CN114825004A - High-speed frequency-sweeping optical fiber light source - Google Patents

High-speed frequency-sweeping optical fiber light source Download PDF

Info

Publication number
CN114825004A
CN114825004A CN202210313891.0A CN202210313891A CN114825004A CN 114825004 A CN114825004 A CN 114825004A CN 202210313891 A CN202210313891 A CN 202210313891A CN 114825004 A CN114825004 A CN 114825004A
Authority
CN
China
Prior art keywords
optical fiber
light source
pulse
laser
frequency
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202210313891.0A
Other languages
Chinese (zh)
Inventor
周勇
常艺暄
高伟清
马晓辉
方文坛
陈小林
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hefei University of Technology
Original Assignee
Hefei University of Technology
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hefei University of Technology filed Critical Hefei University of Technology
Priority to CN202210313891.0A priority Critical patent/CN114825004A/en
Publication of CN114825004A publication Critical patent/CN114825004A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • 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
    • H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
    • H01S3/06—Construction or shape of active medium
    • H01S3/063—Waveguide lasers, i.e. whereby the dimensions of the waveguide are of the order of the light wavelength
    • H01S3/067—Fibre lasers
    • H01S3/06754—Fibre amplifiers
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/01—Arrangements or apparatus for facilitating the optical investigation
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/41—Refractivity; Phase-affecting properties, e.g. optical path length
    • G01N21/45—Refractivity; Phase-affecting properties, e.g. optical path length using interferometric methods; using Schlieren methods
    • 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
    • H01S3/005—Optical devices external to the laser cavity, specially adapted for lasers, e.g. for homogenisation of the beam or for manipulating laser pulses, e.g. pulse shaping
    • 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
    • H01S3/005—Optical devices external to the laser cavity, specially adapted for lasers, e.g. for homogenisation of the beam or for manipulating laser pulses, e.g. pulse shaping
    • H01S3/0057—Temporal shaping, e.g. pulse compression, frequency chirping
    • 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
    • H01S3/11—Mode locking; Q-switching; Other giant-pulse techniques, e.g. cavity dumping
    • H01S3/1106—Mode locking
    • H01S3/1112—Passive mode locking
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/01—Arrangements or apparatus for facilitating the optical investigation
    • G01N2021/0106—General arrangement of respective parts
    • G01N2021/0112—Apparatus in one mechanical, optical or electronic block
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2201/00—Features of devices classified in G01N21/00
    • G01N2201/06—Illumination; Optics
    • G01N2201/061—Sources

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Optics & Photonics (AREA)
  • Plasma & Fusion (AREA)
  • Engineering & Computer Science (AREA)
  • General Health & Medical Sciences (AREA)
  • Biochemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Analytical Chemistry (AREA)
  • Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Lasers (AREA)

Abstract

The invention discloses a high-speed sweep frequency optical fiber light source, which comprises the following specific devices: the passive mode-locking pulse light source outputs high-repetition-frequency broad-spectrum mode-locking pulses, the dispersion transmission of the passive mode-locking pulse light source obeys a parabolic differential equation similar to one-dimensional paraxial diffraction, and is similar to Fraunhofer diffraction.

Description

High-speed frequency-sweeping optical fiber light source
Technical Field
The invention belongs to the technical field of fiber lasers, and particularly relates to a high-speed frequency-sweeping fiber light source.
Background
Optical Coherence Tomography (OCT) is a new method of high resolution cross-sectional imaging of transparent and translucent sample tissues introduced in 1991 and has been widely used in many ways in recent years, especially in the biomedical field. The swept-frequency light source is an important component in an OCT system, and has wide development space and application prospect, so that the swept-frequency light source has considerable feasibility and practical significance for research and development of high-speed swept-frequency light sources.
The main swept-frequency light sources applied to the OCT system are: the laser comprises a short cavity laser, a frequency sweeping vertical cavity surface emitting laser and a Fourier frequency domain mode-locked laser. The laser wavelength of the short-cavity laser is discrete, the coherence length is reduced along with the increase of the scanning speed, the performance of the laser is reduced by improving the scanning speed, and therefore the laser is limited to the scanning speed of hundreds of kHz. The swept-frequency vertical cavity surface emitting laser is essentially a Fabry-Perot filter with an integrated gain medium, and the maximum scanning speed of the swept-frequency vertical cavity surface emitting laser is limited by the mechanical property of a micro-electro-mechanical system driving filter; the fourier-domain mode-locked laser is a full-fiber laser whose sweep rate is limited by the tuning of the F-P tunable filter. The tuning elements in the swept-frequency VCSEL and the Fourier-domain mode-locked laser limit the resonant frequency to a level below MHz in the tuning process. The above swept-source light sources cannot present high-quality OCT imaging at a fast speed.
The invention realizes the optical fiber output of ultrashort laser pulse based on passive mode locking and realizes the time domain separation of wavelength by utilizing the dispersion time stretching outside the cavity, thereby realizing the output of high-speed frequency-sweeping light source and providing high-quality frequency-sweeping light source for OCT system.
Disclosure of Invention
The invention aims to provide a high-speed frequency sweep optical fiber light source, which outputs high-repetition-frequency broad-spectrum mode-locking pulses through a passive mode-locking pulse light source, and realizes high-speed frequency sweep in a time domain through dispersion time stretching of the pulses outside a cavity.
In order to solve the technical problems, the invention is realized by the following technical scheme:
a high-speed sweep frequency optical fiber light source comprises high-repetition frequency mode-locked pulses output by a mode-locked pulse light source, and has a wider spectrum, the dispersion transmission of the high-speed sweep frequency optical fiber light source follows a parabolic differential equation similar to one-dimensional paraxial diffraction, and is similar to Fraunhofer diffraction;
the high repetition frequency mode-locking pulse is subjected to laser pulse energy and peak power increase by an optical fiber amplifier outside the cavity, and then a pulse supercontinuum light source is obtained by widening a high nonlinear optical fiber;
the pulse supercontinuum light source is stretched after a large dispersion medium is provided by a dispersion optical fiber to obtain a pulse frequency domain spectrum, and the pulse frequency domain spectrum is mapped to a time domain waveform, so that a sweep frequency light source on a time domain is realized.
Further, the mode-locked pulse light source comprises a laser, the laser generates a monochromatic laser light source as a pumping light source, and the monochromatic laser light source flows into a section of gain medium through a Wavelength Division Multiplexer (WDM) to gain;
a polarization-dependent isolator (PS-ISO) is adopted to inhibit backward feedback so as to ensure unidirectional running of the ring cavity laser;
a Polarization Controller (PC) is adopted to adjust the polarization state of light waves in the laser, after the pulses are transmitted into the PC and the PS-ISO, the pulses are further narrowed in a time domain under the action of a Nonlinear Polarization Rotation (NPR) effect, and two wing parts of a frequency domain are filtered out at the same time;
single Mode Fiber (SMF) is used as connection, and the coupling proportion of an Output Coupler (OC) is 90: by properly adjusting the polarization state of the PC, the laser can self-start when the pump power exceeds a certain threshold, under the NPR effect.
Furthermore, the laser comprises an active mode-locked pulse laser, a nonlinear polarization rotation mode-locked pulse laser, a saturable absorber mode-locked pulse laser, a Fourier frequency domain transformation mode-locked pulse laser and a nonlinear optical fiber environment pulse laser.
Further, the optical fiber amplifier includes: rare earth doped fiber amplifier, Raman fiber amplifier, and semiconductor optical amplifier.
Further, the high nonlinearity fiber comprises: fine core optical fiber, nanowire waveguide, and photonic crystal fiber.
Furthermore, the dispersion fiber is a medium with a length enough to provide larger dispersion, and is used for dispersion regulation of the high-nonlinearity fiber, and the spectral width and flatness of the output pulse supercontinuum are regulated, so that the sweep frequency range of the sweep frequency light source is regulated.
Furthermore, the dispersion fiber changes the dispersion amount by adjusting the length of the dispersion fiber, and is used for adjusting the sweep frequency speed and the frequency resolution of the output sweep frequency light source.
Further, the dispersion fiber comprises a dispersion displacement fiber, a dispersion compensation fiber and a single mode fiber.
The invention has the following beneficial effects: (1) the light source is of an all-fiber structure, and has no optical coupling device, compact structure and easy installation and adjustment. (2) The spectrum width obtained by nonlinear broadening is large, and large-range spectrum scanning can be realized. (3) The sweep frequency range of the light source can be adjusted by the dispersion regulation and control of the nonlinear optical fiber. (4) The sweep frequency speed of the light source can reach hundreds of MHz magnitude, and the sweep frequency speed far exceeds that of the traditional sweep frequency light source.
Drawings
FIG. 1 is a schematic view of the apparatus of the present invention.
FIG. 2 is a schematic diagram of the present invention with a pump light source.
FIG. 3 is a pulse sequence diagram of the laser output of the present invention.
FIG. 4 is a spectrum in logarithmic scale according to the invention.
FIG. 5 is a graph showing a comparison of the pulse broadening after dispersion stretching under DFT and a spectrum under linear coordinates according to the present invention.
FIG. 6 is a diagram of the fundamental frequency spectrum of the present invention.
Fig. 7 is a diagram of a higher harmonic spectrum.
Detailed Description
The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.
As shown in fig. 1-2, the device structure consists of a pulse seed source, a fiber amplifier, a high nonlinear fiber, and a dispersion compensating fiber; the pulse seed source consists of a wavelength division multiplexer, a gain medium, a polarization-related isolator, a polarization controller, a single-mode optical fiber for connection and an output coupler. In the example, a monochromatic laser light source with the working wavelength of 980nm is used as a pumping light source, and then a Wavelength Division Multiplexer (WDM) is used for gaining a length of 10m low erbium-doped fiber which flows in and flows into the low erbium-doped fiber; the device adopts a polarization-dependent isolator (PS-ISO) to inhibit backward feedback so as to ensure the unidirectional running of the ring cavity laser; and a Polarization Controller (PC) is adopted to adjust the polarization state of the light wave in the laser; after the pulse is transmitted into the PC and the PS-ISO, under the action of the NPR effect, the pulse is further narrowed in a time domain, and two wing parts of a frequency domain are simultaneously filtered; the device adopts a Single Mode Fiber (SMF) as a connection, and the total length of the device is 1.6 m; the coupling ratio of an Output Coupler (OC) is selected from 90: 10. under the action of NPR effect, due to factors such as saturated absorption and self-phase modulation in the laser, the polarization state of the PC is properly adjusted, and when the pumping power exceeds a certain threshold value, the laser can be automatically started; observing the output signal by an oscilloscope, and observing the pulse sequence shown in the figure 3, wherein the pulse period T is 64.6 ns; the device adopts a fiber amplifier (FiberAmplifier) to amplify the power of the output laser pulse outside the cavity, adopts a high nonlinear fiber (HNLF) to enhance the nonlinear effect of the fiber, and adopts a Dispersion Compensation Fiber (DCF) with the length of 5km to perform pulse broadening on the laser pulse output by the output coupler, thereby realizing the output of a high-speed frequency sweeping light source.
FIG. 4 is a logarithmic spectrum chart measured by a spectrometer, the 3dB bandwidth reaches 54.15nm, the mode locking of a wide spectrum is realized, and the mode locking spectrum is flat; fig. 5 shows a pulse-stretched spectrum measured with an oscilloscope and subjected to Discrete Fourier Transform (DFT), where the shape of the pulse can correspond to the spectrum in linear coordinates, since the dispersion stretch of the wavelength is linear, and the shapes of the two are approximately the same.
As shown in FIG. 6, the fundamental frequency pulse has a narrow structure, a center frequency of 15.37MHz, a signal-to-noise ratio (SNR) of more than 75dB, and extremely stable mode locking; as can be seen from fig. 7, the harmonic pulse height is kept uniform in the maximum frequency range, that is, the pulse width of the laser light source is narrow, and the laser light source is an ultra-short pulse and has high energy. In conclusion, the all-fiber high-speed frequency-sweeping optical fiber light source with the frequency-sweeping frequency of 15.37MHz, the frequency-sweeping range of 54.15nm and the frequency-sweeping precision of 0.13nm is realized by combining the embodiment.
The above-disclosed preferred embodiments of the present invention are provided merely as an aid in explaining the present invention and for better explaining the principles and practical applications of the present invention so as to enable those skilled in the art to better understand and utilize the present invention.

Claims (9)

1. A high speed swept frequency fiber optic source, comprising:
the high-repetition-frequency mode-locked pulse output by the mode-locked pulse light source is included, the wide spectrum is provided, the dispersion transmission of the high-repetition-frequency mode-locked pulse is subject to a parabolic differential equation similar to one-dimensional paraxial diffraction, and the high-repetition-frequency mode-locked pulse is similar to Fraunhofer diffraction;
the high repetition frequency mode-locking pulse is subjected to laser pulse energy and peak power increase by an optical fiber amplifier outside the cavity, and then a pulse supercontinuum light source is obtained by widening a high nonlinear optical fiber;
the pulse supercontinuum light source is stretched after a large dispersion medium is provided by a dispersion optical fiber to obtain a pulse frequency domain spectrum, and the pulse frequency domain spectrum is mapped to a time domain waveform, so that a sweep frequency light source on a time domain is realized.
2. A high speed swept optical fiber source as claimed in claim 1, wherein: the mode locking pulse light source comprises a laser, wherein the laser generates a monochromatic laser light source as a pumping light source, the monochromatic laser light source flows into a section of gain medium for gain through a Wavelength Division Multiplexer (WDM), and then the gain medium is output after being coupled through a coupler (OC) to obtain the mode locking pulse light source, and the coupling proportion of the coupler (OC) is 90: 10.
3. a high speed swept optical fiber source as claimed in claim 2, wherein: the coupler (OC) comprises a second output end, and the second output end adopts a polarization-dependent isolator (PS-ISO) to inhibit backward feedback so as to ensure unidirectional running of the ring cavity laser;
a Polarization Controller (PC) is adopted to adjust the polarization state of light waves in the laser, after the pulses are transmitted into the PC and the PS-ISO, the pulses are further narrowed in a time domain under the action of a Nonlinear Polarization Rotation (NPR) effect, and two wing parts of a frequency domain are filtered out at the same time;
by adopting a Single Mode Fiber (SMF) as a connection, under the action of NPR effect, the polarization state of PC is properly adjusted, and when the pump power exceeds a certain threshold value, the laser can realize self-starting.
4. A high speed swept optical fiber source as claimed in claim 2, wherein: the laser comprises an active mode-locked pulse laser, a nonlinear polarization rotation mode-locked pulse laser, a saturable absorber mode-locked pulse laser, a Fourier frequency domain transformation mode-locked pulse laser and a nonlinear optical fiber environment pulse laser.
5. A high speed swept optical fiber source as claimed in claim 1, wherein: the optical fiber amplifier includes: rare earth doped fiber amplifier, Raman fiber amplifier, and semiconductor optical amplifier.
6. A high speed swept optical fiber source as claimed in claim 1, wherein: the high nonlinear optical fiber includes: fine core optical fiber, nanowire waveguide, and photonic crystal fiber.
7. A high speed swept optical fiber source as claimed in claim 1 or 2, wherein: the dispersion fiber is a medium with a length enough to provide larger dispersion, is used for dispersion regulation and control of the high-nonlinearity fiber, and is used for regulating the spectral width and the flatness of an output pulse super-continuum spectrum so as to regulate the sweep frequency range of a sweep frequency light source.
8. A high speed swept optical fiber source as claimed in claim 7, wherein: the dispersion fiber changes the dispersion amount by adjusting the length of the dispersion fiber, and is used for adjusting the sweep frequency speed and the frequency resolution of the output sweep frequency light source.
9. A high speed swept optical fiber source as claimed in claim 1, 7 or 8, wherein: the dispersion optical fiber comprises a dispersion displacement optical fiber, a dispersion compensation optical fiber and a single mode optical fiber.
CN202210313891.0A 2022-03-28 2022-03-28 High-speed frequency-sweeping optical fiber light source Pending CN114825004A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210313891.0A CN114825004A (en) 2022-03-28 2022-03-28 High-speed frequency-sweeping optical fiber light source

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210313891.0A CN114825004A (en) 2022-03-28 2022-03-28 High-speed frequency-sweeping optical fiber light source

Publications (1)

Publication Number Publication Date
CN114825004A true CN114825004A (en) 2022-07-29

Family

ID=82530077

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210313891.0A Pending CN114825004A (en) 2022-03-28 2022-03-28 High-speed frequency-sweeping optical fiber light source

Country Status (1)

Country Link
CN (1) CN114825004A (en)

Similar Documents

Publication Publication Date Title
US7477665B2 (en) Electronically tuned self-starting polarization shaping mode locked fiber laser
US7720114B2 (en) Nonlinear polarization pulse shaping mode locked fiber laser
CN101924319B (en) All-fiber structure laser system capable of generating high-energy femtosecond pulse
CN105244744B (en) A kind of light comb system that the control of bandwidth carrier envelope offset frequency is realized using electro-optic crystal
CN109038191B (en) Spectrum limited Fourier domain mode-locked fiber laser
EP1962135A1 (en) Optical compressor and ultra-short pulse light source
CN106207722A (en) Dissipative solitons based on dispersion compensating fiber and orphan's dual laser
CN103151682B (en) Anti-Strokes Raman fiber laser achieving multi-wavelength output
CN102005689A (en) All-fiber structural laser system capable of generating high-energy wave-free split rectangular pulse
CN103078245B (en) Dissipation soliton active mode-locking fiber laser
CN103124044A (en) Frequency interval adjustable multi-wavelength anti-Stokes four-wave mixing (FWM) fiber laser
Wu et al. Femtosecond soliton erbium-doped fiber laser with a symmetrical GIMF–SIMF–GIMF saturable absorber
Wang et al. Multiwavelength generation in a Raman fiber laser with sampled Bragg grating
CN114825004A (en) High-speed frequency-sweeping optical fiber light source
Pan et al. Dual-pulse actively Q-switched fiber laser based on EOM and sagnac loop
RU162919U1 (en) COMPACT RING ERBIUM FIBER LASER WITH MOD SYNCHRONIZATION BASED ON A HIGH NONLINEAR LIGHT FILTER
CN206313278U (en) A kind of microwave signal generator
Osterberg et al. Autocorrelation of short pulses using a single-mode fiber
CN107706704B (en) 1.7 mu m wave band picosecond double-pulse optical fiber light source
Yuan et al. Mid-infrared dual electro-optic comb spectroscopy with tunable spectral resolution
Huang et al. Dual pulse bound states in a dispersion-managed mode-locked all-fiber laser with 101.75 MHz repetition rate using 45° tilted fiber grating
CN208226293U (en) A kind of multi-wavelength broadband tunable microwave signal generator
Huang et al. Passively harmonic mode-locking in an Erbium-doped fiber laser based on carbon nanotubes film at repetition rates to 500MHz
Genier et al. Recent advances in ultra-low noise coherent supercontinuum generation
Jia et al. Generation of dual-wavelength square wave pulse in a passively mode-locked erbium-doped fiber laser

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination