WO2006099805A1 - Acoustic optical q-modulating method for double-clad fiber laser and apparatus - Google Patents

Acoustic optical q-modulating method for double-clad fiber laser and apparatus Download PDF

Info

Publication number
WO2006099805A1
WO2006099805A1 PCT/CN2006/000469 CN2006000469W WO2006099805A1 WO 2006099805 A1 WO2006099805 A1 WO 2006099805A1 CN 2006000469 W CN2006000469 W CN 2006000469W WO 2006099805 A1 WO2006099805 A1 WO 2006099805A1
Authority
WO
WIPO (PCT)
Prior art keywords
laser
double
acoustic
fiber
clad fiber
Prior art date
Application number
PCT/CN2006/000469
Other languages
French (fr)
Chinese (zh)
Inventor
Mali Gong
Gang Chen
Ping Yan
Qiang Liu
Haitao Zhang
Chen Li
Lei Huang
Changgeng Ye
Original Assignee
Tsinghua University
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 Tsinghua University filed Critical Tsinghua University
Publication of WO2006099805A1 publication Critical patent/WO2006099805A1/en

Links

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
    • H01S3/10—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
    • H01S3/1123—Q-switching
    • H01S3/117—Q-switching using intracavity acousto-optic devices
    • 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
    • H01S3/09—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
    • H01S3/094003—Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light the pumped medium being a fibre
    • H01S3/094007—Cladding pumping, i.e. pump light propagating in a clad surrounding the active core
    • 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
    • H01S3/14—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range characterised by the material used as the active medium
    • H01S3/16—Solid materials
    • H01S3/17—Solid materials amorphous, e.g. glass
    • H01S3/176—Solid materials amorphous, e.g. glass silica or silicate glass

Definitions

  • the present invention relates to an acousto-optic Q-switching method and apparatus for a double-clad fiber laser, and belongs to the field of laser technology.
  • BACKGROUND OF THE INVENTION The working principle of a common acousto-optic Q-switch is: a transducer converts radio frequency input energy into ultrasonic waves, and ultrasonic waves propagate in an acousto-optic medium (for ⁇ ⁇ ⁇ ⁇ laser, fused silica is a kind of acousto-optic medium)
  • the traveling wave field can also reflect on the surface of the opposite medium to form a standing wave field.
  • the periodic intensity distribution of the acoustic wave field causes the periodic distribution of the refractive index of the optical medium, thereby transmitting
  • the light forms a phase grating that changes the direction of propagation of a portion of the light.
  • this loss is large enough (i.e., the quality factor Q of the cavity is sufficiently small), the formation of the oscillating laser at this time can be prevented.
  • the general-purpose double-clad fiber laser Q-switching method follows the traditional Q-switching switch, and the oscillating laser in the fiber is collimated and then passed through the acousto-optic Q switch, and then coupled back into the fiber. Therefore, the insertion loss is large, generally greater than 2 dB.
  • the object of the present invention is to provide an acousto-optic Q-switching method and apparatus for a double-clad fiber laser to overcome the shortcomings of the prior art, and directly implement the acousto-optic Q-switch on a double-clad fiber. Greatly reduce the insertion loss caused by traditional technology.
  • the acousto-optic Q-switching method for a double-clad fiber laser proposed by the present invention directly uses a quartz fiber of a double-clad fiber laser as an acousto-optic medium to form an acoustic standing wave field or a traveling wave field in a double-clad fiber.
  • the refractive index of the quartz in the fiber will be correspondingly changed periodically to form a phase grating.
  • the oscillating laser propagating in the gain core will be diffracted under the action of the phase grating, which will deflect the transmission direction and get rid of the gain core.
  • the waveguide is bound to become a leakage wave.
  • the leakage wave is equivalent to the transmission loss of the waveguide.
  • the acousto-optic Q-switching device for a double-clad fiber laser proposed by the invention comprises a radio frequency excited ultrasonic transducer, an acoustic propagation medium and an acoustic reflection interface or an acoustic absorber, and the 'acoustic propagation medium is placed at a frequency Between the ultrasonic transducer and the acoustic reflection interface or the sound absorber; the double-clad fiber of the Q-switched laser is placed in the acoustic propagation medium.
  • the device may further comprise an acoustic matching glue; the acoustic matching glue is placed in the acoustic propagation medium, and the double-clad fiber of the Q-switched laser is placed in the acoustic matching glue.
  • the double-clad fiber described in the above apparatus may be linear or curved, and its curved radius of curvature is close to the minimum radius of curvature of the fiber. ⁇ Compared with the prior art, the invention has the following advantages and outstanding effects:
  • the acousto-optic Q-switching method and device for the double-clad fiber laser proposed by the invention do not need to output, collimate and couple the laser into the acousto-optic Q-switch by the double-clad fiber compared with the prior art.
  • the acousto-optic Q-switch is directly implemented on the double-clad fiber, thus greatly reducing the insertion loss caused by the conventional technology.
  • the gain of a fiber laser is very high, and it is necessary to provide a large loss if the loss of the oscillating laser is prevented by increasing the loss.
  • the invention directly uses the optical fiber of the double-clad fiber laser as an acousto-optic medium,
  • the oscillating laser in a part of the double-clad fiber laser is separated from the gain core of the double-clad fiber and enters the pump cladding, which greatly reduces the double-clad fiber laser.
  • the gain that can be obtained by this part of the laser increases the waveguide transmission loss of this part of the laser, thereby preventing the formation of the oscillating laser at this time.
  • FIG. 1 is a schematic structural view of a double-clad fiber according to the present invention.
  • FIG. 2 is a schematic diagram showing the principle of an acousto-optic Q-switching method for a double-clad fiber laser according to the present invention
  • FIG. 4 is a schematic structural view of a second embodiment provided by the present invention
  • FIG. 6 is a schematic structural view of a fourth embodiment provided by the present invention.
  • 1 is the gain core
  • 2 is the pump cladding
  • 3 is the outer cladding
  • 4 is the oscillating laser
  • 5 is the pumping light
  • 6 is the phase grating
  • 7 is the leakage wave
  • 8 is the RF excitation Ultrasonic transducer
  • 9 is the acoustic reflection interface or sound absorber
  • 10 is the acoustic propagation medium
  • 11 is the acoustic matching glue
  • 12 is the double-clad fiber.
  • the sound and light Q-switching method for the double-clad fiber optic chopper proposed by the present invention is as shown in FIG. 2 .
  • the quartz fiber of the double-clad fiber laser (the structure is shown in Figure 1) is directly used as an acousto-optic medium to form an acoustic standing wave field or a traveling wave field in the double-clad fiber, which will cause the refractive index of quartz in the fiber to be generated.
  • Corresponding periodic changes form a phase grating (6).
  • the oscillating laser (4) propagating in the gain core (1) will be diffracted by the phase grating (6), causing the transmission direction to be deflected and deviated from the gain.
  • the waveguide of the core (1) is bound to become a leaky wave (7), which is equivalent to the waveguide transmission loss, preventing the oscillating laser
  • the fiber laser is in a low Q state; the acoustic field disappears, the phase grating in the fiber
  • the acousto-optic Q-switching device for a double-clad fiber laser proposed by the present invention has a structure as shown in FIG. 3, and includes an RF-excited ultrasonic transducer (8), an acoustic propagation medium (10), and an acoustic reflection interface or sound.
  • the absorber (9); the acoustic propagation medium (10) is placed between the frequency-excited ultrasonic transducer (8) and the acoustic reflection interface or the sound absorber (9); the double-clad fiber of the Q-switched laser ( 12) Place in the sound propagation medium (10).
  • the above device may further comprise an acoustic matching glue (11).
  • the acoustic matching glue (11) is placed in the acoustic propagation medium (10), and the double-clad fiber (12) of the Q-switched laser is placed.
  • the double-clad fiber described in the above device may be linear, as shown in FIG. 5 and FIG. 6, and may also be curved. As shown in FIG. 3 and FIG. 4, the radius of curvature of the curve is close to the minimum radius of curvature of the fiber. .
  • the fiber structure of the double-clad fiber laser consists of a gain core (1), a pump cladding (2) and an outer cladding (3) (as shown in Figure 1), and an oscillating laser (4) in the gain core (1).
  • the pump light (5) is transmitted in the pump cladding (2).
  • the numerical aperture of the gain core (1) is small as long as the oscillating laser (4) in a part of the double-clad fiber laser is separated.
  • the gain core (1) of the double-clad fiber enters the pump cladding (2), which can greatly reduce the gain that can be obtained by the laser in the double-clad fiber laser at this time, and increase the waveguide transmission of the laser.
  • the transmission loss prevents the formation of the oscillating laser at this time.
  • the invention directly uses the quartz fiber of the double-clad fiber laser as an acousto-optic medium to form an acoustic standing wave field or a traveling wave field in the double-clad fiber, which will cause a corresponding periodic change of the refractive index of the quartz in the fiber, forming Phase grating (6).
  • the oscillating laser (4) propagating in the gain core (1) will be diffracted by the phase grating (6) to deflect the transmission direction and break away from the waveguide of the gain core (1) to become a leaky wave ( 7).
  • the sound and light Q-switching of the double-clad fiber laser can be realized by generating and removing the acoustic wave field with a certain repetition frequency and duty ratio.
  • the double-clad fiber can pass through the acoustic wave field in a straight line or curve according to the turn-on/turn-off extinction ratio requirement of the acousto-optic Q-switching method.
  • the present invention also provides an acousto-optic Q-switching device for a double-clad fiber laser comprising an RF-excited ultrasonic transducer (8) and an acoustic reflection interface or an acoustic absorber (9) Ultrasonic resonator, between the two, using a combination of acoustic propagation medium (10) or acoustic propagation medium (10) and acoustic matching glue (11) filled around the double-clad fiber in the sound field to cure the double cladding Optical fiber (12).
  • a double-clad fiber as an acousto-optic medium passes through it in a straight line or curve.

Abstract

In the acoustic optical Q-modulating method, quartz optical fiber of double-clad fiber laser is used as acoustic optic medium directly. Stationary field of sound wave or traveling wave field is formed in the medium so as to form phasegrating. Deflection of transmitting direction of oscillated laser occurred caused by diffraction under effect of the phase grating is as a leaking wave. The leaking wave prevents forming oscillated laser. Thus, laser of optical fiber is in state of low Q value. When traveling wave field is disappeared, laser is in state of high Q value. The acoustic optical Q switch includes a radio frequency excited ultrasonic transducer, medium for sound propagation, sound reflection interface or body of sound absorption. The medium for sound propagation is placed between the transducer and the interface or body of sound absorption. The double-clad fiber is in medium for sound propagation. The acoustic opticical Q switch is realized in coated fiber directly so as to lower insertion loss.

Description

用于双包层光纤激光器的声光调 Q方法及其装置 技术领域- 本发明涉及一种用于双包层光纤激光器的声光调 Q方法及其装置， 属于激 光技术领域。 背景技术： 普通声光 Q开关的工作原理是： 换能器将射频输入能量转换为超声波， 超 声波在声光介质 （对 ΐ μ πΐ激光， 熔融石英是声光介质的一种） 中传播 （可以是 行波场也可以在对面介质表面反射形成驻波场）， 由于声光介质的声光效应， 声 波场的周期性强弱分布引起了光学介质的折射率的周期性分布，从而对其中传输 的光形成一位相光栅， 使一部分光的传播方向产生 变。 对于振荡激光来说， 就 成为损耗。 只要这个损耗足够大 （即谐振腔的品质因数 Q值足够小） 就能阻止 此时的振荡激光形成。 当突然撤除射频输入能量， 没有超声波产生， 声光介质中 的位相光栅消失， 谐振腔的品质因数 Q值突然升高， 振荡激光产生一个调 Q脉 冲输出。 现在通用的双包层光纤激光器调 Q方法是沿用传统调 Q开关， 将光纤中的 振荡激光准直后通过声光 Q开关， 然后再耦合回光纤中去。 因此插入损耗很大， 一般大于 2dB。 至今， 还没有出现直接用于双包层光纤激光器的， 无需将光纤激 光准直、 耦合的调 Q方法与装置。 发明内容： 本发明的目的是提出一种用于双包层光纤激光器的声光调 Q方法及其装置， 以克服已有技术的缺点， 直接将声光 Q开关在双包层光纤上实现， 大大减小传 统技术带來的插入损耗。 本发明提出的用于双包层光纤激光器的声光调 Q方法， 将双包层光纤激光 器的石英光纤直接作为声光介质，在双包层光纤中形成声波驻波场或行波场，这 将使光纤中石英的折射率产生相应的周期性变化，形成位相光栅，在增益纤芯中 传播的振荡激光在位相光栅的作用下将发生衍射， 使传输方向发生偏折，脱离增 益纤芯的波导束缚， 成为泄漏波， 该泄漏波等效为波导传输损耗， 阻止振荡激光 的形成， 则光纤激光器处于低 Q值状态； 声波场消失， 光纤中的位相光栅随即 消失， 光纤激光器处于高 Q值状态。 本发明提出的用于双包层光纤激光器的声光调 Q装置， 包括射频激励超声 换能器、声传播介质和声反射界面或声吸收体 ·, 所述的 '声传播介质置于频徼励超 声换能器和声反射界面或声吸收体之间；被调 Q激光器的双包层光纤置于声传播 介质中。 上述装置还可包括声匹配胶； 所述的声匹配胶置于声传播介质中， 被调 Q 激光器的双包层光纤置于声匹配胶中。 上述装置中所述的双包层光纤可以是直线的， 也可以是弯曲的， 其弯曲的曲 率半径接近光纤的最小曲率半径。 · 本发明与现有技术相比， 具有以下优点及突出效果： · BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acousto-optic Q-switching method and apparatus for a double-clad fiber laser, and belongs to the field of laser technology. BACKGROUND OF THE INVENTION The working principle of a common acousto-optic Q-switch is: a transducer converts radio frequency input energy into ultrasonic waves, and ultrasonic waves propagate in an acousto-optic medium (for ΐ μ π ΐ laser, fused silica is a kind of acousto-optic medium) The traveling wave field can also reflect on the surface of the opposite medium to form a standing wave field. Due to the acousto-optic effect of the acousto-optic medium, the periodic intensity distribution of the acoustic wave field causes the periodic distribution of the refractive index of the optical medium, thereby transmitting The light forms a phase grating that changes the direction of propagation of a portion of the light. For an oscillating laser, it becomes a loss. As long as this loss is large enough (i.e., the quality factor Q of the cavity is sufficiently small), the formation of the oscillating laser at this time can be prevented. When the RF input energy is suddenly removed, no ultrasonic waves are generated, the phase grating in the acousto-optic medium disappears, the quality factor Q of the cavity suddenly rises, and the oscillating laser produces a Q-switched pulse output. Nowadays, the general-purpose double-clad fiber laser Q-switching method follows the traditional Q-switching switch, and the oscillating laser in the fiber is collimated and then passed through the acousto-optic Q switch, and then coupled back into the fiber. Therefore, the insertion loss is large, generally greater than 2 dB. Up to now, there has not been a Q-switching method and device that is directly used for double-clad fiber lasers without laser alignment and coupling. SUMMARY OF THE INVENTION The object of the present invention is to provide an acousto-optic Q-switching method and apparatus for a double-clad fiber laser to overcome the shortcomings of the prior art, and directly implement the acousto-optic Q-switch on a double-clad fiber. Greatly reduce the insertion loss caused by traditional technology. The acousto-optic Q-switching method for a double-clad fiber laser proposed by the present invention directly uses a quartz fiber of a double-clad fiber laser as an acousto-optic medium to form an acoustic standing wave field or a traveling wave field in a double-clad fiber. The refractive index of the quartz in the fiber will be correspondingly changed periodically to form a phase grating. The oscillating laser propagating in the gain core will be diffracted under the action of the phase grating, which will deflect the transmission direction and get rid of the gain core. The waveguide is bound to become a leakage wave. The leakage wave is equivalent to the transmission loss of the waveguide. When the formation of the oscillating laser is prevented, the fiber laser is in a low Q state. When the acoustic field disappears, the phase grating in the fiber disappears, and the fiber laser is at a high Q value. status. The acousto-optic Q-switching device for a double-clad fiber laser proposed by the invention comprises a radio frequency excited ultrasonic transducer, an acoustic propagation medium and an acoustic reflection interface or an acoustic absorber, and the 'acoustic propagation medium is placed at a frequency Between the ultrasonic transducer and the acoustic reflection interface or the sound absorber; the double-clad fiber of the Q-switched laser is placed in the acoustic propagation medium. The device may further comprise an acoustic matching glue; the acoustic matching glue is placed in the acoustic propagation medium, and the double-clad fiber of the Q-switched laser is placed in the acoustic matching glue. The double-clad fiber described in the above apparatus may be linear or curved, and its curved radius of curvature is close to the minimum radius of curvature of the fiber. · Compared with the prior art, the invention has the following advantages and outstanding effects:
本发明提出的用于双包层光纤激光器的声光调 Q方法及其装置， 与现有的 技术相比无需将激光由双包层光纤中输出、 准直、 耦合入声光 Q开关， 而是直 接将声光 Q开关在双包层光纤上实现， 因此大大减小了传统技术带来的插入损 耗。 光纤激光器的增益是非常高的，如果只靠增加损耗要阻止振荡激光的形成必 须提供很大的损耗。本项发明将双包层光纤激光器的光纤直接作为声光介质， 使 声光 Q幵关在关断时，将一部分的双包层光纤激光器中的振荡激光脱离双包层光 纤的增益纤芯， 进入泵浦包层传输，在大大降低此时双包层光纤激光器中这部分 激光所能获取的增益的同时增加这部分激光的波导传输损耗，从而阻止此时的振 荡激光形成。如果能将作为声光介质的双包层光纤预先弯曲成接近其最小曲率半 径的曲线还可以提高本声光调 Q方法的开通 /关断消光比。 而当本声光 Q幵关开通时， 光纤中的振荡激光仍然满足全内反射条件， 无 附加插入损耗地通过本发明所述的声光 Q开关。 附图说明： 图 1为本发明所涉及的双包层光纤的结构示意图； 图 2为本发明提供的用于双包层光纤激光器的声光调 Q方法的原理示意图； 图 3为本发明提供的用于双包层光纤激光器的声光 Q开关装置的第一种实施 例的结构示意图； 图 4为本发明提供的的第二种实施例的结构示意图； 图 5为本发明提供的的第三种实施例的结构示意图； 图 6为本发明提供的的第四种实施例的结构示意图。 图 1〜图 6中， 1是增益纤芯， 2是泵浦包层， 3是外包层， 4是振荡激光， 5是泵浦光， 6是位相光栅， 7是泄漏波， 8是射频激励超声换能器， 9是声反射 界面或声吸收体， 10是声传播介质， 11是声匹配胶， 12是双包层光纤。 具体实施方式: 本发明提出的用于双包层光纤潋光器的声光调 Q方法， 其原理如图 2所示。 将双包层光纤激光器的石英光纤（其结构如图 1所示）直接作为声光介质， 在双 包层光纤中形成声波驻波场或行波场，这将使光纤中石英的折射率产生相应的周 期性变化， 形成位相光栅 （6)， 在增益纤芯（1 ) 中传播的振荡激光 （4)在位相 光栅（6) 的作用下将发生衍射， 使传输方向发生偏折， 脱离增益纤芯（1 ) 的波 导束缚， 成为泄漏波 （7)， 该泄漏波 （7) 等效为波导传输损耗， 阻止振荡激光The acousto-optic Q-switching method and device for the double-clad fiber laser proposed by the invention do not need to output, collimate and couple the laser into the acousto-optic Q-switch by the double-clad fiber compared with the prior art. The acousto-optic Q-switch is directly implemented on the double-clad fiber, thus greatly reducing the insertion loss caused by the conventional technology. The gain of a fiber laser is very high, and it is necessary to provide a large loss if the loss of the oscillating laser is prevented by increasing the loss. The invention directly uses the optical fiber of the double-clad fiber laser as an acousto-optic medium, When the sound and light Q is turned off, the oscillating laser in a part of the double-clad fiber laser is separated from the gain core of the double-clad fiber and enters the pump cladding, which greatly reduces the double-clad fiber laser. The gain that can be obtained by this part of the laser increases the waveguide transmission loss of this part of the laser, thereby preventing the formation of the oscillating laser at this time. If the double-clad fiber as an acousto-optic medium can be pre-bent to a curve close to its minimum radius of curvature, the turn-on/turn-off extinction ratio of the present acousto-optic Q-switching method can be improved. When the present sound and light Q is turned off, the oscillating laser in the optical fiber still satisfies the total internal reflection condition, and passes through the acousto-optic Q switch of the present invention without additional insertion loss. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic structural view of a double-clad fiber according to the present invention; FIG. 2 is a schematic diagram showing the principle of an acousto-optic Q-switching method for a double-clad fiber laser according to the present invention; A schematic structural view of a first embodiment of an acousto-optic Q-switching device for a double-clad fiber laser; FIG. 4 is a schematic structural view of a second embodiment provided by the present invention; A schematic structural view of three embodiments; FIG. 6 is a schematic structural view of a fourth embodiment provided by the present invention. In Figure 1 to Figure 6, 1 is the gain core, 2 is the pump cladding, 3 is the outer cladding, 4 is the oscillating laser, 5 is the pumping light, 6 is the phase grating, 7 is the leakage wave, 8 is the RF excitation Ultrasonic transducer, 9 is the acoustic reflection interface or sound absorber, 10 is the acoustic propagation medium, 11 is the acoustic matching glue, and 12 is the double-clad fiber. detailed description: The sound and light Q-switching method for the double-clad fiber optic chopper proposed by the present invention is as shown in FIG. 2 . The quartz fiber of the double-clad fiber laser (the structure is shown in Figure 1) is directly used as an acousto-optic medium to form an acoustic standing wave field or a traveling wave field in the double-clad fiber, which will cause the refractive index of quartz in the fiber to be generated. Corresponding periodic changes form a phase grating (6). The oscillating laser (4) propagating in the gain core (1) will be diffracted by the phase grating (6), causing the transmission direction to be deflected and deviated from the gain. The waveguide of the core (1) is bound to become a leaky wave (7), which is equivalent to the waveguide transmission loss, preventing the oscillating laser
(4) 的形成， 则光纤激光器处于低 Q值状态； 声波场消失， 光纤中的位相光栅(4), the fiber laser is in a low Q state; the acoustic field disappears, the phase grating in the fiber
( 6) 随即消失， 光纤激光器处于高 Q值状态。 本发明提出的用于双包层光纤激光器的声光调 Q装置， 其结构如图 3所示， 包括射频激励超声换能器（8 )、声传播介质（10)和与声反射界面或声吸收体（9 ); 所述的声传播介质 （10) 置于频激励超声换能器 （8 ) 和声反射界面或声吸收体 (9 ) 之间； 被调 Q激光器的双包层光纤 （12) 置于声传播介质 （10) 中。 上述装置还可包括声匹配胶 （11 )， 如图 4和图 6所示， 声匹配胶 （11 ) 置 于声传播介质 （10) 中， 被调 Q激光器的双包层光纤 （12) 置于声匹配胶 （11 ) 中。 上述装置中所述的双包层光纤可以是直线的， 如图 5和图 6所示， 也可以是 弯曲的， 如图 3和图 4所示， 其弯曲的曲率半径接近光纤的最小曲率半径。 以下结合附图， 介绍本发明的工作原理： (6) disappears and the fiber laser is in a high Q state. The acousto-optic Q-switching device for a double-clad fiber laser proposed by the present invention has a structure as shown in FIG. 3, and includes an RF-excited ultrasonic transducer (8), an acoustic propagation medium (10), and an acoustic reflection interface or sound. The absorber (9); the acoustic propagation medium (10) is placed between the frequency-excited ultrasonic transducer (8) and the acoustic reflection interface or the sound absorber (9); the double-clad fiber of the Q-switched laser ( 12) Place in the sound propagation medium (10). The above device may further comprise an acoustic matching glue (11). As shown in Figures 4 and 6, the acoustic matching glue (11) is placed in the acoustic propagation medium (10), and the double-clad fiber (12) of the Q-switched laser is placed. In the sound matching glue (11). The double-clad fiber described in the above device may be linear, as shown in FIG. 5 and FIG. 6, and may also be curved. As shown in FIG. 3 and FIG. 4, the radius of curvature of the curve is close to the minimum radius of curvature of the fiber. . The working principle of the present invention will be described below with reference to the accompanying drawings:
双包层光纤激光器的光纤结构由增益纤芯（1 )、泵浦包层（2)和外包层（3 ) 组成（如图 1所示）， 振荡激光 （4)在增益纤芯 （1 ) 中传输， 泵浦光 （5 )在泵 浦包层 （2) 中传输。 虽然双包层光纤的泵浦包层 （2)数值孔径很大， 但其增益 纤芯 （1 ) 的数值孔径却很小， 只要使一部分的双包层光纤激光器中的振荡激光 (4)脱离双包层光纤的增益纤芯（1 ) , 进入泵浦包层 （2)传输， 就能大大降低 此时双包层光纤激光器中这部分激光所能获取的增益，增加这部分激光的波导传 输损耗， 阻止此时的振荡激光的形成。 本发明将双包层光纤激光器的石英光纤直接作为声光介质，在双包层光纤中 形成声波驻波场或行波场， 这将使光纤中石英的折射率产生相应的周期性变化， 形成位相光栅 （6)。 在增益纤芯 （1 ) 中传播的振荡激光 （4) 在位相光栅 （6) 的作用下将发生衍射， 使传输方向发生偏折， 脱离增益纤芯 （1 ) 的波导束缚， 成为泄漏波（7)。这将大大降低双包层光纤的增益， 或者等效为一种波导传输损 耗， 阻止此时的振荡激光 （4) 的形成， 此时光纤激光器处于低 Q值状态； 当声 波场消失， 光纤中的位相光栅 （6) 也将随即消失， 光纤中的振荡激光无损耗地 通过， 此时光纤激光器处于髙 Q值状态。 以一定重复频率和占空比产生和撤除 声波场， 即可实现双包层光纤激光器的声光调 Q。 在本发明所述方法中， 根据声光调 Q方法的开通 /关断消光比要求， 双包层 光纤可以以直线或曲线穿过声波场。 本发明还提供了一种用于双包层光纤激光器的声光 Q开关装置， 该声光 Q 开关装置含有由射频激励超声换能器（8 )与声反射界面或声吸收体（9)组成的 超声谐振腔， 在两者之间， 用声传播介质（10)或者声传播介质（10 )与填充在 声场内双包层光纤周围的声匹配胶 （11 ) 的组合体固化了双包层光纤 （12)。 作 为声光介质的双包层光纤以直线或曲线穿过其中。 The fiber structure of the double-clad fiber laser consists of a gain core (1), a pump cladding (2) and an outer cladding (3) (as shown in Figure 1), and an oscillating laser (4) in the gain core (1). In the middle transmission, the pump light (5) is transmitted in the pump cladding (2). Although the pumping envelope (2) of the double-clad fiber has a large numerical aperture, the numerical aperture of the gain core (1) is small as long as the oscillating laser (4) in a part of the double-clad fiber laser is separated. The gain core (1) of the double-clad fiber enters the pump cladding (2), which can greatly reduce the gain that can be obtained by the laser in the double-clad fiber laser at this time, and increase the waveguide transmission of the laser. The transmission loss prevents the formation of the oscillating laser at this time. The invention directly uses the quartz fiber of the double-clad fiber laser as an acousto-optic medium to form an acoustic standing wave field or a traveling wave field in the double-clad fiber, which will cause a corresponding periodic change of the refractive index of the quartz in the fiber, forming Phase grating (6). The oscillating laser (4) propagating in the gain core (1) will be diffracted by the phase grating (6) to deflect the transmission direction and break away from the waveguide of the gain core (1) to become a leaky wave ( 7). This will greatly reduce the gain of the double-clad fiber, or equivalent to a waveguide transmission loss, preventing the formation of the oscillating laser (4) at this time, at which time the fiber laser is in a low Q state; when the acoustic field disappears, in the fiber The phase grating (6) will also disappear, and the oscillating laser in the fiber will pass without loss. At this time, the fiber laser is in the 髙Q state. The sound and light Q-switching of the double-clad fiber laser can be realized by generating and removing the acoustic wave field with a certain repetition frequency and duty ratio. In the method of the present invention, the double-clad fiber can pass through the acoustic wave field in a straight line or curve according to the turn-on/turn-off extinction ratio requirement of the acousto-optic Q-switching method. The present invention also provides an acousto-optic Q-switching device for a double-clad fiber laser comprising an RF-excited ultrasonic transducer (8) and an acoustic reflection interface or an acoustic absorber (9) Ultrasonic resonator, between the two, using a combination of acoustic propagation medium (10) or acoustic propagation medium (10) and acoustic matching glue (11) filled around the double-clad fiber in the sound field to cure the double cladding Optical fiber (12). A double-clad fiber as an acousto-optic medium passes through it in a straight line or curve.

Claims

权 利 要 求 Rights request
1、 一种用于双包层光纤激光器的声光调 Q方法， 其特征在于： 将双包层光 纤激光器的石英光纤直接作为声光介质，在双包层光纤中形成声波驻波场或行波 场， 这将使光纤中石英的折射率产生相应的周期性变化， 形成位相光栅， 在增益 纤芯中传播的搌荡激光在位相光栅的作用下将发生衍射： 使传输方向发生偏折， 脱离增益纤芯的波导束缚， 成为泄漏波， 该泄漏波等效为波导传输损耗， 阻止振 荡激光的形成， 则光纤激光器处于低 Q值状态； 声波场消失， 光纤中的位相光 栅随即消失， 光纤激光器处于高 Q值状态。  1. An acousto-optic Q-switching method for a double-clad fiber laser, characterized in that: a quartz fiber of a double-clad fiber laser is directly used as an acousto-optic medium to form an acoustic standing wave field or a line in a double-clad fiber. Wave field, which will cause a corresponding periodic change in the refractive index of quartz in the fiber to form a phase grating. The oscillating laser propagating in the gain core will be diffracted by the phase grating: the transmission direction is deflected. The waveguide that is separated from the gain core is bound to become a leakage wave, which is equivalent to the waveguide transmission loss, prevents the formation of the oscillating laser, and the fiber laser is in a low Q state; the acoustic field disappears, and the phase grating in the fiber disappears, the fiber The laser is in a high Q state.
2、 一种用于双包层光纤激光器的声光调 Q装置， 其特征在于该装置包括射 频激励超声换能器、声传播介质和声反射界面或声吸收体；所述的声传播介质置 于频激励超声换能器和声反射界面或声吸收体之间；被调 Q激光器的双包层光纤 置于声传播介质中。 2. An acousto-optic Q-switching device for a double-clad fiber laser, characterized in that the device comprises a radio frequency excited ultrasonic transducer, an acoustic propagation medium and an acoustic reflection interface or an acoustic absorber; The frequency-excited ultrasonic transducer is coupled between the acoustically reflective interface or the acoustic absorber; the double-clad fiber of the Q-switched laser is placed in the acoustic propagation medium.
3、 如权利要求 2所述的装置， 其特征在于还包括声匹配胶； 所述的声匹配 胶置于声传播介质中， 被调 Q激光器的双包层光纤置于声匹配胶中。 3. Apparatus according to claim 2, further comprising an acoustic matching glue; said acoustic matching glue being placed in the acoustic propagation medium, the double-clad fiber of the Q-switched laser being placed in the acoustic matching glue.
4、 如权利要求 2或 3所述的装置， 其特征在于其中所述的双包层光纤是弯 曲的， 其弯曲的曲率半径接近光纤的最小曲率半径。 4. Apparatus according to claim 2 or claim 3 wherein said double clad fiber is curved with a curved radius of curvature close to the minimum radius of curvature of the fiber.
PCT/CN2006/000469 2005-03-25 2006-03-23 Acoustic optical q-modulating method for double-clad fiber laser and apparatus WO2006099805A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CNB2005100567662A CN100374951C (en) 2005-03-25 2005-03-25 Acoustic optical Q-regulating method for two-clad optical-fiber laser and apparatus
CN200510056766.2 2005-03-25

Publications (1)

Publication Number Publication Date
WO2006099805A1 true WO2006099805A1 (en) 2006-09-28

Family

ID=35706742

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2006/000469 WO2006099805A1 (en) 2005-03-25 2006-03-23 Acoustic optical q-modulating method for double-clad fiber laser and apparatus

Country Status (2)

Country Link
CN (1) CN100374951C (en)
WO (1) WO2006099805A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014148941A1 (en) * 2013-03-20 2014-09-25 Общество С Ограниченной Ответственностью "Лазерспарк" Fibre laser with an ultrashort pulse length

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100428000C (en) * 2007-02-02 2008-10-22 中国电子科技集团公司第二十六研究所 Acousto-optic device for ceramic material acoustic absorption
US20080192780A1 (en) * 2007-02-13 2008-08-14 Fei Luo Q-switched all-fibre laser
CN107193084B (en) * 2017-06-09 2023-06-13 广东省智能机器人研究院 All-glass integrated acousto-optic switch
CN110584570B (en) * 2019-10-12 2022-11-08 深圳大学 All-optical detection endoscopic photoacoustic imaging system

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6008930A (en) * 1997-03-04 1999-12-28 Ando Electric Co., Ltd. Acoustooptical modulator
US6535665B1 (en) * 1998-02-12 2003-03-18 Novera Optics, Inc. Acousto-optic devices utilizing longitudinal acoustic waves
CN2638295Y (en) * 2003-07-29 2004-09-01 中国科学院上海光学精密机械研究所 Belt shaped microchip automatic regulating Q double wrapping optical fibre amplifier
CN1560967A (en) * 2004-03-09 2005-01-05 中国科学院上海光学精密机械研究所 Double-cladding fibre-optical laser

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06283795A (en) * 1993-03-26 1994-10-07 Asahi Glass Co Ltd Acousto-optical q-switch for optical fiber laser
JP2001284691A (en) * 2000-03-29 2001-10-12 Toshiba Corp Q switch fiber laser oscillator
CN1149760C (en) * 2000-09-22 2004-05-12 中国科学院上海光学精密机械研究所 Multi-beam wave-synthesis ware-partitioning apparatus for cladded pumping optical fiber amplifier and laser

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6008930A (en) * 1997-03-04 1999-12-28 Ando Electric Co., Ltd. Acoustooptical modulator
US6535665B1 (en) * 1998-02-12 2003-03-18 Novera Optics, Inc. Acousto-optic devices utilizing longitudinal acoustic waves
CN2638295Y (en) * 2003-07-29 2004-09-01 中国科学院上海光学精密机械研究所 Belt shaped microchip automatic regulating Q double wrapping optical fibre amplifier
CN1560967A (en) * 2004-03-09 2005-01-05 中国科学院上海光学精密机械研究所 Double-cladding fibre-optical laser

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014148941A1 (en) * 2013-03-20 2014-09-25 Общество С Ограниченной Ответственностью "Лазерспарк" Fibre laser with an ultrashort pulse length
RU2540064C2 (en) * 2013-03-20 2015-01-27 Общество с ограниченной ответственностью "ЛазерСпарк Ultrashort pulse fibre laser

Also Published As

Publication number Publication date
CN1710482A (en) 2005-12-21
CN100374951C (en) 2008-03-12

Similar Documents

Publication Publication Date Title
Huang et al. Q-switched all-fiber laser with an acoustically modulated fiber attenuator
US6490078B2 (en) Optical fiber for optical amplifier, optical fiber amplifier and optical fiber laser
US20090213877A1 (en) Fiber laser
WO2006099805A1 (en) Acoustic optical q-modulating method for double-clad fiber laser and apparatus
JPH10284777A (en) Optical fiber laser
WO2005096460A1 (en) Optical fiber amplifier and optical amplifying method employing it, laser oscillating method, laser amplifier and laser oscillator, and laser and laser machining apparatus both employing laser oscillator
Huang et al. Reflectivity-tunable fiber Bragg grating reflectors
JP2006128384A (en) Fiber laser, optical fiber therefor, and laser oscillation method
JPH07318996A (en) Wavelength conversion waveguide type laser device
US6181840B1 (en) Reflectivity-tunable fiber optic reflector
US20090041062A1 (en) Fiber-based tunable laser
WO2006072759A2 (en) Acoustically tuned bragg gratings for dispersion compensation
CN101540470A (en) Laser
TWI358869B (en)
JPH11121836A (en) Laser device
CN109407440B (en) Single-mode high-power amplification device based on large-mode-field optical fiber
CN113555765A (en) Low-power-consumption laser based on acousto-optic Q-switching of loading drive of acoustic field
CN102801090B (en) Long-pulse fiber laser
CN101764347B (en) Acousto-optic modulation laser
WO2020155573A1 (en) High peak power low frequency passive mode-locked ultrafast laser
WO2010075368A1 (en) Side-firing optic fiber tip with length-based beam diameter
US20220236594A1 (en) Double-pass fibre-optic amplifer and optical-device architectures
CN205752978U (en) A kind of high cutting laser instrument
JP3762654B2 (en) Optical device
CN205752966U (en) A kind of laser instrument with Jie's stable resonant cavity

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application
NENP Non-entry into the national phase

Ref country code: DE

WWW Wipo information: withdrawn in national office

Country of ref document: DE

NENP Non-entry into the national phase

Ref country code: RU

WWW Wipo information: withdrawn in national office

Country of ref document: RU

122 Ep: pct application non-entry in european phase

Ref document number: 06722121

Country of ref document: EP

Kind code of ref document: A1

WWW Wipo information: withdrawn in national office

Ref document number: 6722121

Country of ref document: EP