WO2017204299A1 - Source de lumière pulsée et procédé de génération de lumière pulsée - Google Patents

Source de lumière pulsée et procédé de génération de lumière pulsée Download PDF

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Publication number
WO2017204299A1
WO2017204299A1 PCT/JP2017/019559 JP2017019559W WO2017204299A1 WO 2017204299 A1 WO2017204299 A1 WO 2017204299A1 JP 2017019559 W JP2017019559 W JP 2017019559W WO 2017204299 A1 WO2017204299 A1 WO 2017204299A1
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Prior art keywords
light source
resonator
pulse light
pulse
pump
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PCT/JP2017/019559
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English (en)
Japanese (ja)
Inventor
ジイヨン セット
山下　真司
宇 王
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国立大学法人 東京大学
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Priority to JP2018519609A priority Critical patent/JP7043073B2/ja
Publication of WO2017204299A1 publication Critical patent/WO2017204299A1/fr

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    • 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
    • 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
    • H01S3/08—Construction or shape of optical resonators or components thereof
    • 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
    • H01S3/08—Construction or shape of optical resonators or components thereof
    • H01S3/081—Construction or shape of optical resonators or components thereof comprising three or more reflectors
    • H01S3/083—Ring lasers
    • 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
    • H01S3/09—Processes or apparatus for excitation, e.g. pumping
    • H01S3/091—Processes or apparatus for excitation, e.g. pumping using optical pumping
    • H01S3/094—Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light
    • 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
    • H01S3/13—Stabilisation of laser output parameters, e.g. frequency or amplitude
    • H01S3/131—Stabilisation of laser output parameters, e.g. frequency or amplitude by controlling the active medium, e.g. by controlling the processes or apparatus for excitation

Definitions

  • the present invention relates to a pulse light source and a method for generating pulsed light.
  • REDFAs Rare earth doped fiber amplifiers
  • REDFA includes, for example, praseodymium ion (Pr 3+ ), neodymium ion (Nd 3+ ), holmium ion (Ho 3+ ), erbium ion (Er 3+ ), thulium ion (Tm 3+ ), or ytterbium ion (Yb 3+ ).
  • a REDFA containing thulium ions (Tm 3+ ) that is, a laser having a thulium-doped fiber amplifier (TDFA), can emit light having a wavelength of 2 ⁇ m.
  • the light in the wavelength band of 2 ⁇ m is expected to be applied to, for example, laser processing, LIDAR (Laser Imaging Detection And Ranging) or gas sensing.
  • LIDAR Laser Imaging Detection And Ranging
  • a laser having REDFA may generate pulsed light.
  • One method for generating pulsed light is mode synchronization. Furthermore, there are two types of mode synchronization, passive mode synchronization and active mode synchronization.
  • the pulse light source includes a resonator, a gain medium, and a saturable absorber.
  • the gain medium and the saturable absorber are between the two mirrors of the resonator.
  • the light loss of the saturable absorber is modulated by the intensity of light input to the saturable absorber, and specifically, the light loss decreases as the light intensity increases.
  • pulsed light can be generated by this loss modulation of the saturable absorber.
  • the pulsed light source includes a resonator, a gain medium, and an intensity modulator.
  • the gain medium and intensity modulator are between the two mirrors of the resonator.
  • the loss of the intensity modulator is modulated by a signal from the outside of the resonator.
  • pulsed light can be generated by this loss modulation of the intensity modulator.
  • the pulse light source in another example of active mode locking, includes a pump light source, a resonator, and a gain medium.
  • the pump light source is external to the resonator.
  • the gain medium is between the two mirrors of the resonator, and is TDFA in Non-Patent Documents 1 and 2.
  • Pulse light is supplied from the pump light source.
  • pulsed light is generated from the resonator by the pulsed light from the pump light.
  • pulse light may be supplied from a pump light source to a resonator as in active mode synchronization described in Non-Patent Documents 1 and 2.
  • the present inventor studied generating pulsed light by a new active mode synchronization different from the active mode synchronization described in Non-Patent Documents 1 and 2.
  • An object of the present invention is to generate pulsed light by a novel active mode synchronization in a pulsed light source having REDFA.
  • a resonator having a rare earth doped fiber amplifier having a rare earth doped fiber amplifier;
  • a pulse light source is provided in which the pump light is modulated by a modulation signal having a modulation frequency of 95% or more and 105% or less of an integral multiple of the basic resonance frequency of the resonator.
  • a method for generating pulsed light comprising: A resonator having a rare earth-doped fiber amplifier and a pump light source capable of supplying pump light modulated with a modulation signal having a modulation frequency of 95% or more and 105% or less of an integral multiple of the basic resonance frequency of the resonator are provided. To do; Supplying the pump light from the pump light source to the rare earth doped fiber amplifier; After the pump light is supplied from the pump light source to the rare earth doped fiber amplifier, the light is output from the resonator.
  • pulse light can be generated by a novel active mode synchronization in a pulse light source having REDFA.
  • FIG. 1 It is a figure which shows the measurement result of RF spectrum of the pulsed light output from the pulse light source which concerns on Example 1.
  • FIG. It is a figure which shows the measurement result of the autocorrelation of the pulsed light output from the pulse light source which concerns on Example 1.
  • FIG. It is a figure which shows the measurement result of the pulsed light output from the pulse light source which concerns on Example 2.
  • FIG. It is a figure which shows the measurement result of the optical spectrum of the pulsed light output from the pulse light source which concerns on Example 3.
  • FIG. It is a figure which shows the measurement result of the autocorrelation of the pulsed light output from the pulse light source which concerns on Example 3.
  • FIG. It is a figure which shows the measurement result of RF spectrum of the pulsed light output from the pulse light source which concerns on Example 3.
  • FIG. 1 is a diagram illustrating a pulse light source 10 according to the first embodiment.
  • the pulse light source 10 includes a pump light source 100, a resonator 200, and an output unit 300.
  • the resonator 200 includes a rare earth doped fiber amplifier (REDFA) 220.
  • the pump light source 100 supplies pump light to the REDFA 220.
  • the pump light is modulated by a modulation signal having a modulation frequency f mod substantially equal to an integral multiple of the basic resonance frequency f 1 of the resonator 200.
  • the modulation frequency f mod is 95% or more and 105% or less, preferably 99% or more and 101% or less, more preferably 100 ⁇ 0.1% of an integral multiple of the basic resonance frequency f 1 of the resonator 200. Is the frequency.
  • Pulse light is output from the output unit 300 of the pulse light source 10 at a repetition frequency equal to the modulation frequency f mod .
  • active mode synchronization with a repetition frequency equal to the modulation frequency f mod is realized. Details will be described below.
  • FIG. 2 is a diagram showing a first example of the pump light source 100 shown in FIG.
  • the pump light source 100 includes a pump laser 110, an optical amplifier 120, an electric signal generator 130, and a laser driver 140.
  • the pump laser 110 emits seed light having a wavelength that excites rare earth ions contained in the REDFA 220 (FIG. 1).
  • the seed light from the pump laser 110 is amplified by the optical amplifier 120.
  • the REDFA 220 (FIG. 1) contains thulium ions (Tm 3+ )
  • the wavelength of the seed light of the pump laser 110 is 1570 nm
  • the optical amplifier 120 is a C-band erbium doped fiber amplifier (EDFA).
  • the electrical signal generator 130 modulates the seed light of the pump laser 110 with a sine wave that oscillates at the modulation frequency f mod .
  • the electric signal generator 130 modulates the seed light of the pump laser 110 via the laser driver 140. In this way, the pump light from the pump light source 100 is modulated by the modulation signal having the modulation frequency f mod .
  • the electric signal generator 130 may modulate the seed light of the pump laser 110 with a rectangular wave that oscillates at the modulation frequency f mod .
  • the duty ratio T on / T mod of this rectangular wave may be 0.50 or may be different from 0.50.
  • the pump light from the pump light source 100 is modulated by the modulation signal having the modulation frequency f mod .
  • the degree of modulation by the electric signal generator 130 is preferably high to some extent, and is preferably 10% or more, for example. When the degree of modulation by the electric signal generator 130 is high to some extent, the pump light is sufficiently modulated. However, the degree of modulation by the electric signal generator 130 is not limited to the above example (10% or more).
  • FIG. 3 is a diagram showing a second example of the pump light source 100 shown in FIG.
  • the pump light source 100 may not include the optical amplifier 120 (FIG. 2).
  • the seed light (pump light) from the pump laser 110 is directly supplied to the resonator 200 without passing through the optical amplifier 120 (FIG. 2).
  • FIG. 4 is a diagram showing a third example of the pump light source 100 shown in FIG.
  • the seed light from the pump laser 110 may be modulated by a light intensity modulator 150 and an electric signal generator 130.
  • the laser driver 140 is a DC laser driver, for example, and does not modulate the seed light from the pump laser 110.
  • the light intensity modulator 150 is located between the pump laser 110 and the optical amplifier 120, and modulates the seed light from the pump laser 110 by a signal (for example, a sine wave or a rectangular wave) from the electric signal generator 130.
  • the pulse light source 10 includes a pump light source 100 and a resonator 200.
  • the resonator 200 includes an optical multiplexer 210, a REDFA 220, an isolator (ISO) 230, and an optical demultiplexer 240.
  • the optical multiplexer 210, the REDFA 220, the isolator 230, and the optical demultiplexer 240 are optically coupled to each other via an optical fiber.
  • the pump light source 100 is optically coupled to the optical multiplexer 210 of the resonator 200 via an optical fiber.
  • the output unit 300 is optically coupled to the optical demultiplexer 240 via an optical fiber.
  • the resonator 200 is a forward-excited ring resonator.
  • the pump light from the pump light source 100 passes through the optical multiplexer 210 between the front of the isolator 230 and the rear of the REDFA 220 in the forward direction of the isolator 230 (light propagation direction in the resonator 200). Have been supplied.
  • the pump light from the pump light source 100 is input to the REDFA 220 via the optical multiplexer 210.
  • the optical multiplexer 210 combines the pump light from the pump light source 100 and the light from the optical demultiplexer 240, and is specifically a WDM (Wavelength Division Multiplexing) coupler.
  • the rare earth ions contained in the REDFA 220 are excited by the pump light. Furthermore, light is emitted from the REDFA 220 when the excited rare earth ions transition to a low energy level.
  • Light from the REDFA 220 is input to the optical demultiplexer 240 via the isolator 230.
  • Part of the light from the isolator 230 is input to the optical multiplexer 210 via the optical demultiplexer 240 and further input to the REDFA 220 via the optical multiplexer 210.
  • Another part of the light from the isolator 230 is input to the output unit 300 via the optical demultiplexer 240 and further output to the outside of the pulse light source 10 via the output unit 300.
  • the optical demultiplexer 240 demultiplexes the light from the isolator 230 into two lights having the same wavelength, for example, 50:50, and is specifically an optical coupler.
  • the REDFA 220 functions as a gain medium for the resonator 200.
  • REDFA 220 includes glass fibers and rare earth ions doped into the glass fibers.
  • the rare earth ions contained in REDFA 220 include, for example, praseodymium ions (Pr 3+ ), neodymium ions (Nd 3+ ), holmium ions (Ho 3+ ), erbium ions (Er 3+ ), thulium ions (Tm 3+ ), and ytterbium ions (Yb 3+). At least one selected from the group consisting of:
  • the output unit 300 is, for example, an isolator.
  • the output unit 300 in the output unit 300 (isolator), light traveling from the resonator 200 toward the outside of the pulse light source 10 passes through the output unit 300, and light traveling from the outside of the pulse light source 10 toward the resonator 200 is blocked by the output unit 300. It is arranged so that.
  • the q-order resonance frequency f q of the resonator 200 is expressed by the following equation (1).
  • f q qc / (nL 1 ) (1)
  • c the speed of light
  • n the refractive index of the optical fiber of the resonator 200
  • L 1 the length of the resonator 200.
  • the resonance frequency f q is the basic resonance frequency f 1 .
  • pump light is supplied from the pump light source 100 to the REDFA 220 of the resonator 200.
  • the pump light is modulated by the modulation signal having the modulation frequency f mod substantially equal to the integral multiple of the basic resonance frequency f 1 of the resonator 200.
  • the present inventor examined, when the lifetime ⁇ of the upper level ( 3 F 4 ) of the rare earth ions contained in the REDFA 220 is somewhat shorter than the modulation signal repetition period T mod (T mod 1 / f mod ), Specifically, when the ratio tau / T mod lifetime tau for the repetition period T mod is for example, at 1 ⁇ 10 4 or less, equal to the modulation frequency f mod in Radio-frequency (RF) spectrum of the signal from the output unit 300 It became clear that a peak appeared in the frequency (for example, see FIG. 19 described later). Furthermore, it has been clarified that the intensity of the peak increases as the repetition period T mod increases (that is, the modulation frequency f mod decreases) when the lifetime ⁇ is constant. This result indicates that the peak is due to the modulation of the electric signal generator 130.
  • RF Radio-frequency
  • the lifetime ⁇ is about 8 ms to 10 ms for erbium ion (Er 3+ ), about 1 ms to 2 ms for ytterbium ion (Yb 3+ ), and erbium for thulium ion (Tm 3+ ). It is shorter than the lifetime of ions (Er 3+ ) and the lifetime of ytterbium ions (Yb 3+ ), specifically, approximately 400 ⁇ s or more and 500 ⁇ s or less.
  • the modulation frequency f mod is substantially equal to an integral multiple of the basic resonance frequency f 1 of the resonator 200. For this reason, mode synchronization of a repetition frequency equal to the modulation frequency f mod , specifically, Continuous Wave (CW) active mode synchronization is realized. For this reason, pulse light is output from the output unit 300 of the pulse light source 10 at a repetition frequency equal to the modulation frequency f mod .
  • CW Continuous Wave
  • the modulation frequency f mod is 95% or more and 105% or less, preferably 99% or more and 101% or less, more preferably 100 ⁇ 0.1% of an integral multiple of the basic resonance frequency f 1 of the resonator 200. is there.
  • the pump light from the pump light source 100 is modulated by the modulation signal having the modulation frequency f mod substantially equal to the integral multiple of the basic resonance frequency f 1 of the resonator 200.
  • pulse light is output from the output unit 300 of the pulse light source 10 at a repetition frequency equal to the modulation frequency f mod .
  • pulsed light having a pulse width on the order of picoseconds (10 ⁇ 12 seconds), that is, ultrashort pulsed light can be generated.
  • the wavelength of the pulsed light generated from the pulsed light source 10 can be set to the near infrared wavelength.
  • the wavelength of the pulsed light can be in the 2 ⁇ m band
  • the wavelength of the pulsed light can be in the 1.5 ⁇ m band
  • the wavelength of the pulsed light can be in the 1 ⁇ m band.
  • FIG. 5 is a diagram showing a modification of FIG.
  • the resonator 200 may be a backward-pumped ring resonator.
  • the pump light from the pump light source 100 is between the front of the REDFA 220 and the rear of the isolator 230 in the forward direction of the isolator 230 (light propagation direction in the resonator 200). It is supplied via the optical multiplexer 210.
  • FIG. 6 is a diagram showing a pulse light source 10 according to the second embodiment, and corresponds to FIG. 1 of the first embodiment.
  • the pulse light source 10 according to the present embodiment is the same as the pulse light source 10 according to the first embodiment except for the following points.
  • the resonator 200 is a linear resonator.
  • the resonator 200 includes a REDFA 220, a first reflective element 252 and a second reflective element 254.
  • the REDFA 220 is between the first reflective element 252 and the second reflective element 254.
  • the first reflective element 252 and the second reflective element 254 function as a mirror of the resonator 200.
  • the first reflective element 252 is a mirror or FBG (Fiber Bragg Grating).
  • the second reflective element 254 reflects a part of the light from the REDFA 220 and transmits the other part of the light from the REDFA 220. More specifically, the 2nd reflective element 254 is a mirror or FBG, for example.
  • Pump light from the pump light source 100 is supplied to the REDFA 220 via the optical multiplexer 210 between the first reflective element 252 and the REDFA 220.
  • Light from the resonator 200 is output to the outside of the pulse light source 10 via the second reflective element 254, the isolator 230, and the output unit 300.
  • the q-order resonance frequency f q of the resonator 200 is expressed by the following equation (2).
  • f q qc / (2nL 2 ) (2)
  • c is the speed of light
  • n is the refractive index of the optical fiber of the resonator 200
  • L 2 is the length of the resonator 200.
  • the resonance frequency f q is the basic resonance frequency f 1 .
  • the pump light from the pump light source 100 is modulated by a modulation signal having a modulation frequency f mod that is substantially equal to an integral multiple of the fundamental resonance frequency f 1 of the resonator 200.
  • pulse light is output from the output unit 300 of the pulse light source 10 at a repetition frequency equal to the modulation frequency f mod .
  • FIG. 7 is a diagram showing a first modification of FIG.
  • the resonator 200 is a linear resonator.
  • the pump light from the pump light source 100 may be supplied via an optical multiplexer 210 between the REDFA 220 and the second reflective element 254.
  • FIG. 8 is a diagram showing a second modification of FIG.
  • the resonator 200 is a linear resonator.
  • the pump light from the pump light source 100 may be supplied to the REDFA 220 via the first reflective element 252.
  • the first reflecting element 252 functions as an element that reflects light of a specific wavelength, and specifically, transmits the pump light from the pump light source 100 and reflects the light emitted from the REDFA 220. More specifically, the first reflective element 252 is, for example, a multilayer film mirror or an FBG (Fiber Bragg Grating).
  • FIG. 9 is a diagram showing a pulse light source 10 according to the third embodiment, and corresponds to FIG. 1 of the first embodiment.
  • the pulse light source 10 according to the present embodiment is the same as the pulse light source 10 according to the first embodiment except for the following points.
  • the resonator 200 is an 8-shaped resonator. Specifically, the resonator 200 has a first loop 202 and a second loop 204. The first loop 202 and the second loop 204 are optically coupled to each other via an optical demultiplexer 242 (specifically, an optical coupler).
  • the first loop 202 includes a REDFA 220 and a nonlinear fiber 260. Pump light from the pump light source 100 is supplied to the REDFA 220.
  • the second loop 204 includes an isolator 230 and an optical demultiplexer 240.
  • the optical demultiplexer 240 is optically coupled to the output unit 300 via an optical fiber.
  • the pump light from the pump light source 100 is modulated by a modulation signal having a modulation frequency f mod that is substantially equal to an integral multiple of the fundamental resonance frequency f 1 of the resonator 200.
  • pulse light is output from the output unit 300 of the pulse light source 10 at a repetition frequency equal to the modulation frequency f mod .
  • FIG. 10 is a view showing a pulse light source 10 according to the fourth embodiment, and corresponds to FIG. 1 of the first embodiment.
  • the pulse light source 10 according to the present embodiment is the same as the pulse light source 10 according to the first embodiment except for the following points.
  • the resonator 200 is a sigma resonator.
  • the resonator 200 includes a REDFA 220, an isolator 230, an optical demultiplexer 240, a reflecting element 256, and a PBS (Polarizing Beam Splitter) 270.
  • the REDFA 220 is between the reflective element 256 and the PBS 270. Pump light from the pump laser 110 is supplied to the REDFA 220.
  • the reflection element 256 is a Faraday mirror and reflects light so that the polarization direction of the reflected light is rotated by 90 ° from the polarization direction of the incident light.
  • the PBS 270, isolator 230, and optical demultiplexer 240 are optically coupled via a polarization maintaining fiber.
  • the isolator 230 is provided between the PBS 270 and the optical demultiplexer 240, and is provided so that the forward direction of the isolator 230 is the direction from the PBS 270 toward the optical demultiplexer 240.
  • the polarization maintaining fiber on the optical demultiplexer 240 side and the polarization maintaining fiber on the PBS 270 side are fused at the fusion part 280. Specifically, these polarization maintaining fibers are fused at the fusion part 280 so that the polarization direction on the optical demultiplexer 240 side and the polarization direction on the PBS 270 side are rotated by 90 °.
  • the pump light from the pump light source 100 is modulated by a modulation signal having a modulation frequency f mod that is substantially equal to an integral multiple of the fundamental resonance frequency f 1 of the resonator 200.
  • pulse light is output from the output unit 300 of the pulse light source 10 at a repetition frequency equal to the modulation frequency f mod .
  • FIG. 11 is a diagram showing a pulse light source 10 according to the fifth embodiment, and corresponds to FIG. 5 of the first embodiment.
  • the pulse light source 10 according to the present embodiment is the same as the pulse light source 10 according to the first embodiment except for the following points.
  • the resonator 200 is a ring resonator.
  • the resonator 200 may include a saturable absorber 292.
  • the saturable absorber 292 is located between the optical multiplexer 210 and the isolator 230.
  • the pump light from the pump light source 100 is an optical multiplexer between the front of the REDFA 220 and the rear of the isolator 230 in the forward direction of the isolator 230 (the propagation direction of light in the resonator 200). 210 is supplied.
  • FIG. 12 is a diagram showing a pulse light source 10 according to the sixth embodiment, and corresponds to FIG. 6 of the second embodiment.
  • the pulse light source 10 according to the present embodiment is the same as the pulse light source 10 according to the second embodiment except for the following points.
  • the resonator 200 is a linear resonator. As shown in the figure, the resonator 200 may include a saturable absorbing mirror 294 instead of the first reflecting element 252 (FIG. 6). In the example shown in the drawing, the pump light from the pump light source 100 is supplied via the optical multiplexer 210 between the saturable absorption mirror 294 and the REDFA 220.
  • FIG. 13 is a diagram showing a laser processing apparatus according to the seventh embodiment.
  • the laser processing apparatus includes a pulse light source 10, a mirror 12, a lens 14, and a nozzle 16.
  • the laser processing apparatus is used for processing the object W.
  • the object W is, for example, an iron plate, a glass plate, or a plastic plate.
  • the pulse light source 10 according to this embodiment is the pulse light source 10 according to any one of the first to sixth embodiments. Pulse light is output from the pulse light source 10.
  • the pulsed light is reflected by the mirror 12 and enters the lens 14.
  • the pulsed light is collected by the lens 14 and then passes through the nozzle 16 and is irradiated onto the object W.
  • the pulse width of the pulsed light irradiated from the pulse light source 10 onto the object W can be on the order of picoseconds (10 ⁇ 12 seconds) and can be very narrow. For this reason, the region irradiated with the pulsed light is removed in a short time. For this reason, it is possible to suppress the diffusion of heat around the area removed by the pulsed light.
  • the peak intensity of the pulsed light irradiated from the pulsed light source 10 to the object W is very large. For this reason, the probability that a multiphoton optical absorption process will occur in the object W increases. For this reason, in this embodiment, even if it is a case where the target object W consists of translucent materials like glass, the target object W can be processed.
  • FIG. 14 is a diagram illustrating an optical sensor according to the eighth embodiment.
  • the optical sensor is Laser Imaging Detection And Ranging (LIDAR), and includes a pulse light source 10 and a detector 20.
  • the pulse light source 10 according to this embodiment is the pulse light source 10 according to any one of the first to sixth embodiments.
  • the detector 20 is specifically a CCD (Charge-Coupled Device) image sensor.
  • pulsed light is output from the pulsed light source 10 toward the object W.
  • the detector 20 detects the pulsed light reflected from the object W.
  • the optical sensor can calculate the distance from the pulse light source 10 to the object W based on the time from when the pulse light is output from the pulse light source 10 until the detector 20 detects the pulse light.
  • the optical sensor is mounted on a vehicle (for example, an automobile or a motorcycle).
  • a front or rear object W of the vehicle can be detected.
  • a light sensor is used for mapping. More specifically, for example, when an optical sensor is mounted on an airplane, the shape of the earth surface can be measured by mapping from the sky.
  • FIG. 15 is a diagram illustrating a medical device according to the ninth embodiment.
  • the medical device includes a pulse light source 10, a mirror 12, a lens 14, and a nozzle 16 in the same manner as the laser processing apparatus shown in FIG.
  • the pulse light source 10 according to this embodiment is the pulse light source 10 according to any one of the first to sixth embodiments.
  • the object W is a living tissue, specifically, for example, skin. In the example shown in the figure, the pulsed light from the pulse light source 10 is applied to the object W in the same manner as in the example shown in FIG.
  • the pulse width of the pulsed light irradiated from the pulse light source 10 onto the object W can be on the order of picoseconds (10 ⁇ 12 seconds) and can be very narrow. For this reason, the region irradiated with the pulsed light is removed in a short time. For this reason, it is possible to suppress the diffusion of heat around the area removed by the pulsed light.
  • FIG. 16 is a diagram illustrating a gas sensor according to the tenth embodiment.
  • the gas sensor is used to analyze the gas G.
  • the gas sensor includes a pulse light source 10 and a detector 20.
  • the pulse light source 10 according to this embodiment is the pulse light source 10 according to any one of the first to sixth embodiments.
  • the pulsed light from the pulsed light source 10 passes through the gas G and then reaches the detector 20.
  • the detector 20 detects the pulsed light from the pulse light source 10. Based on the detection result of the detector 20, the kind of gas contained in the gas G is analyzed. Specifically, light having a part of the wavelength of the pulsed light is absorbed in the gas G. Based on this wavelength, the type of gas contained in the gas G is analyzed.
  • Example 1 The pulse light source 10 shown in FIG. 1 was produced.
  • the pump light source 100 was as shown in FIG.
  • the pump laser 110 was a 1.57 ⁇ m wavelength laser.
  • the electric signal generator 130 modulated the seed laser with a sine wave having a modulation frequency f mod : 6.69850 MHz.
  • the degree of modulation by the electric signal generator 130 was 30%.
  • the optical amplifier 120 is an EDFA.
  • the optical multiplexer 210 is a WDM coupler.
  • the REDFA 220 was a thulium-doped fiber amplifier (TDFA) (OFS, TmDF200).
  • the optical demultiplexer 240 is a 50:50 optical coupler.
  • the length L 1 of the resonator 200 was 30.5 m, and the basic resonance frequency of the resonator 200 was 6.7 MHz.
  • the total dispersion of the resonator 200 was ⁇ 1.67 ps 2 .
  • FIG. 17 is a diagram showing the measurement result of the optical spectrum of the pulsed light output from the pulsed light source 10 according to the present embodiment.
  • the optical spectrum was measured with an optical spectrum analyzer (OSA) (ANDO AQ6375) having a resolution of 0.05 nm.
  • OSA optical spectrum analyzer
  • the optical spectrum has a plurality of Kelly sidebands. This indicates that the pulse light source 10 generates a soliton pulse.
  • the spectral width is 0.9 nm.
  • FIG. 18 is a diagram illustrating a measurement result of the pulsed light output from the pulsed light source 10 according to the present embodiment.
  • the pulsed light from the pulsed light source 10 was detected with an InGaAs photodetector (EOT ET-5000, 10 GHz) and measured with an oscilloscope (Agilent DSO1024A).
  • the pulsed light source 10 outputs pulsed light at a repetition frequency of 6.69850 MHz (that is, a frequency equal to the modulation frequency f mod ).
  • Continuous Wave (CW) active mode synchronization was confirmed.
  • FIG. 19 is a diagram illustrating a measurement result of the RF spectrum of the pulsed light output from the pulsed light source 10 according to the present embodiment.
  • the RF spectrum was measured with an RF spectrum analyzer (Agilent E4440A) having a resolution of 1 kHz.
  • a peak with an SN ratio of 70 dB was measured at a frequency of 6.69850 MHz (that is, a frequency equal to the modulation frequency f mod ).
  • FIG. 20 is a diagram illustrating a measurement result of autocorrelation of pulsed light output from the pulsed light source 10 according to the present embodiment.
  • the autocorrelation was measured with a background-free autocorrelator (Femtochrome FR-103HP).
  • the full width at half maximum of the autocorrelation was 8 ps.
  • the pulse width is 5 ps assuming that the waveform of the pulsed light is a hyperbolic secant distribution.
  • pulsed light having a pulse width of 5 ps and a spectral width of 0.9 nm was obtained by CW active mode synchronization.
  • the pulse light source 10 according to the second embodiment is the pulse according to the first embodiment except that the modulation frequency f mod is 13.3970 MHz (that is, the modulation frequency f mod of the first embodiment is twice as high as 6.698850 MHz). The same as the light source 10.
  • FIG. 21 is a diagram illustrating a measurement result of the pulsed light output from the pulsed light source 10 according to the present embodiment.
  • the pulsed light source 10 outputs pulsed light at a repetition frequency of 13.3970 MHz (that is, a frequency equal to the modulation frequency f mod ).
  • f mod the modulation frequency
  • the pulse light source 10 according to the third embodiment is the same as the pulse light source 10 according to the first embodiment except for the following points.
  • the pump laser 110 was a laser having a wavelength of 980 nm.
  • the seed laser was modulated at a modulation frequency f mod : 99.021 MHz.
  • the REDFA 220 was an erbium-doped fiber amplifier (EDFA).
  • the length L 1 of the resonator 200 was 2 km, and the basic resonance frequency of the resonator 200 was 99.021 kHz.
  • the total dispersion of the resonator 200 was ⁇ 0.31 ps 2 .
  • FIG. 22 is a diagram illustrating a measurement result of the optical spectrum of the pulsed light output from the pulsed light source 10 according to the present embodiment. Using Gaussian fitting, the spectral width was 2.26 nm.
  • FIG. 23 is a diagram illustrating a measurement result of autocorrelation of pulsed light output from the pulsed light source 10 according to the present embodiment.
  • the full width at half maximum of the autocorrelation was 1.18 ps, assuming that the waveform of the pulsed light is a hyperbolic secant distribution.
  • FIG. 24 is a diagram illustrating the measurement result of the RF spectrum of the pulsed light output from the pulsed light source 10 according to the present embodiment.
  • a peak with an SN ratio of 53 dB was measured at a frequency of 99.250 MHz (that is, a frequency substantially equal to the modulation frequency f mod ).

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Optics & Photonics (AREA)
  • Lasers (AREA)

Abstract

La présente invention concerne une source de lumière pulsée (10) qui est pourvue de : une source de lumière de pompage (100) ; et un résonateur (200). Le résonateur (200) comporte un amplificateur à fibre dopée aux terres rares (REDFA) (220). La source de lumière de pompage (100) fournit une lumière de pompage au REDFA (220). La lumière de pompage est modulée par un signal de modulation qui a une fréquence de modulation fmod pratiquement équivalente à un multiple entier d'une fréquence de résonance fondamentale f1 du résonateur (200). De manière détaillée, la fréquence de modulation fmod est une fréquence de 95 % à 105 % de l'entier multiple de la fréquence de résonance fondamentale f1 du résonateur (200).
PCT/JP2017/019559 2016-05-27 2017-05-25 Source de lumière pulsée et procédé de génération de lumière pulsée WO2017204299A1 (fr)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TWI649933B (zh) * 2017-12-13 2019-02-01 財團法人工業技術研究院 鎖模光纖雷射裝置
CN109586148A (zh) * 2018-12-25 2019-04-05 武汉孚晟科技有限公司 一种基于主振荡功率放大器结构的脉冲光纤激光器

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09246638A (ja) * 1996-03-01 1997-09-19 Nippon Telegr & Teleph Corp <Ntt> モード同期ファイバレーザ動作安定化法
US20050163170A1 (en) * 2002-03-13 2005-07-28 Oleg Okhotnikov Method for organizing a mode-locked pulse train by pump modulation
US20060187537A1 (en) * 2005-01-20 2006-08-24 Robert Huber Mode locking methods and apparatus
JP2010238865A (ja) * 2009-03-31 2010-10-21 Furukawa Electric Co Ltd:The モード同期レーザ装置
JP2011204834A (ja) * 2010-03-25 2011-10-13 Panasonic Corp ファイバレーザ光源とそれを用いた波長変換レーザ装置

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1926073B (zh) * 2004-03-11 2010-05-12 艾利森电讯公司 用于光学放大器纤维的玻璃

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09246638A (ja) * 1996-03-01 1997-09-19 Nippon Telegr & Teleph Corp <Ntt> モード同期ファイバレーザ動作安定化法
US20050163170A1 (en) * 2002-03-13 2005-07-28 Oleg Okhotnikov Method for organizing a mode-locked pulse train by pump modulation
US20060187537A1 (en) * 2005-01-20 2006-08-24 Robert Huber Mode locking methods and apparatus
JP2010238865A (ja) * 2009-03-31 2010-10-21 Furukawa Electric Co Ltd:The モード同期レーザ装置
JP2011204834A (ja) * 2010-03-25 2011-10-13 Panasonic Corp ファイバレーザ光源とそれを用いた波長変換レーザ装置

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
MARTINEZ ET AL.: "Passive mode-locked lasing by injecting a carbon nanotube-solution in the core of an optical fiber", OPTICS EXPRESS, vol. 18, no. 11, 24 May 2010 (2010-05-24), pages 11008 - 11014, XP055311354 *
YOSHIDA, E. ET AL.: "80-200 GHz erbium doped fibre laser using a rational harmonic mode-locking technique", ELECTRONICS LETTERS, vol. 32, no. 15, 18 July 1996 (1996-07-18), pages 1370 - 1372, XP006005411 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TWI649933B (zh) * 2017-12-13 2019-02-01 財團法人工業技術研究院 鎖模光纖雷射裝置
US10424895B2 (en) 2017-12-13 2019-09-24 Industrial Technology Research Institute Mode-locked fiber laser device
CN109586148A (zh) * 2018-12-25 2019-04-05 武汉孚晟科技有限公司 一种基于主振荡功率放大器结构的脉冲光纤激光器
CN109586148B (zh) * 2018-12-25 2024-04-30 武汉孚晟科技有限公司 一种基于主振荡功率放大器结构的脉冲光纤激光器

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