WO2020155249A1 - 一种双频光源 - Google Patents

一种双频光源 Download PDF

Info

Publication number
WO2020155249A1
WO2020155249A1 PCT/CN2019/076148 CN2019076148W WO2020155249A1 WO 2020155249 A1 WO2020155249 A1 WO 2020155249A1 CN 2019076148 W CN2019076148 W CN 2019076148W WO 2020155249 A1 WO2020155249 A1 WO 2020155249A1
Authority
WO
WIPO (PCT)
Prior art keywords
unit
reflection
frequency
dual
light source
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.)
Ceased
Application number
PCT/CN2019/076148
Other languages
English (en)
French (fr)
Inventor
文侨
孙志豪
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.)
Shenzhen University
Original Assignee
Shenzhen 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
Priority claimed from CN201910099908.5A external-priority patent/CN111509546B/zh
Priority claimed from CN201920179007.2U external-priority patent/CN209448211U/zh
Application filed by Shenzhen University filed Critical Shenzhen University
Publication of WO2020155249A1 publication Critical patent/WO2020155249A1/zh
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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
    • 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
    • H01S3/23—Arrangements of two or more lasers not provided for in groups H01S3/02 - H01S3/22, e.g. tandem arrangements of separate active media

Definitions

  • This application belongs to the field of optical technology, and particularly relates to a dual-frequency light source.
  • Precision interferometry mainly uses laser wavelength as a "ruler", and uses the principle of interference to measure various parameters, such as acceleration, displacement, angular displacement, and so on. Since the wavelength of light is on the order of nm, its resolution accuracy is unmatched by electrical and magnetic components.
  • the laser interferometer has been widely used in the field of precision and ultra-precision length measurement due to its unique advantages of large measurement range, high resolution and high measurement accuracy.
  • the lasers mainly used in laser interference are single-frequency lasers and dual-frequency lasers.
  • the laser measuring instrument used earlier is a single-frequency interferometer based on a single-frequency laser, but the interferometer is more severely affected by environmental factors, especially when the measurement environment is harsh and the measurement distance is long. The main reason is that it generates a direct current signal.
  • the single-frequency interferometer is largely limited by the drift of the DC amplifier, the sensitivity of the optical receiver and the fluctuation of the laser power during measurement, the single-frequency laser interferometer is difficult to use in high-precision measurement.
  • the dual-frequency laser interferometer developed on the basis of the single-frequency laser interferometer is a heterodyne interferometer. Its most notable feature is the use of carrier technology to convert the measured physical quantity information into a frequency modulation or amplitude modulation signal, which overcomes the common
  • the single-frequency interferometer measures the DC drift of the signal. It has many advantages such as low signal noise, resistance to environmental interference, and allows multi-channel multiplexing of light sources. It is widely used in advanced manufacturing and nanotechnology fields as distance measurement, speed measurement, and vibration measurement. , Shape measurement, real-time position measurement and control, etc.
  • the dual-frequency lasers currently in use mainly include Zeeman dual-frequency lasers, dual-longitudinal-mode dual-frequency lasers, and the birefringent dual-frequency laser proposed by the research group of Professor Zhang Shulian of Tsinghua University.
  • Zeeman dual-frequency lasers use the Zeeman effect, which refers to a phenomenon in which the spectral lines emitted by the light source will split if the light source is placed in a magnetic field.
  • Zeeman dual-frequency laser output frequency difference is generally below 1MHz, generally not used for high-speed precision laser heterodyne interferometry.
  • Dual longitudinal mode lasers can output lasers with two longitudinal mode frequencies in a laser resonator by controlling the cavity length of the laser.
  • the longitudinal mode frequency difference can reach 600MHz-1GHz (the corresponding laser tube length is 150mm-250mm).
  • the birefringent dual-frequency laser is a single longitudinal mode laser resonator, inserting a birefringent optical element such as quartz crystal, calcite, etc., so that the laser in the cavity is split into o light and e with different optical cavity lengths Light, the output of the two orthogonal linearly polarized dual-frequency laser oscillations, the frequency difference is between 3-40MHz, and the required frequency difference can be obtained by adjusting the stress of the birefringent crystal.
  • the common feature is that the laser frequency is more difficult to tune, and the frequency difference adjustment range is relatively limited.
  • the frequency difference of Zeeman can only be adjusted in a relatively small range. It can only be adjusted in a relatively large range, while the birefringence can only be adjusted in a certain range in the middle.
  • the effect is not ideal, and the light of two frequencies is orthogonally polarized, and the polarization state needs to be corrected before it can be used for interference. Therefore, it is necessary to develop a dual-frequency light source with a simpler tuning method and a larger tuning range.
  • the purpose of this application is to provide a dual-frequency light source, including but not limited to solving the technical problem of a small tuning range of a traditional dual-frequency light source.
  • a dual-frequency light source including
  • the first resonant cavity is used to generate a tunable first single-frequency laser
  • the second resonant cavity is used to generate a tunable second single frequency laser
  • the first resonant cavity includes:
  • Gain medium used to generate excitation light by pump light excitation
  • the common reflection filtering unit and the first reflection filtering unit are used to reflect and filter the excitation light, and the filtering ranges of the common reflection filtering unit and the first reflection filtering unit partially overlap to realize narrowband filtering. Obtain the first single-frequency laser;
  • the second resonant cavity includes:
  • the gain medium is used to generate excitation light through pump light excitation
  • the common reflection filtering unit and the second reflection filtering unit are used to reflect and filter the excitation light, and the filtering ranges of the common reflection filtering unit and the second reflection filtering unit partially overlap to achieve narrowband filtering, Used to obtain the second single frequency laser.
  • the dual-frequency light source provided by the present application has the following beneficial effects: through the common reflection filter unit and the first reflection filter unit, an extremely narrow linewidth single-frequency laser output is realized based on deviation filtering, and the common reflection filter unit and the second reflection filter unit are based on Deviation filtering realizes extremely narrow linewidth single-frequency laser output, and obtains the first single-frequency laser and the second single-frequency laser. Furthermore, dual-frequency output is realized on the basis of obtaining extremely narrow linewidth laser by deviation filtering.
  • FIG. 1 is a single longitudinal mode operation principle diagram of a first resonant cavity and a second resonant cavity of a dual-frequency light source provided by an embodiment of the present application;
  • FIG. 2 is a principle diagram of adjusting the center wavelength of the first single-frequency laser of the dual-frequency light source according to an embodiment of the present application
  • FIG. 3 is a schematic diagram of bandwidth adjustment of a first single-frequency laser of a dual-frequency light source provided by an embodiment of the present application;
  • FIG. 4 is a structural diagram of a dual-frequency light source provided by the first embodiment of the present application.
  • FIG. 5 is a structural diagram of another dual-frequency light source provided by the first embodiment of the present application.
  • FIG. 6 is a structural diagram of a dual-frequency light source provided by a second embodiment of the present application.
  • Fig. 7 is a structural diagram of a dual-frequency light source provided by a third embodiment of the present application.
  • FIG. 8 is a structural diagram of a dual-frequency light source provided by the fourth embodiment and the eighth embodiment of the present application.
  • FIG. 9 is a structural diagram of a dual-frequency light source provided by a fifth embodiment of the present application.
  • FIG. 10 is a structural diagram of a dual-frequency light source provided by a sixth embodiment of the present application.
  • FIG. 11 is a structural diagram of a dual-frequency light source provided by a seventh embodiment of the present application.
  • FIG. 12 is a structural diagram of a common reflection filtering unit, a first reflection filtering unit, and a second reflection filtering unit of a dual-frequency light source according to an embodiment of the present application;
  • FIG. 13 is another structural diagram of the common reflection filter unit, the first reflection filter unit, and the second reflection filter unit of the dual-frequency light source provided by an embodiment of the present application.
  • an embodiment of the present application provides a dual-frequency light source, including a pumping unit 10 for outputting pump light; a first resonant cavity for generating a tunable first single-frequency laser; Two resonant cavities, used to generate tunable second single frequency laser.
  • the first resonant cavity includes: a gain medium 20 for generating excitation light after being excited by pump light; a common reflection filtering unit 30 and a first reflection filtering unit 40 for reflecting and filtering laser light, and common reflection filtering
  • the filtering ranges of the unit 30 and the first reflection filtering unit 40 partially overlap to achieve ultra-narrowband filtering, thereby obtaining the first single-frequency laser
  • the second resonant cavity includes: the gain medium 20, which is used to generate laser light after excitation by the pump light;
  • the reflection filtering unit 30 and the second reflection filtering unit 60 are used to reflect and filter the laser light.
  • the filtering ranges of the common reflection filtering unit 30 and the second reflection filtering unit 60 partially overlap to achieve ultra-narrowband filtering, thereby obtaining the second single Frequency laser.
  • the “reflection” refers to the reflection of light intensity
  • the “filtering” refers to the filtering of frequency.
  • the common reflection filter unit 30 and the first reflection filter unit 40 form two ends of the first resonant cavity, and the common reflection filter unit 30 and the second reflection filter unit 60 form the second resonant cavity.
  • the common reflection filter unit 30 is a common part of the first resonant cavity and the second resonant cavity, and the gain medium 20 is also a common part of the first resonant cavity and the second resonant cavity.
  • the common reflection filter unit 30 can reflect the light intensity and filter the laser frequency
  • the first reflection filter unit 40 can reflect the light intensity and filter the laser frequency.
  • the first reflection filter unit 40 and the common reflection filter unit 30 have filter bandwidths L1 and L0, respectively, and the filter bandwidths L1 and L0 have an overlapping frequency band L10.
  • the overlapping frequency band L10 has a smaller bandwidth and can be based on the The deviation filter obtains the single longitudinal mode resonance, and obtains the first single frequency laser.
  • the second reflection filter unit 60 and the common reflection filter unit 30 have filter bandwidths L2 and L0, respectively.
  • the filter bandwidths L2 and L0 have an overlapping frequency band L20, which has a smaller bandwidth, and thus can obtain single longitudinal mode resonance. Obtain the second single-frequency laser.
  • the dual-frequency light source uses the common reflection filter unit 30 and the first reflection filter unit 40 to achieve extremely narrow linewidth single-frequency laser output based on deviation filtering, the first single-frequency laser and the second single-frequency laser, and then Based on the deviation filtering to obtain the extremely narrow linewidth laser, the dual-frequency output is realized, and the output laser is stable.
  • the dual-frequency light source further includes a tuning unit.
  • the tuning unit (the first tuning unit 50) is connected to the first reflection filter unit 40 for adjusting the center wavelength and/or bandwidth of the first reflection filter unit 40 , To obtain the tunable first single frequency laser.
  • the tuning unit (the second tuning unit 70) is connected to the second reflection filter unit 60 and is used to adjust the center wavelength and/or bandwidth of the second reflection filter unit 60 to obtain a tunable second single frequency laser.
  • the tuning unit (the third tuning unit 33) is connected to the common reflection filter unit for obtaining the tunable first single-frequency laser and the tunable second single-frequency laser simultaneously.
  • the tuning unit may alternatively be connected to the first reflection filtering unit 40, the second reflection filtering unit 60, and the common reflection filtering unit 30, or may be connected to two filtering units or to three filtering units at the same time.
  • the center wavelength ⁇ 1 of the first reflection filter unit 40 is adjusted by the first tuning unit 50, while the center wavelength ⁇ 0 of the common reflection filter unit 30 is kept unchanged, the center of the first single-frequency laser obtained
  • the wavelength is shifted from ⁇ 101 to ⁇ 102.
  • the first tuning unit 50 is used to adjust the filter bandwidth L1 of the first reflection filter unit 40
  • the third tuning unit 33 is used to adjust the filter bandwidth L0 of the common reflection filter unit 30, the bandwidth of the first single-frequency laser Change from L101 to L102.
  • adjusting the first tuning unit 50 while keeping the common reflection filter unit 30 unchanged can also obtain the tunable first single-frequency laser.
  • adjusting the center wavelength ⁇ 0 and the filter bandwidth L0 of the common reflection filter unit 30 at the same time can make the adjustment of the center wavelength and bandwidth of the first single-frequency laser more flexible and with a larger adjustable range.
  • the center wavelength and bandwidth of the second reflection filter unit 60 through the second tuning unit 70, or further adjust the common reflection filter unit 30 at the same time can be adjusted.
  • the dual-frequency light source provided by the embodiment of the present application further has the following effects:
  • the common reflection filter unit 30 and the first reflection filter unit 40 Through the common reflection filter unit 30 and the first reflection filter unit 40, a very narrow linewidth single-frequency laser output is realized based on deviation filtering, and the first reflection filter unit 40 is adjusted by the first tuning unit 50 to obtain a tunable first single frequency laser output.
  • Frequency laser through the common reflection filter unit 30 and the second reflection filter unit 60, based on deviation filtering to achieve a very narrow linewidth single-frequency laser output, through the second tuning unit 70 to adjust the second reflection filter unit 60 to obtain a tunable
  • the second single-frequency laser realizes dual-frequency output based on the deviation filtering to obtain extremely narrow linewidth laser, and the output laser is stable and easy to tune; and the theoretical frequency difference of the dual-frequency light source is the entire common reflection filter unit
  • the spectrum of 30 can reach more than tens of MHz, with a large tuning range, and has a stronger potential as a detection light source.
  • the deviation filtering method used in the embodiments of the present application to obtain the first single-frequency laser and the second single-frequency laser has the following effects: Compared with the traditional single-frequency light source using narrow-band fiber grating and broadband fiber grating as the cavity mirror, one On the other hand, there is no need to set up extremely narrow-band fiber gratings that are extremely difficult to manufacture, and the bandwidth requirements of the common reflection filter unit 30, the first reflection filter unit 40, and the second reflection filter unit 60 are not high.
  • the narrow filtering range is limited by the requirements, and it can be composed of gratings with lower parameters, which greatly reduces the process difficulty.
  • the reflection bandwidth of the narrow-band grating must be smaller than the longitudinal mode interval.
  • the shorter the cavity length the greater the longitudinal mode interval, and the lower the requirement for narrow-band gratings.
  • the cavity length is shorter.
  • the output power will be lost, and the traditional single-frequency light source has the mutual restriction of narrow-band grating performance and output power.
  • this embodiment does not completely rely on the filtering performance of either end filter unit, that is, it is not necessary to make any filter bandwidth smaller than the longitudinal mode interval. Therefore, the restriction on the cavity length is lifted, and the filtering performance and output power of each reflection filter unit are prevented from mutually restricting each other, and the selection of each reflection filter unit and the design of the resonant cavity are more flexible.
  • the following embodiments 1 to 3 provide several dual-frequency light sources with a straight cavity structure.
  • the dual-frequency light source of the straight cavity structure includes the above-mentioned pump unit 10, gain medium 20, common reflection filter unit 30, first reflection filter unit 40, first tuning unit 50, and second reflection filter unit. 60.
  • the common reflection filter unit 30, the first reflection filter unit 40 and the second reflection filter unit 60 are arranged in a straight line, the gain medium 20 is arranged between the common reflection filter unit 30 and the first reflection filter unit 40; the common reflection filter unit 30 and the first reflection filter unit 40 constitute both ends of the first resonant cavity, the common reflection filter unit 30 and the second reflection filter unit 60 constitute both ends of the second resonant cavity, the first resonant cavity and the second resonant cavity have a common section , That is, the part between the common reflection filtering unit 30 and the first reflection filtering unit 40.
  • the first reflection filter unit 40 includes a first reflection filter waveband region 41 and a first transmission waveband region 42. A part of the energy of the laser light is totally reflected or high in the first reflection filter waveband region 41. Reflection and filtering are used to form a tunable first single-frequency laser. Another part of the energy of the laser is transmitted from the first transmission band region 42 to the second reflection filter unit 60, and is totally reflected by the second reflection filter unit 60 and then again by The first transmission band region 42 transmits to the common reflection filter unit 30 for forming a tunable second single-frequency laser.
  • a third tuning unit 33 can be provided, connected to the common reflection filter unit 30, and a tunable first single-frequency laser and a tunable second single-frequency laser can be simultaneously obtained.
  • the common reflection filter unit 30 adopts a partial reflection filter unit, which is used to partially reflect and filter the laser light in the cavity and output the first single frequency laser light and the second single frequency laser light.
  • a first pump light coupling unit 81 is provided between the pump unit 10 and the common reflection filter unit 30 to couple the pump light from the common reflection filter unit 30 into the first resonant cavity and the second resonant cavity;
  • the common reflection filter unit 30 outputs the first single-frequency laser light and the second single-frequency laser light, which are then output through the first pump light coupling unit 81.
  • the first tuning unit 50, the second tuning unit 70, and the third tuning unit 33 may not be used in this embodiment, and only a dual-frequency laser with a fixed frequency is output.
  • the isolation unit 90 can also be provided in the direction in which the first pump light coupling unit 81 outputs the first single-frequency laser light and the second single-frequency laser light. It is also possible to provide another isolation unit between the pump unit 10 and the first pump light coupling unit 81 to avoid reflection back to the pump source and burn the pump source.
  • the first pump light coupling unit 81 and the isolation can all be connected by optical fibers to realize an all-fiber dual-frequency light source.
  • the pump unit 10 and the first pump light coupling unit 81 may be connected by an optical fiber, and the first pump light coupling unit 81 and the isolation unit 90 may be connected by an optical fiber.
  • the first pump light coupling unit 81 and The common reflection filter unit 30 can transmit light through free space to realize a dual-frequency light source of some optical fibers.
  • the pump unit 10 and the first pump light coupling unit 81 can transmit light through free space, and the first pump light coupling unit 81 and the common reflection filter unit 30 can transmit light through an optical fiber.
  • the coupling unit 81 and the isolation unit 90 may be connected by an optical fiber, or a dual-frequency light source of partial optical fiber may be realized.
  • the common reflection filter unit 30 still adopts a partial reflection filter unit, which is used to partially reflect and filter the laser light in the cavity and output the first single frequency laser and the second single frequency. laser.
  • a second pump light coupling unit 82 is provided in the first resonant cavity or the second resonant cavity to couple the pump light into the first resonant cavity and the second resonant cavity.
  • the pump light enters through the side of the resonator, and the tunable first single-frequency laser and the second single-frequency laser are output through the common reflection filter unit 30.
  • all devices can be connected by all-optical fiber, or a combination of free-space connection and fiber-optic connection, or full-space connection, etc.
  • the public reflection filter unit 30 adopts a total reflection filter unit for total reflection and filtering of the laser; in the first resonant cavity or A third pump light coupling unit 83 is provided in the second resonant cavity for inputting pump light through the side end of the first resonant cavity or the second resonant cavity; it is set in the common part of the first resonant cavity and the second resonant cavity
  • the output unit 100 is used to output the first single-frequency laser and the second single-frequency laser.
  • all devices can be connected by all-optical fiber, or a combination of free-space connection and fiber-optic connection, or full-space connection, etc.
  • the following provides a dual-frequency light source with a ring cavity structure through the fourth to eighth embodiments.
  • the dual-frequency light source includes the above-mentioned pump unit 10, gain medium 20, common reflection filter unit 30,
  • the first reflection filter unit 40, the first tuning unit 50, the second reflection filter unit 60, and the second tuning unit 70 it also includes a fourth pump light coupling unit 84, a first coupler 110, and a second coupler 120
  • the fourth pump light coupling unit 84 has three ports, the first end is connected to the pump unit 10, the second end is directly or indirectly connected to the first coupler 110, and the third end is directly or indirectly connected to the common reflection filter unit 30;
  • the reflection filter unit 40 and the second reflection filter unit 60 are connected in parallel between the first coupler 110 and the second coupler 120, that is, one end of the first reflection filter unit 40 and one end of the second reflection filter unit 60 are directly or indirectly connected together.
  • the common reflection filter unit 30 is connected to the second coupler 120 and Between the third ends of the fourth pump light coupling unit 84, a ring cavity is formed.
  • directly means that no other elements other than the light guide cable are arranged between the two
  • indirect means that other elements other than the light guide cable are also arranged between the two.
  • an output unit 100 is further provided between the third end of the fourth pump light coupling unit 84 and the common reflection filter unit 30. Further, an isolation unit 90 can also be provided in the output direction of the output unit 100.
  • a gain medium 20 is also provided between the second end of the fourth pump light coupling unit 84 and the first coupler 110.
  • the gain medium 20 may also be arranged at other positions in the common section of the first resonant cavity and the second resonant cavity.
  • Other elements may be provided between one end of the first reflection filter unit 40 and one end of the second reflection filter unit 60 and the first coupler 110, the other end of the first reflection filter unit 40 and the other end of the second reflection filter unit 60
  • Other elements can also be arranged between the second coupler 120 and the second coupler 120, as in the eighth embodiment.
  • all devices can be connected by all-optical fiber, or a combination of free-space connection and fiber-optic connection, or full-space connection, etc.
  • the free space connection is adopted, the light path can be deflected by the reflecting mirror to form a ring cavity structure.
  • an isolator may be respectively provided on the two parallel branches between the first coupler 110 and the second coupler 120, and the directions of the two isolators are the same or opposite, that is, the two isolator Clockwise transmission is allowed and counterclockwise transmission is blocked; or counterclockwise transmission is allowed and clockwise transmission is blocked; or one isolator allows clockwise transmission and the other isolator allows counterclockwise transmission.
  • an isolator may also be provided on the common section between the fourth pump light coupling unit 84 and the first coupler 110; or, on the fourth pump light coupling unit 84 and the second coupler There is an isolator on the common section between 120 to prevent the laser from being transmitted back.
  • the fifth embodiment and the fourth embodiment have the same main structure (such as pumping unit 10, gain medium 20, common reflection filtering unit 30, first reflection filtering unit 40, first tuning unit 50, second reflection The filter unit 60, the second tuning unit 70, the fourth pump light coupling unit 84, the first coupler 110 and the second coupler 120 and their connection structure), the difference is that the output unit 100 is arranged in the second coupler 120 And the common reflection filter unit 30. Further, an isolation unit 90 can also be provided in the output direction of the output unit 100.
  • Embodiment 6 is a diagrammatic representation of Embodiment 6
  • the sixth embodiment and the fourth embodiment have the same main structure (such as the pump unit 10, the gain medium 20, the common reflection filter unit 30, the first reflection filter unit 40, the first tuning unit 50, the second reflection The filter unit 60, the second tuning unit 70, the fourth pump light coupling unit 84, the first coupler 110 and the second coupler 120 and their connection structure), the difference is that the first coupler 110 and the second coupling
  • An output unit 100 is respectively provided on the two parallel branches between the converter 120, that is, an output unit 100 is provided close to the first reflection filter unit 40 for outputting the tunable first single-frequency laser, and is provided close to the second reflection filter unit 60
  • the other output unit 100 is used to output a tunable second single frequency laser.
  • an isolation unit 90 may be provided in the output path of each output unit 100.
  • all devices can be connected by all-optical fiber, or a combination of free-space connection and fiber-optic connection, or full-space connection, etc.
  • the free space connection is adopted, the light path can be deflected by the reflecting mirror to form a ring cavity structure.
  • the seventh embodiment and the fourth embodiment have the same main structure (such as pumping unit 10, gain medium 20, common reflection filtering unit 30, first reflection filtering unit 40, first tuning unit 50, second reflection
  • the common reflection filter unit 30 adopts a partial reflection filter unit , It has the function of outputting the first single-frequency laser and the second single-frequency laser and the function of reflection filtering.
  • Embodiment 8 is a diagrammatic representation of Embodiment 8
  • the dual-frequency light source of the ring cavity structure has the basic mechanism described in the fourth embodiment, such as the pump unit 10, the gain medium 20, the common reflection filter unit 30, the first reflection filter unit 40, and the first tuning unit 50.
  • the second reflection filter unit 60, the second tuning unit 70, the fourth pump light coupling unit 84, the first coupler 110 and the second coupler 120 and their connection structure, etc. the difference is that they also include a first circulator 131, the second circulator 132 and the third circulator 133, so as to form the reflection light path of the common reflection filter unit 30, the first reflection filter unit 40, and the second reflection filter unit 60; the first end of the first circulator 131 is connected The first coupler 110, the second end of the first circulator 131 is connected to the first reflection filter unit 40, the third end of the first circulator 131 is connected to the second coupler 120; the first end of the second circulator 132 is connected to the first A coupler 110, the second end of the second circulator 132 is connected to the second reflection filter
  • the common reflection filter unit 30, the first reflection filter unit 40, and the second reflection filter unit 60 can all adopt two structures.
  • the integrated structure for frequency filtering and light intensity reflection of laser light is shown in Fig. 12; secondly, a combined structure of two independent modules is adopted, as shown in Fig. 13.
  • the first reflection filter unit 40 includes a first mirror 43 and is arranged on the The first filter module 44 in the reflection direction of a mirror 43;
  • the second reflection filter unit 60 includes a second mirror 61 and a second filter module 62 arranged in the reflection direction of the second mirror 61;
  • the common reflection filter unit 30 includes The common mirror 31 and the common filter module 32 arranged in the reflection direction of the common mirror 31.
  • first reflection filter unit 40 may adopt an integrated structure at the same time, or a combined structure at the same time, or a part of an integrated structure and a part of a combined structure.
  • the gain medium 20 may be a gain fiber or a block-shaped gain crystal.
  • the Bragg fiber grating can be directly written on the fiber to form a grating cavity mirror, so the compatibility with the doped active fiber is very good, not only the connection loss is very small, but also the complicated optics is avoided.
  • the structure is convenient for the integration and miniaturization of the fiber laser, so that the fiber laser has better stability and reliability, and is especially suitable for workplaces with very harsh environmental conditions. Therefore, in this embodiment, it is preferable to use an integrated grating cavity mirror formed by directly writing Bragg fiber gratings on the optical fiber as the common reflection filter unit 30, the first reflection filter unit 40 and the second reflection filter unit 60, and the structure is compact. , And for a straight cavity, the length of the entire resonant cavity is short, and the light source has a small volume; for a ring cavity, the volume can also be appropriately reduced.

Landscapes

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

Abstract

一种双频光源，包括泵浦单元（10），第一谐振腔，第二谐振腔，第一谐振腔包括增益介质（20），公共反射滤波单元（30）和第一反射滤波单元（40），第二谐振腔包括增益介质（20），公共反射滤波单元（30）和第二反射滤波单元（60），还包括调谐单元，用于调节第一反射滤波单元（40）的中心波长和/或带宽，和/或调节第二反射滤波单元（60）的中心波长和/或带宽，获得可调谐的第一单频激光和可调谐的第二单频激光。基于偏差滤波实现极窄线宽单频激光输出，通过调谐单元获得可调谐的双频激光，输出激光稳定而且调谐简易，调谐范围大，具有更强的作为探测光源的潜力。

Description

一种双频光源
本申请要求于2019年1月31日提交中国专利局，申请号为201910099908.5，发明名称为“一种双频光源”、于2019年1月31日提交中国专利局，申请号为201920179007.2，发明名称为“一种双频光源”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请属于光学技术领域，特别涉及一种双频光源。
 背景技术
激光技术的发展有力的推动了光通信、非线性光学、高分辨光学等领域的发展，尤其在精密干涉测量方面占据了很大优势。精密干涉测量主要以激光波长作为“尺子”，利用干涉原理来测定各种参量，如加速度、位移、角位移等等。由于光波长为nm数量级，因此其分辨精度是电学、磁学元件无法比拟的。激光干涉仪以其特有的大测量范围、高分辨率和高测量精度等优点，在精密和超精密测长领域获得了广泛的应用。激光干涉主要使用的激光器为单频激光器和双频激光器。较早使用的激光测量仪器是以单频激光为基础的单频干涉仪，但该干涉仪受环境因素的影响比较严重,尤其是在测量环境恶劣,测量距离较长时受影响更为突出。主要是因为它产生的是一直流信号,在大距离测量时光能的衰减、空气湍流的存在、背景光强的变化等对激光束的干扰都会使光束发生偏移，不可避免的使激光束强度发生变化，从而导致直流光强和电平的漂移。由于单频干涉仪在测量时很大程度上受直流放大器的漂移、光接收器灵敏度和激光功率起伏的限制，因此单频激光干涉仪在高精度测量中是很难利用的。
在单频激光干涉仪的基础上发展起来的双频激光干涉仪是一种外差干涉仪，其最显著的特点是利用载波技术将被测物理量信息转换成调频或调幅信号，它克服了普通单频干涉仪测量信号直流漂移的问题，具有信号噪声小、抗环境干扰、允许光源多通道复用等诸多优点，被广泛应用于先进制造行业和纳米技术领域作为距离测量、速度测量、振动测量、形貌测量，实时位置测控等。
目前使用的双频激光器主要有塞曼双频激光、双纵模双频激光以及清华大学张书练教授课题组提出的双折射率双频激光。塞曼双频激光利用塞曼效应，该效应是指若把光源放在磁场中，光源发出的谱线将发生分裂的这种现象。塞曼双频激光器输出频差一般在1MHz以下，一般不用于高速精密激光外差干涉测量。双纵模激光器是通过控制激光器的腔长等，实现在一个激光谐振腔中输出两个纵模频率的激光，纵模频差可达600MHz-1GHz(对应的激光管长度为150mm-250mm)。双折射双频激光为在单纵模激光谐振腔内，插入一块具有双折射效应的光学元件如石英晶体、方解石等等，使得腔内的激光分裂成具有不同光学谐振腔长的o光和e光，这两束正交线偏振的双频激光振荡输出，其频差为3-40MHz之间，可通过调节双折射晶体的应力得到所需的频差。
在上述的三种双频激光器中，其共同特点为激光频率调谐难度较大，且频率差调整范围较有限，比如塞曼的频差只能在比较小的范围调节，双纵模激光频差只能在比较大的范围调节，而双折射双频只能在中间某个范围调节，效果并不理想，且两个频率的光正交偏振，需要进行偏振态校正后才能用于干涉。因此需要研发一种调谐方式更为简单，调谐范围更大的双频光源。
 技术问题
本申请的目的在于提供一种双频光源，包括但不限于解决传统双频光源调谐范围小的技术问题。
 技术解决方案
为解决上述技术问题，本申请采用的技术方案是：一种双频光源，包括
泵浦单元，用于输出泵浦光；
第一谐振腔，用于产生可调谐的第一单频激光；
第二谐振腔，用于产生可调谐的第二单频激光；
所述第一谐振腔包括：
增益介质，用于经泵浦光激发产生激发光；
公共反射滤波单元和第一反射滤波单元，用于对所述激发光进行反射和滤波，所述公共反射滤波单元和所述第一反射滤波单元的滤波范围部分重叠，以实现窄带滤波，用于获得第一单频激光；
所述第二谐振腔包括：
所述增益介质，用于经泵浦光激发产生激发光；
所述公共反射滤波单元和第二反射滤波单元，用于对所述激发光进行反射和滤波，所述公共反射滤波单元和所述第二反射滤波单元的滤波范围部分重叠，以实现窄带滤波，用于获得第二单频激光。
 有益效果
本申请提供的双频光源具有如下有益效果：通过公共反射滤波单元和第一反射滤波单元，基于偏差滤波实现极窄线宽单频激光输出，通过公共反射滤波单元和第二反射滤波单元，基于偏差滤波实现极窄线宽单频激光输出，获得第一单频激光和第二单频激光。进而在偏差滤波获得极窄线宽激光的基础上实现了双频输出。
 附图说明
为了更清楚地说明本发明实施例中的技术方案，下面将对实施例或现有技术描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其它的附图。
图1是本申请实施例提供的双频光源的第一谐振腔和第二谐振腔的单纵模运转原理图；
图2是本申请实施例提供的双频光源的第一单频激光的中心波长调节原理图；
图3是本申请实施例提供的双频光源的第一单频激光的带宽调节原理图；
图4是本申请第一实施例提供的一种双频光源的结构图；
图5是本申请第一实施例提供的另一种双频光源的结构图；
图6是本申请第二实施例提供的双频光源的结构图；
图7是本申请第三实施例提供的双频光源的结构图；
图8是本申请第四实施例和第八实施例提供的双频光源的结构图；
图9是本申请第五实施例提供的双频光源的结构图；
图10是本申请第六实施例提供的双频光源的结构图；
图11是本申请第七实施例提供的双频光源的结构图；
图12是本申请实施例提供的双频光源的公共反射滤波单元、第一反射滤波单元和第二反射滤波单元的一种结构图；
图13是本申请实施例提供的双频光源的公共反射滤波单元、第一反射滤波单元和第二反射滤波单元的另一种结构图。
 本发明的实施方式
为了使本申请的目的、技术方案及优点更加清楚明白，以下结合附图及实施例，对本申请进行进一步详细说明。应当理解，此处所描述的具体实施例仅用以解释本申请，并不用于限定本申请。
需说明的是，当部件被称为“固定于”或“设置于”另一个部件，它可以直接或者间接位于该另一个部件上。当一个部件被称为“连接于”另一个部件，它可以是直接或者间接连接至该另一个部件上。术语“上”、“下”、“左”、“右”、“前”、“后”、“竖直”、“水平”、“顶”、“底”、“内”、“外”等指示的方位或位置为基于附图所示的方位或位置，仅是为了便于描述，不能理解为对本技术方案的限制。术语“第一”、“第二”仅用于便于描述目的，而不能理解为指示或暗示相对重要性或者隐含指明技术特征的数量。“多个”的含义是两个或两个以上，除非另有明确具体的限定。
为了说明本申请所述的技术方案，以下结合具体附图及实施例进行详细说明。
请参阅图4和图5，本申请实施例提供一种双频光源，包括泵浦单元10，用于输出泵浦光；第一谐振腔，用于产生可调谐的第一单频激光；第二谐振腔，用于产生可调谐的第二单频激光。具体地，第一谐振腔包括：增益介质20，用于经过泵浦光激发后产生激发光；公共反射滤波单元30和第一反射滤波单元40，用于对激光进行反射和滤波，公共反射滤波单元30和第一反射滤波单元40的滤波范围部分重叠，以实现超窄带滤波，从而获得第一单频激光；第二谐振腔包括：增益介质20，用于泵浦光激发后产生激光；公共反射滤波单元30和第二反射滤波单元60，用于对激光进行反射和滤波，公共反射滤波单元30和第二反射滤波单元60的滤波范围部分重叠，以实现超窄带滤波，从而获得第二单频激光。在该实施例中，所述“反射”是指对光强的反射，所述“滤波”是指对频率的滤波。
具体地，该双频激光光源中，公共反射滤波单元30和第一反射滤波单元40构成了第一谐振腔的两端，公共反射滤波单元30和第二反射滤波单元60构成了第二谐振腔的两端，公共反射滤波单元30为第一谐振腔和第二谐振腔的共用部分，增益介质20也为第一谐振腔和第二谐振腔的共用部分。在第一谐振腔中，公共反射滤波单元30能够对光强进行反射，并对激光频率进行滤波，第一反射滤波单元40能够对光强进行反射，并对激光频率进行滤波。参见图1，第一反射滤波单元40和公共反射滤波单元30分别具有滤波带宽L1和L0，滤波带宽L1和L0具有交叠频带L10，该交叠频带L10具有较小的带宽，进而可以基于该偏差滤波获得单纵模谐振，获得第一单频激光。第二反射滤波单元60和公共反射滤波单元30分别具有滤波带宽L2和L0，滤波带宽L2和L0具有交叠频带L20，该交叠频带L20具有较小的带宽，进而可以获得单纵模谐振，获得第二单频激光。
本申请实施例提供的双频光源通过公共反射滤波单元30和第一反射滤波单元40，基于偏差滤波实现极窄线宽单频激光输出，第一单频激光和第二单频激光，进而在偏差滤波获得极窄线宽激光的基础上实现了双频输出，并且输出激光稳定。
进一步地，该双频光源还包括调谐单元，具体可以是，调谐单元（第一调谐单元50）连接于第一反射滤波单元40，用于调节第一反射滤波单元40的中心波长和/或带宽，以获得可调谐的第一单频激光。还可以是，调谐单元（第二调谐单元70）连接于第二反射滤波单元60，用于调节第二反射滤波单元60的中心波长和/或带宽，以获得可调谐的第二单频激光。还可以是，调谐单元（第三调谐单元33）连接于公共反射滤波单元，用于同时获得可调谐的第一单频激光和可调谐的第二单频激光。调谐单元可以择一连接第一反射滤波单元40、第二反射滤波单元60、公共反射滤波单元30，也可以连接其中的两个滤波单元或者同时连接于三个滤波单元。
进一步地参考图2，采用第一调谐单元50对第一反射滤波单元40的中心波长λ1进行调节，而保持公共反射滤波单元30的中心波长λ0不变时，获得的第一单频激光的中心波长由λ101频移至λ102。参见图3，采用第一调谐单元50对第一反射滤波单元40的滤波带宽L1进行调节，采用第三调谐单元33对公共反射滤波单元30的滤波带宽L0进行调节，第一单频激光的带宽由L101变化为L102。在其他实施例中，在保持公共反射滤波单元30不变时调节第一调谐单元50也可以获得可调谐的第一单频激光。当然，公共反射滤波单元30的中心波长λ0和滤波带宽L0同时调节，可以使第一单频激光的中心波长和带宽的调节更加灵活以及可调范围更大。同理，通过第二调谐单元70对第二反射滤波单元60的中心波长和带宽进行调节，或者进一步同时调节公共反射滤波单元30，可以使第二单频激光的中心波长和带宽得到调节。
进而，本申请实施例提供的双频光源进一步具有如下效果：
通过公共反射滤波单元30和第一反射滤波单元40，基于偏差滤波实现极窄线宽单频激光输出，通过第一调谐单元50对第一反射滤波单元40进行调节，获得可调谐的第一单频激光，通过公共反射滤波单元30和第二反射滤波单元60，基于偏差滤波实现极窄线宽单频激光输出，通过第二调谐单元70对第二反射滤波单元60进行调节，获得可调谐的第二单频激光，进而在偏差滤波获得极窄线宽激光的基础上实现了双频输出，并且输出激光稳定而且调谐简易；并且，该双频光源理论上的频差为整个公共反射滤波单元30的光谱，能达到几十个MHz以上，调谐范围大，具有更强的作为探测光源的潜力。
本申请实施例为获得第一单频激光和第二单频激光所采用的偏差滤波方式还有如下效果：与传统的采用窄带光纤光栅和宽带光纤光栅作为腔镜的单频光源相比，一方面，不需设置制作难度极高的极窄带光纤光栅，对公共反射滤波单元30、第一反射滤波单元40和第二反射滤波单元60的带宽要求均不高，不被单个窄带滤波光栅的极窄滤波范围要求所限，可以用参数较低的光栅组成，极大的降低了工艺难度。
另一方面，传统单频光源为获得单频激光，还要满足窄带光栅的反射带宽小于纵模间隔，腔长越短纵模间隔越大，对窄带光栅的要求越低，然而腔长较短又会损失输出功率，进而传统单频光源存在窄带光栅性能和输出功率的相互制约，而本实施例不完全依赖于任一端滤波单元的滤波性能，即不需要使任一滤波带宽小于纵模间隔，进而解除对腔长的限制，避免各反射滤波单元的滤波性能和输出功率相互制约，使各反射滤波单元的选择以及谐振腔的设计更加灵活。
基于上述设计，以下通过实施例一至三提供几种直腔结构的双频光源。
实施例一：
参考图4，该直腔结构的双频光源中，包括上述的泵浦单元10、增益介质20、公共反射滤波单元30、第一反射滤波单元40、第一调谐单元50、第二反射滤波单元60、第二调谐单元70。其中，公共反射滤波单元30、第一反射滤波单元40和第二反射滤波单元60依次直线排布，增益介质20设置于公共反射滤波单元30和第一反射滤波单元40之间；公共反射滤波单元30和第一反射滤波单元40构成第一谐振腔的两端，公共反射滤波单元30和第二反射滤波单元60构成第二谐振腔的两端，第一谐振腔和第二谐振腔具有公共段，即公共反射滤波单元30和第一反射滤波单元40之间的部分。为了实现第二谐振腔内的激光传输，第一反射滤波单元40包括第一反射滤波波段区域41和第一透射波段区域42，激光的一部分能量由第一反射滤波波段区域41进行全反射或高反射以及滤波，用于形成可调谐的第一单频激光，激光的另一部分能量由第一透射波段区域42透射至第二反射滤波单元60，通过第二反射滤波单元60进行全反射后再次由第一透射波段区域42透射至公共反射滤波单元30，用于形成可调谐的第二单频激光。
如图5，作为另一种双频光源结构，可以设置第三调谐单元33，连接于公共反射滤波单元30，可以同时获得可调谐的第一单频激光和可调谐的第二单频激光。
在该实施例一中，公共反射滤波单元30采用部分反射滤波单元，用于对腔内激光进行部分反射和滤波以及输出第一单频激光和第二单频激光。并且，在泵浦单元10和公共反射滤波单元30之间设有第一泵浦光耦合单元81，用于将泵浦光从公共反射滤波单元30耦合进入第一谐振腔和第二谐振腔；公共反射滤波单元30输出第一单频激光和第二单频激光，再经由第一泵浦光耦合单元81输出。
可以理解，当不需要调谐时，本实施例也可以不使用第一调谐单元50、第二调谐单元70和第三调谐单元33，仅输出固定频率的双频激光。
进一步地，还可以在第一泵浦光耦合单元81输出第一单频激光和第二单频激光的方向上设置隔离单元90。还可以在泵浦单元10和第一泵浦光耦合单元81之间也可以设置另外一个隔离单元，避免反射回泵浦源，使泵浦源烧掉。
在本申请实施例中，泵浦单元10和第一泵浦光耦合单元81之间，第一泵浦光耦合单元81与公共反射滤波单元30之间，第一泵浦光耦合单元81和隔离单元90之间，均可通过光纤连接，实现全光纤双频光源。
或者，泵浦单元10和第一泵浦光耦合单元81之间可以通过光纤连接，第一泵浦光耦合单元81和隔离单元90之间可以通过光纤连接，第一泵浦光耦合单元81和公共反射滤波单元30之间可以通过自由空间进行光传输，实现部分光纤的双频光源。
或者，泵浦单元10和第一泵浦光耦合单元81之间可以通过自由空间进行光传输，第一泵浦光耦合单元81和公共反射滤波单元30之间可以通过光纤进行传输，第一泵浦光耦合单元81和隔离单元90之间可以通过光纤连接，也可以实现部分光纤的双频光源。
还可以采用其他自由空间和光纤混合连接的方式，或者采用全自由空间的连接方式。
实施例二：
参考图6，该实施例二提供的直腔结构中，公共反射滤波单元30仍然采用部分反射滤波单元，用于对腔内激光进行部分反射和滤波以及输出第一单频激光和第二单频激光。与实施例一不同的是，在第一谐振腔或第二谐振腔中设有第二泵浦光耦合单元82，用于将泵浦光耦合进入第一谐振腔和第二谐振腔。此时泵浦光经过谐振腔侧面进入，可调谐的第一单频激光和第二单频激光经公共反射滤波单元30输出。
同实施例一，各器件之间可以采用全光纤连接，或者采用自由空间连接和光纤连接组合的形式，或采用全空间连接形式等。
实施例三：
参考图7，该实施例三提供的直腔结构中，与实施例一不同的是，公共反射滤波单元30采用全反射滤波单元，用于对激光进行全反射和滤波；在第一谐振腔或第二谐振腔中设置第三泵浦光耦合单元83，用于将泵浦光经第一谐振腔或第二谐振腔的侧端输入；在第一谐振腔和第二谐振腔的公共部分设置输出单元100，用于将第一单频激光和第二单频激光输出。
同实施例一，各器件之间可以采用全光纤连接，或者采用自由空间连接和光纤连接组合的形式，或采用全空间连接形式等。
以下通过实施例四至八提供环腔结构的双频光源。
实施例四：
参考图8，该环腔结构的双频光源中，第一谐振腔和第二谐振腔为环腔结构，该双频光源除包括上述泵浦单元10、增益介质20、公共反射滤波单元30、第一反射滤波单元40、第一调谐单元50、第二反射滤波单元60、第二调谐单元70之外，还包括第四泵浦光耦合单元84、第一耦合器110和第二耦合器120；第四泵浦光耦合单元84具有三端口，第一端连接泵浦单元10，第二端直接或间接连接第一耦合器110，第三端直接或间接连接公共反射滤波单元30；第一反射滤波单元40和第二反射滤波单元60并联连接于第一耦合器110和第二耦合器120之间，即第一反射滤波单元40的一端和第二反射滤波单元60的一端共同直接或间接连接第一耦合器110，第一反射滤波单元40的另一端和第二反射滤波单元60的另一端共同直接或间接连接第二耦合器120；公共反射滤波单元30连接于第二耦合器120和第四泵浦光耦合单元84的第三端之间，进而形成环腔。
在该实施例中，“直接”是指二者之间不设置除导光线缆以外的其他元件，“间接”是指二者之间还设有除导光线缆以外的其他元件。
例如，第四泵浦光耦合单元84的第三端和公共反射滤波单元30之间还设有输出单元100。进一步地，还可以在输出单元100的输出方向设置隔离单元90。
第四泵浦光耦合单元84的第二端和第一耦合器110之间还设有增益介质20。另外，增益介质20还可以设置在第一谐振腔和第二谐振腔的公共段中的其他位置。
第一反射滤波单元40的一端和第二反射滤波单元60的一端和第一耦合器110之间还可以设置其他元件，第一反射滤波单元40的另一端和第二反射滤波单元60的另一端和第二耦合器120之间也可以设置其他元件，如实施例八。
同实施例一，各器件之间可以采用全光纤连接，或者采用自由空间连接和光纤连接组合的形式，或采用全空间连接形式等。当采用自由空间连接时，可以通过反射镜实现光路的折转，以构成环腔结构。
在本实施例中，可以在第一耦合器110和第二耦合器120之间的两条并联支路上分别设有一隔离器，两个隔离器的方向相同或相反，即，两个隔离器的允许顺时针方向传输，阻止逆时针方向传输；或者允许逆时针方向传输，阻止顺时针方向传输；或者其中一个隔离器允许顺时针方向传输，另一个隔离器允许逆时针方向传输。
在本实施例中，也可以在第四泵浦光耦合单元84和第一耦合器110之间的公共段上设有一隔离器；或者，在第四泵浦光耦合单元84和第二耦合器120之间的公共段上设有一隔离器，以防止激光反向传输。
实施例五：
参考图9，该实施例五与实施例四具有相同的主体结构（如泵浦单元10、增益介质20、公共反射滤波单元30、第一反射滤波单元40、第一调谐单元50、第二反射滤波单元60、第二调谐单元70、第四泵浦光耦合单元84、第一耦合器110和第二耦合器120及其连接结构），不同的是，输出单元100设置于第二耦合器120和公共反射滤波单元30之间。进一步地，还可以在输出单元100的输出方向设置隔离单元90。
实施例六：
参考图10，该实施例六与实施例四具有相同的主体结构（如泵浦单元10、增益介质20、公共反射滤波单元30、第一反射滤波单元40、第一调谐单元50、第二反射滤波单元60、第二调谐单元70、第四泵浦光耦合单元84、第一耦合器110和第二耦合器120及其连接结构），不同的是，在第一耦合器110和第二耦合器120之间的两条并联支路上分别设置一个输出单元100，即靠近第一反射滤波单元40设置一个输出单元100，用于输出可调谐第一单频激光，靠近第二反射滤波单元60设置另一输出单元100，用于输出可调谐第二单频激光。进一步地，可以在每个输出单元100的输出路径设置一个隔离单元90。
同实施例四，各器件之间可以采用全光纤连接，或者采用自由空间连接和光纤连接组合的形式，或采用全空间连接形式等。当采用自由空间连接时，可以通过反射镜实现光路的折转，以构成环腔结构。
实施例七：
参考图11，该实施例七与实施例四具有相同的主体结构（如泵浦单元10、增益介质20、公共反射滤波单元30、第一反射滤波单元40、第一调谐单元50、第二反射滤波单元60、第二调谐单元70、第四泵浦光耦合单元84、第一耦合器110和第二耦合器120及其连接结构），不同的是，公共反射滤波单元30采用部分反射滤波单元，其同时具有输出第一单频激光和第二单频激光的功能以及反射滤波功能。
实施例八：
参考图8，该环腔结构的双频光源具有实施例四所述的基本机构，例如泵浦单元10、增益介质20、公共反射滤波单元30、第一反射滤波单元40、第一调谐单元50、第二反射滤波单元60、第二调谐单元70、第四泵浦光耦合单元84、第一耦合器110和第二耦合器120及其连接结构等，不同的是，还包括第一环形器131、第二环形器132和第三环形器133，以便于形成公共反射滤波单元30、第一反射滤波单元40、第二反射滤波单元60的反射光路；第一环形器131的第一端连接第一耦合器110，第一环形器131的第二端连接第一反射滤波单元40，第一环形器131的第三端连接第二耦合器120；第二环形器132的第一端连接第一耦合器110，第二环形器132的第二端连接第二反射滤波单元60，第二环形器132的第三端连接第二耦合器120；第三环形器133的第一端连接第二耦合器120，第三环形器133的第二端连接公共反射滤波单元30，第三环形器133的第三端连接第四泵浦光耦合单元84。
在上述各实施例中，对于直腔或者环腔结构的双频光源，公共反射滤波单元30、第一反射滤波单元40、第二反射滤波单元60均可以采用两种结构，其一，采用能够对激光进行频率滤波和光强反射的一体结构，参见图12；其二，采用两个独立模块的组合结构，参见图13，第一反射滤波单元40包括第一反射镜43，以及设置于第一反射镜43的反射方向的第一滤波模块44；第二反射滤波单元60包括第二反射镜61以及设置于第二反射镜61的反射方向的第二滤波模块62；公共反射滤波单元30包括公共反射镜31以及设置于公共反射镜31的反射方向的公共滤波模块32。
可以理解，上述公共反射滤波单元30、第一反射滤波单元40、第二反射滤波单元60可以同时采用一体结构，也可以同时采用组合结构，也可以部分采用一体结构，部分采用组合结构。
在本申请的若干实施例中，增益介质20可以为增益光纤，或者为块状的增益晶体。
作为本申请实施例的优选方案，布拉格光纤光栅可在光纤上直接写入而形成光栅腔镜，因此与掺杂有源光纤的兼容性非常好，不仅连接损耗非常小，而且避免了复杂的光学结构，便于光纤激光器的集成和小型化，使光纤激光器具有更好的稳定性和可靠性，尤其适合环境条件非常恶劣的工作场所。因此在本实施例中，优选采用在光纤上直接写入布拉格光纤光栅而形成的一体结构的光栅腔镜作为公共反射滤波单元30、第一反射滤波单元40和第二反射滤波单元60，结构紧凑，且对于直腔而言，整个谐振腔长度较短，光源体积小；对于环腔而言，也能够适当减小体积。
以上仅为本发明的优选实施例而已，并不用于限制本发明。对于本领域的技术人员来说，本发明可以有各种更改和变化。凡在本发明的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本发明的权利要求范围之内。

Claims (15)

  1. 一种双频光源，其特征在于，包括
    泵浦单元，用于输出泵浦光；
    第一谐振腔，用于产生可调谐的第一单频激光；
    第二谐振腔，用于产生可调谐的第二单频激光；
    所述第一谐振腔包括：
    增益介质，用于经泵浦光激发产生激发光；
    公共反射滤波单元和第一反射滤波单元，用于对所述激发光进行反射和滤波，所述公共反射滤波单元和所述第一反射滤波单元的滤波范围部分重叠，以实现窄带滤波，用于获得第一单频激光；
    所述第二谐振腔包括：
    所述增益介质，用于经泵浦光激发产生激发光；
    所述公共反射滤波单元和第二反射滤波单元，用于对所述激发光进行反射和滤波，所述公共反射滤波单元和所述第二反射滤波单元的滤波范围部分重叠，以实现窄带滤波，用于获得第二单频激光。
  2. 如权利要求1所述的双频光源，其特征在于，所述第一谐振腔和第二谐振腔为直腔结构，所述公共反射滤波单元、所述第一反射滤波单元和第二反射滤波单元依次直线排布，所述增益介质设置于所述公共反射滤波单元和所述第一反射滤波单元之间；
    所述第一反射滤波单元包括第一反射滤波波段区域和第一透射波段区域；
    所述激光的一部分能量由所述第一反射滤波波段区域进行反射以及滤波，所述激光的另一部分能量由所述第一透射波段区域透射至所述第二反射滤波单元，通过所述第二反射滤波单元进行反射后再次由所述第一透射波段区域透射至所述公共反射滤波单元。
  3. 如权利要求2所述的双频光源，其特征在于，所述公共反射滤波单元采用部分反射滤波单元，用于对所述激光进行部分反射和滤波以及输出所述第一单频激光和第二单频激光。
  4. 如权利要求3所述的双频光源，其特征在于，所述泵浦单元和所述公共反射滤波单元之间设有第一泵浦光耦合单元，用于将所述泵浦光耦合进入所述第一谐振腔和第二谐振腔；所述公共反射滤波单元输出的第一单频激光和第二单频激光经由所述第一泵浦光耦合单元输出。
  5. 如权利要求3所述的双频光源，其特征在于，所述第一谐振腔或第二谐振腔中设有第二泵浦光耦合单元，用于将所述泵浦光耦合进入所述第一谐振腔和第二谐振腔。
  6. 如权利要求2所述的双频光源，其特征在于，所述双频光源还包括第三泵浦光耦合单元，设置于所述第一谐振腔或第二谐振腔中，用于将所述泵浦光经所述第一谐振腔或第二谐振腔的侧端输入；
    所述双频光源还包括输出单元，设置于所述第一谐振腔和第二谐振腔的公共部分，用于将所述第一单频激光和第二单频激光输出。
  7. 如权利要求1所述的双频光源，其特征在于，所述第一谐振腔和第二谐振腔为环腔结构，所述双频光源还包括第四泵浦光耦合单元、第一耦合器和第二耦合器；
    所述第四泵浦光耦合单元的第一端连接所述泵浦单元，所述第四泵浦光耦合单元的第二端连接所述第一耦合器，所述第四泵浦光耦合单元的第三端连接所述公共反射滤波单元；
    所述第一反射滤波单元和第二反射滤波单元并联连接于所述第一耦合器和第二耦合器之间，所述公共反射滤波单元连接于所述第二耦合器和所述第四泵浦光耦合单元的第三端之间。
  8. 如权利要求7所述的双频光源，其特征在于，所述双频光源包括一个输出单元，设置于所述第二耦合器和所述公共反射滤波单元之间；
    或者，所述双频光源包括两个输出单元，分别设置于所述第一耦合器和第二耦合器之间的两条并联支路上；
    在所述第一耦合器和第二耦合器之间的两条并联支路上分别设有一隔离器，两个隔离器的方向相同或相反；
    或者，在所述第四泵浦光耦合单元和第一耦合器之间的公共段上设有一隔离器；
    或者，在所述第四泵浦光耦合单元和第二耦合器之间的公共段上设有一隔离器。
  9. 如权利要求7所述的双频光源，其特征在于，所述双频光源还包括第一环形器、第二环形器和第三环形器；
    所述第一环形器的第一端连接所述第一耦合器，所述第一环形器的第二端连接所述第一反射滤波单元，所述第一环形器的第三端连接所述第二耦合器；
    所述第二环形器的第一端连接所述第一耦合器，所述第二环形器的第二端连接所述第二反射滤波单元，所述第二环形器的第三端连接所述第二耦合器；
    所述第三环形器的第一端连接所述第二耦合器，所述第三环形器的第二端连接所述公共反射滤波单元，所述第三环形器的第三端连接所述泵浦光耦合单元。
  10. 如权利要求1所述的双频光源，其特征在于，所述双频光源还包括设置于所述第一单频激光和第二单频激光的输出路径上的隔离单元。
  11. 如权利要求1所述的双频光源，其特征在于，所述双频光源还包括调谐单元，所述调谐单元连接于所述第一反射滤波单元，用于调节所述第一反射滤波单元的中心波长和/或带宽，以获得可调谐的第一单频激光；和/或
    所述调谐单元连接于所述第二反射滤波单元，用于调节所述第二反射滤波单元的中心波长和/或带宽，以获得可调谐的第二单频激光；和/或
    所述调谐单元连接于公共反射滤波单元，用于同时获得可调谐的第一单频激光和可调谐的第二单频激光。
  12. 如权利要求1至11任一项所述的双频光源，其特征在于，所述公共反射滤波单元为能够对所述激光进行滤波和反射的一体结构。
  13. 如权利要求1至11任一项所述的双频光源，其特征在于，所述公共反射滤波单元包括公共反射镜，以及设置于所述公共反射镜的反射方向的公共滤波模块。
  14. 如权利要求1至11任一项所述的双频光源，其特征在于，所述第一反射滤波单元为能够对所述激光进行滤波和反射的一体结构；所述第二反射滤波单元为能够对所述激光进行滤波和反射的一体结构。
  15. 如权利要求1至11任一项所述的双频光源，其特征在于，所述第一反射滤波单元包括第一反射镜，以及设置于所述第一反射镜的反射方向的第一滤波模块；
    所述第二反射滤波单元包括第二反射镜，以及设置于所述第二反射镜的反射方向的第二滤波模块。
PCT/CN2019/076148 2019-01-31 2019-02-26 一种双频光源 Ceased WO2020155249A1 (zh)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
CN201910099908.5A CN111509546B (zh) 2019-01-31 2019-01-31 一种双频光源
CN201920179007.2 2019-01-31
CN201920179007.2U CN209448211U (zh) 2019-01-31 2019-01-31 一种双频光源
CN201910099908.5 2019-01-31

Publications (1)

Publication Number Publication Date
WO2020155249A1 true WO2020155249A1 (zh) 2020-08-06

Family

ID=71841502

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2019/076148 Ceased WO2020155249A1 (zh) 2019-01-31 2019-02-26 一种双频光源

Country Status (1)

Country Link
WO (1) WO2020155249A1 (zh)

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1986006884A1 (en) * 1985-05-13 1986-11-20 Allied Corporation Multi-resonator switching laser
US7848381B2 (en) * 2008-02-15 2010-12-07 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Multiple-wavelength tunable laser
CN101950919A (zh) * 2010-09-07 2011-01-19 长春理工大学 全固态串联泵浦激光器
CN102195229A (zh) * 2010-03-02 2011-09-21 中国科学院福建物质结构研究所 新型正交偏振双波长激光器
CN104634370A (zh) * 2015-02-10 2015-05-20 深圳大学 一种基于激光器的传感器
CN104634369A (zh) * 2015-02-10 2015-05-20 深圳大学 一种环形激光器传感器
CN206211258U (zh) * 2016-08-25 2017-05-31 深圳大学 一种双频光源装置
CN206236953U (zh) * 2016-08-25 2017-06-09 深圳大学 一种双频光源
WO2018035813A1 (zh) * 2016-08-25 2018-03-01 深圳大学 一种双频光源
WO2018035806A1 (zh) * 2016-08-25 2018-03-01 深圳大学 一种双频光源装置
CN109149331A (zh) * 2018-09-25 2019-01-04 西北大学 一种基于双高反光纤光栅的短直腔单频光纤激光器

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1986006884A1 (en) * 1985-05-13 1986-11-20 Allied Corporation Multi-resonator switching laser
US7848381B2 (en) * 2008-02-15 2010-12-07 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Multiple-wavelength tunable laser
CN102195229A (zh) * 2010-03-02 2011-09-21 中国科学院福建物质结构研究所 新型正交偏振双波长激光器
CN101950919A (zh) * 2010-09-07 2011-01-19 长春理工大学 全固态串联泵浦激光器
CN104634370A (zh) * 2015-02-10 2015-05-20 深圳大学 一种基于激光器的传感器
CN104634369A (zh) * 2015-02-10 2015-05-20 深圳大学 一种环形激光器传感器
CN206211258U (zh) * 2016-08-25 2017-05-31 深圳大学 一种双频光源装置
CN206236953U (zh) * 2016-08-25 2017-06-09 深圳大学 一种双频光源
WO2018035813A1 (zh) * 2016-08-25 2018-03-01 深圳大学 一种双频光源
WO2018035806A1 (zh) * 2016-08-25 2018-03-01 深圳大学 一种双频光源装置
CN109149331A (zh) * 2018-09-25 2019-01-04 西北大学 一种基于双高反光纤光栅的短直腔单频光纤激光器

Similar Documents

Publication Publication Date Title
CN101532838B (zh) 一种光路复用的三轴一体化谐振式光纤陀螺
CN102508231B (zh) 基于飞秒光频梳的法-珀干涉绝对距离测量方法及装置
CN106253040B (zh) 一种通过石墨烯反射镜切换波长的锁模光纤激光器系统
CN108344408B (zh) 基于可调谐光电振荡器的角速度测量装置
CN105141258B (zh) 一种微波变频方法及装置
CN114739376B (zh) 基于二氧化硅波导偏振分束器的空芯光子晶体光纤陀螺
CN101387519A (zh) 一种空芯光子晶体光纤陀螺
WO2015167092A1 (ko) 처프 광섬유 브래그 격자 쌍을 이용한 광대역 고속 반복률 주사 광섬유 펨토초 레이저 공진기
CN109357672A (zh) 一种基于环形器结构的双向光载微波谐振系统及其检测角速度的方法
JP5324332B2 (ja) 光周波数コム安定化光源
CN103712615A (zh) 光功率反馈的单路闭环谐振式光学陀螺
CN111509546B (zh) 一种双频光源
CN103644961B (zh) 声压测量传感器及多纵模光纤激光器声压测量系统
CN103427326A (zh) 光纤集成式饱和吸收谱装置
CN206211258U (zh) 一种双频光源装置
CN116937314A (zh) 一种基于热原子蒸汽室的全光纤化激光稳频装置
CN104655159B (zh) 一种正交偏振激光器的传感器
CN114142332A (zh) 用于激光稳频的光学系统及激光稳频装置
CN209448211U (zh) 一种双频光源
WO2020155249A1 (zh) 一种双频光源
CN108548561A (zh) 一种双波光纤激光自混合干涉测量方法
CN206236953U (zh) 一种双频光源
CN207908818U (zh) 一种基于光纤耦合器和光学滤波器的转台双光束传输装置
CN107887785B (zh) 一种光纤与波导谐振环复合的单频光纤激光器
WO2018035806A1 (zh) 一种双频光源装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 19913653

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 19913653

Country of ref document: EP

Kind code of ref document: A1

32PN Ep: public notification in the ep bulletin as address of the adressee cannot be established

Free format text: NOTING OF LOSS OF RIGHTS PURSUANT TO RULE 112(1) EPC (EPO FORM 1205A DATED 26/01/2022)

122 Ep: pct application non-entry in european phase

Ref document number: 19913653

Country of ref document: EP

Kind code of ref document: A1