时的生成相应的温度反馈信号并发送给外部控制电路， 以便外部控制电路根 据温度反馈信号对 IL-FP激光器 501的工作温度进行控制调整， 使其能够准确的工作在所 要求的温度下， 从而精确地获得需要波长的激光信号。
优选的， 本发明实施例提供的可调激光装置还包括光隔离器 505， 固定安装于热电 制冷器 509之上， 设置于部分反射镜 504与第二准直透镜 506之间， 用于阻止外部其他光 信号通过光隔离器 504进入 IL-FP激光器 501， 影响 IL-FP激光器 501的锁定工作状态。
本发明实施例提供的可调激光装置， 通过控制 IL-FP激光器的工作温度， 改变激光 器产生的多纵模光信号的峰值波长， 并处理为与峰值波长频率相应的单频光信号， 用以 锁定激光器的工作频率， 使激光器产生相应频率的锁频光信号输出， 实现了一种简单、 低成本、 具有可调波长的光信号输出的可调激光装置， 其输出波长范围可以满足覆盖国 际电信联盟远程通信标准化组织（ITU-T)建议的 C波段以及 L波段， 或其他任意所需要的 波长范围和波长间隔。
以上所述的具体实施方式， 对本发明的目的、 技术方案和有益效果进行了进一步详 细说明， 所应理解的是， 以上所述仅为本发明的具体实施方式而已， 并不用于限定本发 明的保护范围， 凡在本发明的精神和原则之内， 所做的任何修改、 等同替换、 改进等， 均应包含在本发明的保护范围之内。

Claims

权利要求
1、 一种波长可调的激光输出方法， 其特征在于， 所述方法包括：
热电制冷器根据接收到的控制信号调节激光器的工作温度， 从而使激光器激发出当 前工作温度所对应的多纵模光信号， 并且使所述多纵模光信号在峰值波长处与滤波器的 透射峰值相对应；
滤波器将所述多纵模光信号进行滤波处理，得到与所述峰值波长频率相应的单频光 信号；
反射镜将所述单频光信号的部分反射回所述激光器；
所述激光器根据接收到的所述单频光信号的中心波长锁定工作频率， 生成与所述单 频光信号的中心波长相同波长的锁频光信号并输出。
2、 根据权利要求 1所述的波长可调的激光输出方法， 其特征在于， 所述热电制冷器 根据接收到的控制信号， 调节激光器的工作温度， 从而使激光器激发出当前工作温度所 对应的多纵模光信号， 并且使所述多纵模光信号在峰值波长处与滤波器的透射峰值相对 应具体包括：
当所述控制信号为第一控制信号时， 热电制冷器根据接收到的第一控制信号， 调节 激光器的工作温度为第一温度， 从而使激光器激发出第一工作温度所对应的第一多纵模 光信号， 并且使所述第一多纵模光信号在第一峰值波长处与滤波器的一个透射峰值相对 应；
当所述控制信号为第二控制信号时， 热电制冷器根据接收到的第二控制信号， 调节 激光器的工作温度为第二温度， 从而使激光器激发出第二工作温度所对应的第二多纵模 光信号， 并且使所述第二多纵模光信号在第二峰值波长处与滤波器的另一个透射峰值相 对应；
其中， 所述第一温度和第二温度均在所述激光器的允许工作温度范围内； 当所述第 一温度不等于所述第二温度时， 所述第一峰值波长与所述第二峰值波长不相同。
3、根据权利要求 1所述的波长可调的激光输出方法，其特征在于，所述方法还包括: 背光检测器检测所述激光器的发光功率， 生成相应的功率反馈信号发送给外部控制 电路， 用以控制稳定所述激光器的发光功率， 产生峰值波长恒定的多纵模光信号。
4、根据权利要求 1所述的波长可调的激光输出方法，其特征在于，所述方法还包括: 温度探测器检测所述激光器的工作温度， 生成相应的温度反馈信号， 用以所述激光 器根据所述温度反馈信号生成相应的调温信号， 调整所述激光器的工作温度。
5、 一种可调激光装置， 其特征在于， 所述装置包括： 热电制冷器、 激光器、 滤波 器、 反射镜；
热电制冷器， 用于根据接收到的控制信号调节激光器的工作温度；
激光器， 用于激发出当前工作温度所对应的多纵模光信号， 并且所述多纵模光信号 在峰值波长处与滤波器的透射峰值相对应；
滤波器， 用于将所述多纵模光信号进行滤波处理， 得到与所述峰值波长频率相应的 单频光信号；
反射镜， 用于将所述单频光信号的部分反射回所述激光器；
所述激光器还用于根据接收到的所述单频光信号的中心波长锁定工作频率， 生成与 所述单频光信号的中心波长相同波长的锁频光信号并输出。
6、 根据权利要求 5所述的可调激光装置， 其特征在于， 所述热电制冷器具体用于： 当所述控制信号为第一控制信号时， 热电制冷器根据接收到的第一控制信号， 调节 激光器的工作温度为第一温度， 从而使激光器激发出第一工作温度所对应的第一多纵模 光信号， 并且使所述第一多纵模光信号在第一峰值波长处与滤波器的一个透射峰值相对 应；
当所述控制信号为第二控制信号时， 热电制冷器根据接收到的第二控制信号， 调节 激光器的工作温度为第二温度， 从而使激光器激发出第二工作温度所对应的第二多纵模 光信号， 并且使所述第二多纵模光信号在第二峰值波长处与滤波器的另一个透射峰值相 对应； 其中， 所述第一温度和第二温度均在所述激光器的允许工作温度范围内； 当所述 第一温度不等于所述第二温度时， 所述第一峰值波长与所述第二峰值波长不相同。
7、根据权利要求 5所述的可调激光装置，其特征在于，所述装置还包括背光检测器， 用于检测所述激光器的发光功率， 生成相应的功率反馈信号发送给外部控制电路， 用以 控制稳定所述激光器的发光功率， 产生峰值波长恒定的多纵模光信号。
8、根据权利要求 5所述的可调激光装置，其特征在于，所述装置还包括温度探测器， 用于检测所述激光器的工作温度， 生成相应的调温信号； 所述调温信号用以调整所述激 光器的工作温度。
9、 根据权利要求 5所述的可调激光装置， 其特征在于， 所述装置还包括光隔离器， 用于阻止光信号通过所述光隔离器进入所述激光器。
10、 根据权利要求 5所述的可调激光装置， 其特征在于， 所述激光器、 滤波器和反 射镜固定安装于所述热电制冷器上。
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