WO2014036845A1 - Filtre optique accordable sans rapport avec un état de polarisation de lumière incidente - Google Patents

Filtre optique accordable sans rapport avec un état de polarisation de lumière incidente Download PDF

Info

Publication number
WO2014036845A1
WO2014036845A1 PCT/CN2013/076170 CN2013076170W WO2014036845A1 WO 2014036845 A1 WO2014036845 A1 WO 2014036845A1 CN 2013076170 W CN2013076170 W CN 2013076170W WO 2014036845 A1 WO2014036845 A1 WO 2014036845A1
Authority
WO
WIPO (PCT)
Prior art keywords
liquid crystal
tunable
optically transparent
filter
transparent material
Prior art date
Application number
PCT/CN2013/076170
Other languages
English (en)
Chinese (zh)
Inventor
高培良
Original Assignee
天津奇谱光电技术有限公司
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 天津奇谱光电技术有限公司 filed Critical 天津奇谱光电技术有限公司
Publication of WO2014036845A1 publication Critical patent/WO2014036845A1/fr

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/11—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on acousto-optical elements, e.g. using variable diffraction by sound or like mechanical waves
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/21—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  by interference
    • G02F1/216—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  by interference using liquid crystals, e.g. liquid crystal Fabry-Perot filters
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/21—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  by interference
    • G02F1/213—Fabry-Perot type
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F2203/00—Function characteristic
    • G02F2203/06—Polarisation independent

Definitions

  • the invention belongs to the field of optoelectronic technology, in particular to a tunable optical filter which is independent of the polarization state of incident light. Background technique
  • the traditional optical Fabry-Perot etalon is a filter element fabricated using the principle of multi-beam interference.
  • the multi-wavelength interference effect of the Fabry-Perot cavity formed by the high reflectivity of the multilayer dielectric film on the two light-passing surfaces enables multi-wavelength narrow-band filtering output over a wide spectral range, and has stable performance. It has wide optical aperture, high optical power destruction threshold, simple structure and low cost. Therefore, it is widely used in various types of lasers, optical measuring instruments and optical fiber communication devices.
  • the tuning function of the transmitted optical frequency can be achieved using a conventional optical Fabry-Perot etalon.
  • tuning can be done by changing the angle of incidence of the light, but the tuning range of this method is small; it is also possible to change the Fabry by mechanical means (such as stepper motors).
  • the cavity length of the Perot etalon is tuned. This method can achieve a large tuning range, but the tuning accuracy is low, and the precision of the mechanical components is high and the stability is not good.
  • the PZT piezoelectric ceramic (lead zirconate titanate) technology can improve the tuning accuracy and speed by changing the cavity length of the Fabry-Perot etalon, but it is not easy to miniaturize and the drive circuit is complicated. Changing the temperature of the etalon can also achieve a wider range of tuning, but the disadvantage of this method is that it is slow.
  • the filter output characteristic of a single Fabry-Perot etalon is a multimode output with an optical frequency interval of free spectral range. .
  • the Acousto-Optical Tunable Filter is a solid-state, electronically tunable bandpass spectral filter that uses anisotropic acousto-optic interactions.
  • the advancement of crystal growth technology and high-frequency piezoelectric transducer technology has greatly improved the acousto-optic originals, making the AOTF technology mature and entering the industrial application from the laboratory.
  • AOTF implementations typically employ anisotropic birefringent acousto-optic (AO) media with high-speed tuning capabilities, proven long-term stability, and low cost.
  • acousto-optic filter The principle of operation of an acousto-optic filter is based on a phenomenon called Bragg diffraction, in which the direction of the diffracted light depends on the wavelength of the acoustic wave.
  • AOTF provides continuous and fast adjustment capability, but to achieve a narrow filter spectrum bandwidth, it is generally required that the size of the acousto-optic crystal is relatively large.
  • - Perot etalon has the same narrowband filtering function. Therefore, it is difficult to achieve narrowband output with a tunable laser using only an acousto-optic filter.
  • the object of the present invention is to overcome the deficiencies of the prior art and provide a tunable optical filter with high stability, high tuning precision, high speed, wide tuning range, narrow band and single mode output independent of the polarization state of incident light. .
  • a tunable optical filter independent of the polarization state of incident light comprising a tunable Fabry-Perot filter, a tunable acousto-optic filter, a polarization combining device, and a system control circuit;
  • a tunable Fabry-Perot filter, the output beam of which is passed through a tunable acousto-optic filter, the two polarization states of which are perpendicular to each other and have a separation angle of a linearly polarized beam, and the two linearly polarized beams are synthesized by polarized light.
  • the device is synthesized into a single beam and output; the system control circuit is respectively connected with the tunable Fabry-Perot filter and the tunable acousto-optic filter to realize the tunable output control function of the laser.
  • the tunable Fabry-Perot filter includes a first liquid crystal cell, a second liquid crystal cell, and a tunable Fabry-Perot filter driving circuit, which are sequentially mounted in front and rear, and two liquid crystal cells are The first optically transparent material, the liquid crystal material and the second optically transparent material are sequentially mounted together, and the second optically transparent material of the first liquid crystal cell is mounted together with the first optically transparent material of the second liquid crystal cell.
  • the first optically transparent material of the first liquid crystal cell is provided with a high-reflectivity multilayer dielectric film to form a first mirror
  • the second optically transparent material of the second liquid crystal cell is provided with a high-reflectivity multilayer dielectric film to form a second a mirror
  • the optical axes of the liquid crystal materials in the two liquid crystal cells are perpendicular to each other and disposed in a Fabry-Perot cavity composed of the first mirror and the second mirror
  • the tunable Fabry-Perot The driving circuit of the filter is connected with two liquid crystal cells and realizes the tuning function of the filter by controlling the effective refractive index of the liquid crystal material.
  • the driving circuit and system control of the tunable Fabry-Perot filter Circuit is connected.
  • the high-reflectivity multilayer dielectric film on the first optically transparent material of the first liquid crystal cell is disposed outside the first optically transparent material, and the inner side of the first optically transparent material is sequentially disposed from the inside to the outside.
  • a film of a conductive material covering a portion other than the clear aperture and a channel approximately 1 mm wide connected to the edge of the second sheet of optically transparent material for providing an exit for the excess liquid crystal material, and
  • the inside of a piece of optically transparent material forms a cavity for providing a liquid crystal material, and the transparent electrode is connected to a drive circuit of a tunable Fabry-Perot filter.
  • the high-reflectivity multilayer dielectric film on the first optically transparent material of the first liquid crystal cell is disposed inside the first optically transparent material
  • the transparent electrode is disposed inside the high-reflectivity multilayer dielectric film.
  • An optical antireflection film is disposed on an outer side of the first optically transparent material; an outer side of the second optically transparent material of the first liquid crystal cell is an optically polished surface, and an inner side of the second optically transparent material is optically enhanced from the inside to the outside.
  • An outlet, and the inside of the first piece of optically transparent material A cavity is formed for arranging the liquid crystal material, and the transparent electrode is connected to a driving circuit of the tunable Fabry-Perot filter.
  • the high-reflectivity multilayer dielectric film on the second optically transparent material of the second liquid crystal cell is disposed outside the second optically transparent material, and the inner side of the second optically transparent material is sequentially disposed from the inside to the outside.
  • An optical antireflection film and a transparent electrode wherein an outer side of the first optically transparent material of the second liquid crystal cell is an optically polished surface, and an inner side of the first optically transparent material is provided with an optical antireflection film and a transparent electrode from the inside to the outside.
  • a film of a non-conductive material covering a portion other than the clear aperture and a channel connected to the edge of the sheet of optically transparent material about 1 mm wide for providing an outlet for the excess liquid crystal material, and
  • the inside of the second optically transparent material of the two liquid crystal cells constitutes a cavity for providing a liquid crystal material, and the transparent electrode is connected to a driving circuit of the tunable Fabry-Perot filter.
  • a high-reflectivity multilayer dielectric film on the second optically transparent material of the second liquid crystal cell is disposed inside the second optically transparent material, and a transparent electrode is disposed on the inner side of the high-reflectivity multilayer dielectric film.
  • An optical antireflection film is disposed on an outer side of the second optically transparent material, wherein an outer side of the first optically transparent material of the second liquid crystal cell is an optically polished surface, and an inner side of the first optically transparent material is optically disposed from the inside to the outside.
  • the second optically transparent material of the first liquid crystal cell and the first optically transparent material of the second liquid crystal cell are mounted by: bonding together using an optically transparent index matching glue, and making the first reflection The mirror and the second mirror remain parallel to form a Fabry-Perot cavity.
  • liquid crystal material is a nematic liquid crystal having a thickness of several micrometers to ten micrometers.
  • the drive circuit of the tunable Fabry-Perot filter is a square wave pulse circuit having a frequency from one kilohertz to several kilohertz, and the pulse voltage amplitude is adjustable from 0 volts to 5 volts.
  • the free spectral range of the tunable Fabry-Perot filter is greater than the half width of the filter bandwidth of the tunable acousto-optic filter.
  • the tunable acousto-optic filter is a narrow-band, non-coaxial birefringence type acousto-optic filter, and the first-order diffraction splits the incident light into two polarization states that are perpendicular to each other and form a certain angle of linear polarization. Light.
  • the tunable acousto-optic filter is driven by a driving circuit of the tunable acousto-optic filter, the driving circuit of the tunable acousto-optic filter is connected to the system control circuit; the driving circuit of the tunable acousto-optic filter It is a frequency and power adjustable RF signal generator with frequencies from a few megahertz to hundreds of megahertz.
  • the polarized light synthesizing device includes a full-mirror mirror and a polarized light combiner, and the full-reflecting mirror reflects one of the linearly polarized light of the linearly polarized light whose two polarization states are perpendicular to each other and is output by the tunable acousto-optic filter
  • the polarized light combiner enters at or near 45 degrees; the other linearly polarized light output by the tunable acousto-optic filter enters the polarized light combiner directly at an angle of incidence of zero or near zero.
  • the present invention places two nematic liquid crystal materials having mutually perpendicular optical axes in a cavity of a Fabry-Perot etalon and utilizes an electrically controlled birefringence effect of the liquid crystal and an optical phase modulation of the incident light.
  • the continuous, fast and precise tuning of the frequency of the light transmitted through the Fabry-Perot filter over a wide spectral range is achieved regardless of the polarization state of the incident light. Since the thickness of the liquid crystal material is very thin, a wideband tunable Fabry-Perot filter having a small size and a large free spectral range can be fabricated.
  • Multimode optical waves output by tunable Fabry-Perot filters are tunable for single-mode and narrow-band outputs through tunable acousto-optic filter filtering and polarization synthesizers with high tuning accuracy, fast speed and tuning range Wide features.
  • the invention has reasonable design, non-mechanical moving parts, stable and reliable performance, small size, easy installation and production, and can meet the requirements of small size and extreme working environment, and can be widely used in laser and optical testing. , in the fields of fiber optic communications, biological, medical devices and fiber optic sensor networks.
  • Figure 1 is a schematic view of a conventional Fabry-Perot etalon
  • FIG. 2 is a schematic structural view of a first liquid crystal cell
  • FIG. 3 is a schematic structural view of a second liquid crystal cell
  • FIG. 4 is a schematic structural view of a tunable Brie-Perot filter
  • Figure 5 is a graph showing the phase of light transmitted through the liquid crystal material as a function of an applied electric field
  • Figure 6 is a schematic diagram of the transmission spectrum of a conventional Fabry-Perot etalon
  • FIG. 7 is a schematic diagram of a transmission spectrum of a tunable Brill-Perot filter
  • Figure 8 is a schematic diagram of a tunable acousto-optic filter
  • Figure 9 is a schematic view of a polarized light combiner
  • Figure 10 is a schematic structural view of the present invention.
  • Figure 11 is a schematic diagram of the output spectrum of the tunable acousto-optic filter
  • Figure 12 is a schematic diagram of the synthesized output spectrum of a tunable Fabry-Perot filter and a tunable acousto-optic filter;
  • Figure 13 is a schematic diagram of the output spectrum of the present invention.
  • FIG. Fabb A schematic of a conventional Fabry-Perot light etalon 100 is shown in FIG. Fabb
  • the material of the lin-Perot etalon 100 is generally optical glass such as fused silica or BK7 in the near-infrared and visible-light bands, assuming that the material has a refractive index n, and both light-passing surfaces 2 and 4 are plated with a high-reflection film.
  • the reflectance is R
  • the thickness h
  • the Fabry-Perot optical etalon's transmission spectrum is characterized by a very narrow bandwidth for each transmission spectrum, a uniform frequency spacing of the transmission spectrum and a very wide optical frequency response bandwidth, typically covering more than
  • the optical spectrum band of 100 nm, the output light spectrum of the optical etalon 100 is shown in Fig. 6.
  • a liquid crystal material generally used as a photovoltaic device has a high electrical resistivity, it can be considered as an ideal dielectric material.
  • the liquid crystal has anisotropic dielectric properties and uniaxial symmetry due to the ordered orientation of the molecules and the stretched morphology. Like a uniaxial crystal, the direction of the optical axis coincides with the alignment of the molecules.
  • an electric dipole is formed. Under the action of the moment formed by the electric dipole, the orientation of the liquid crystal molecules is turned to the direction of the electric field, and the direction of the optical axis of the liquid crystal can be changed by changing the strength of the electric field.
  • an optical phase modulator, a tunable filter or other optoelectronic devices such as an optical switch and a light intensity modulator can be fabricated using this characteristic of the liquid crystal.
  • the thickness of the liquid crystal film layer generally used as a photovoltaic device is from several micrometers to ten micrometers.
  • the present invention is designed by utilizing the fact that liquid crystals change the refractive index of linearly polarized light under the action of an electric field.
  • the tunable optical filter relating to the polarization state of incident light involved in the present invention includes two liquid crystal cells whose optical axis directions are perpendicular to each other.
  • the first liquid crystal cell 200 includes two structures.
  • the first structure comprises a first optically transparent material 8, a liquid crystal material 14 and a second optically transparent material 22.
  • the outer surface of the first optically transparent material 8 is provided with a high-reflectivity multilayer dielectric film 6, the inner side from the inside to the outside.
  • the optical antireflection film 10 and the transparent electrode film layer 12 are respectively disposed.
  • the outer surface 24 of the second optically transparent material 22 is an optically polished surface, and the optical antireflection film 20, the transparent electrode film layer 18 and the non-conductive layer are disposed on the inner side from the inside to the outside.
  • the material film 16, the non-conductive material film 16 has a thickness of several micrometers to ten micrometers, covers other portions except the light-passing aperture, and a channel having a width of about 1 mm to the edge of the optically transparent material 22 for removing excess
  • the liquid crystal material, the non-conductive material film 16 and the first piece of optically transparent material 8 form a cavity for arranging the liquid crystal material 14.
  • the liquid crystal material 14 is a nematic liquid crystal having a thickness of about several micrometers. Road ten A few microns.
  • the second structure of the liquid crystal cell 200 is different from the first structure in that an optical anti-reflection film 6 is disposed on the outer surface of the first optically transparent material 8, and a high-reflectivity multilayer dielectric is disposed on the inner side from the inside to the outside.
  • the film 10 and the transparent electrode film layer 12 are otherwise disposed in the same manner as the first structure of the liquid crystal cell 200, and the purpose thereof is to change the thickness of the Fabry-Perot cavity.
  • the second liquid crystal cell 300 includes two structures.
  • the first structure includes a first piece of optically transparent material
  • the liquid crystal material 36, the second optically transparent material 42, the outer surface 26 of the second optically transparent material 42 is provided with a high-reflectivity multilayer dielectric film 44, and the inner side is provided with an optical anti-reflection film 40 from the inside to the outside, a transparent electrode film Layer 32, the outer surface 26 of the first piece of optically transparent material 28 is an optically polished surface, and the inner side is provided with an optical anti-reflection film 30, a transparent electrode film layer 32 and a non-conductive material film 34, and a thickness of the non-conductive material film 34.
  • the portions other than the liquid crystal chambers of the two materials constituting the liquid crystal chamber are bonded together by an epoxy resin or an ultraviolet gel, and the liquid crystal material 36 is a nematic liquid crystal having a thickness of about several micrometers.
  • the road is a dozen microns.
  • the second structure of the liquid crystal cell 300 is different from the first structure in that an optical anti-reflection film 44 is disposed on the outer surface of the second optically transparent material 42, and a high-reflectivity multilayer dielectric film 40 is disposed on the inner side from the inside to the outside.
  • the transparent electrode film layer 38, the other arrangement is the same as the first structure of the liquid crystal cell 300, the purpose of which is to change the thickness of the Fabry-Perot cavity.
  • FIG. 4 shows a schematic diagram of a polarization-independent tunable Brie-Perot filter.
  • the tunable Fabry-Perot filter 400 includes a first liquid crystal cell 200, a second liquid crystal cell 300, and a tunable Fabry-Perot filtered drive circuit 52.
  • the outer side of the second piece of optically transparent material of the liquid crystal cell 200 and the outer side of the first piece of optically transparent material of the liquid crystal cell 300 are bonded together by the optically transparent index matching glue 50 and the first optically transparent material and liquid crystal of the liquid crystal cell 200 are made.
  • the faces of the second optically transparent material of the cartridge 300 provided with the high reflectivity dielectric film remain parallel to form a harmonic Fabry-Perot cavity.
  • the driving circuit 52 is connected to the transparent electrodes of the liquid crystal cell 200 and the liquid crystal cell 300, and the driving signal generated by the driving circuit 52 forms a driving electric field between the two transparent electrode film layers; the Fabry-Perot is changed by the electric field.
  • the effective refractive index n of the liquid crystal in the cavity adjusts the optical frequency V and the free spectral range (FSR) of the transmitted light of the Fabry-Perot filter.
  • a typical driving electric field is a square wave signal having a voltage of several volts and a frequency of 1 kHz to several kilohertz.
  • the filter 400 Since the thickness of the liquid crystal is small (several micrometers to ten micrometers), tunable Fabry-Perot can be made in the intrinsic free spectral range (ie, the free spectral range of the tunable filter without an applied electric field) filter. Since the optical axes of the liquid crystals in the first liquid crystal cell 200 and the second liquid crystal cell 300 are perpendicular to each other, the filter 400 is independent of the polarization state of the incident light. In FIG. 4, the light beam 48 incident on the filter 400 is a collimated beam, assuming that the refractive index of the optically transparent material is n, on the first optically transparent material of the first liquid crystal cell 200 and on the second liquid crystal cell 300.
  • the optical path produced by the incident light is changed by the refraction under the action of an applied electric field.
  • the combination of two different structures of the first liquid crystal cell 200 and the second liquid crystal cell 300 can increase or decrease the length D of the Fabry-Perot cavity, thereby adjusting the filter 400 free spectral range FSR2.
  • Figure 5 is a graph showing the relationship between the phase change of a 1525 nm light wave with a wavelength of about 10 ⁇ m nematic liquid crystal driven by a 2 kHz square wave voltage. A maximum optical phase delay of about 2 ⁇ can be achieved.
  • the tunable Fabry-Perot filter 400 can obtain a tuning range of about 1.5 times the transmitted optical frequency of FSR2 for collimated light near zero incidence, and a band of free spectral range ⁇ and transmitted light. The change in broadband is much smaller.
  • a schematic diagram of the spectrum of the transmitted light 54 of the tunable Fabry-Perot filter is shown in FIG.
  • the tunable Fabry-Perot filter 400 can achieve a large range of transmission light peak frequency tuning under the action of an applied electric field without substantially changing the bandwidth and free spectral range of the transmitted light. This feature is important for many applications in tunable Fabry-Perot filter 400, such as lasers and spectrum instruments.
  • Figure 8 shows a schematic of a tunable acousto-optic filter.
  • the medium used in the acousto-optic filter 500 is anisotropic and birefringent.
  • One of the materials cerium oxide (Te02), is widely used in such applications due to its high optical uniformity, low light absorption and high optical power capability in shear mode.
  • Other substances such as lithium niobate (LiNb03), gallium phosphide (GaP) and lead molybdate (PbMo04) are also frequently used in various acousto-optic devices. There are many factors that influence the selection of specific substances.
  • the tunable acousto-optic filter 500 is a non-collinear and non-paraxial acousto-optic filter having birefringence characteristics.
  • An acousto-optic crystal 57 and a transducer 58 employing cerium oxide are directly driven by a drive circuit 60 of the tunable acousto-optic filter to generate an acoustic wave field 59 in the crystal 57 to form a diffraction grating.
  • a collimated beam 56 enters the crystal 57 and forms a Bragg angle with the acoustic field 59.
  • the first-order diffracted light After being diffracted by the tunable acousto-optic filter, the first-order diffracted light is split into two linearly polarized lights, S-light 62 and neon 64, and zero.
  • the order diffracted beam 66 The angle between the two linearly polarized lights 62 and 64 and the zero order diffracted beam is equal to the Bragg angle ⁇ .
  • the cutting of the acousto-optic crystal 57 causes the incident surface 55 and the exit surface 61 to be perpendicular or close to the incident light. Straight angle. In order to reduce the loss of light, both the incident surface 55 and the exit surface 61 are plated with an optical antireflection film.
  • the filtered spectrum of the tunable acousto-optic filter 500 is characterized by continuous tunability of the optical frequency over a wide frequency range, as shown in FIG.
  • the bandwidth of the filtered spectrum, ⁇ ⁇ , half width (FWHM) ⁇ ⁇ 1/2 , resolution and diffraction efficiency depends on the size of the acousto-optic crystal, the structure of the transducer, and the RF drive power. To achieve narrowband filtering spectra and high diffraction filtering efficiency, it is necessary to increase the size of the transducer and acousto-optic crystal.
  • Figure 9 shows a schematic of a polarized light combiner.
  • the polarization synthesizer 70 is composed of two birefringent crystal prisms whose optical axes are at an angle.
  • the linearly polarized light 68 enters at zero degrees and passes directly through the polarization combiner 70.
  • the linearly polarized light S light 72 enters the polarization combiner 70 perpendicular to the pupil 68 and is reflected by the polarization combiner 70 at a right angle and transmitted through the polarization combiner.
  • the dawn of 70 merges into a beam of light 74.
  • FIG. 10 is a schematic view showing the structure of the present invention, and the technical solution of the present invention will be described below with reference to Fig. 10.
  • a tunable optical filter independent of polarization of incident light includes a tunable Fabry-Perot filter 400, a tunable acousto-optic filter 500, a polarized light combining device 70, a full mirror 84, and a A drive control system including a drive circuit 52 of the tunable Fabry-Perot filter 400, a drive circuit 60 of the tunable acousto-optic filter 500, and a system control circuit 94.
  • a collimated beam 76 is incident into the tunable Fabry-Perot filter 400.
  • the spectrum of the transmitted light 78 is shown in Figure 7.
  • the tunable range of the peak frequency of the transmitted light is about 1.5 times the FSR2, which is tunable.
  • the free spectral range of the tunable Fabry-Perot filter 400 remains substantially unchanged.
  • the transmitted light 78 passes through the tunable acousto-optic filter 500, the two beams 80 and 82 whose polarization states are perpendicular to each other are separated, and when the tunable acousto-optic filter 500 has a transmission bandwidth ⁇ V less than 2 times, the tunable Fabry- The intrinsic free spectral range FSR2 of the Perot filter 400, both transmitted light 80 and 82, is a bundle of single mode beams. If the spectral degree ⁇ ⁇ of the transmitted light of the tunable Fabry-Perot filter 400 is considered (refer to FIG. 12), the monotonic output or the high transmitted light side touch suppression ratio is realized, and the acousto-optic filter 500 is tuned.
  • the transmission bandwidth ⁇ ⁇ also needs to be narrower.
  • the polarization combiner 70 is positioned such that the pupil beam 82 is directly transmissive, and the S-light 80 is reflected by the mirror 84 and perpendicular to the beam 82.
  • the angle enters the polarization combiner 70, which is reflected and combined with the beam 82 into a beam of light 88.
  • the present invention can achieve single mode, continuous, narrowband and fast tuning outputs over a wide spectral range, the spectral characteristics of which are spectral characteristics of a transmission mode of a tunable Fabry-Perot filter 400.
  • the definition of the spectral width ⁇ V of the transmitted light of the tunable Fabry-Perot filter 400 and the tunable acousto-optic filter 500 is based on the need for noise or side-to-side suppression ratio of the spectrum in practical applications. definite.

Landscapes

  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Liquid Crystal (AREA)
  • Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)

Abstract

La présente invention porte sur un filtre optique accordable sans rapport avec un état de polarisation de lumière incidente qui comprend un filtre Fabry-Perot accordable (400), un filtre acoustooptique accordable (500), un appareil de synthèse de lumière polarisée (70) et un circuit de commande de système (94). Une lumière incidente (76) traverse d'abord le filtre Fabry-Perot accordable (400) et un faisceau lumineux délivré en sortie par le filtre Fabry-Perot accordable (400) traverse le filtre acoustooptique accordable (500). Le filtre acoustooptique accordable (500) délivre en sortie deux faisceaux lumineux polarisés linéairement (80, 82) ayant des états de polarisation mutuellement perpendiculaires et ayant un certain angle inclus séparé et les deux faisceaux lumineux polarisés linéairement (80, 82) sont synthétisés en un unique faisceau lumineux (88) par l'appareil de synthèse de lumière polarisée (70) et puis le faisceau lumineux unique (88) est délivré en sortie. Le circuit de commande de système (94) est respectivement relié au filtre Fabry-Perot accordable (400) et au filtre acoustooptique accordable (500), de manière à mettre en œuvre une fonction de commande de sortie accordable sur un laser. Le filtre optique accordable présente des caractéristiques d'être stable et fiable en performance, petit en dimensions et aisé pour montage et production et similaire et peut être largement appliqué dans les domaines de lasers, d'essai optique, de communications par fibre optique, de la biologie, d'instruments médicaux, de réseaux de capteurs à fibre optique et similaires.
PCT/CN2013/076170 2012-09-05 2013-05-23 Filtre optique accordable sans rapport avec un état de polarisation de lumière incidente WO2014036845A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201210325300.8A CN102798991B (zh) 2012-09-05 2012-09-05 一种与入射光的偏振态无关的可调谐光滤波器
CN201210325300.8 2012-09-05

Publications (1)

Publication Number Publication Date
WO2014036845A1 true WO2014036845A1 (fr) 2014-03-13

Family

ID=47198136

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2013/076170 WO2014036845A1 (fr) 2012-09-05 2013-05-23 Filtre optique accordable sans rapport avec un état de polarisation de lumière incidente

Country Status (2)

Country Link
CN (1) CN102798991B (fr)
WO (1) WO2014036845A1 (fr)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102798991B (zh) * 2012-09-05 2015-01-21 天津奇谱光电技术有限公司 一种与入射光的偏振态无关的可调谐光滤波器
CN102799013A (zh) * 2012-09-05 2012-11-28 天津奇谱光电技术有限公司 一种偏振无关的可调谐法布里-珀罗滤波器
CN105092015A (zh) * 2015-05-18 2015-11-25 清华大学 一种非接触式光纤振动传感系统及方法
CN111221158A (zh) * 2020-02-10 2020-06-02 浙江大学 对入射光偏振态不敏感的电可调滤光器

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030179790A1 (en) * 2002-03-25 2003-09-25 Fujitsu Limited Wavelength-selectable laser capable of high-speed frequency control
US20040218253A1 (en) * 2003-05-03 2004-11-04 Acceeze Inc. Tuning a narrow band filter for telecommunication applications with an acoustic optical tunable filter
WO2005036241A1 (fr) * 2003-10-10 2005-04-21 Shoei Kataoka Filtre variable en longueur d'onde et procede de production de ce filtre
CN102798991A (zh) * 2012-09-05 2012-11-28 天津奇谱光电技术有限公司 一种与入射光的偏振态无关的可调谐光滤波器
CN102820611A (zh) * 2012-09-05 2012-12-12 天津奇谱光电技术有限公司 一种非偏振光输出的可调谐激光器
CN102829870A (zh) * 2012-09-05 2012-12-19 天津奇谱光电技术有限公司 一种光学频谱分析设备

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3914055A (en) * 1974-05-23 1975-10-21 Lansing Research Corp Instrument for high resolution spectral analysis with large optical throughput
CA2060576C (fr) * 1991-02-04 1995-09-26 Katsuhiko Hirabayashi Filtre de selection de longueur d'onde accordable electriquement
US6545739B1 (en) * 1997-09-19 2003-04-08 Nippon Telegraph And Telephone Corporation Tunable wavelength filter using nano-sized droplets of liquid crystal dispersed in a polymer
CN101626141B (zh) * 2009-08-06 2011-05-04 浙江大学 基于组合型调谐滤波器的全光纤快速扫频激光光源

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030179790A1 (en) * 2002-03-25 2003-09-25 Fujitsu Limited Wavelength-selectable laser capable of high-speed frequency control
US20040218253A1 (en) * 2003-05-03 2004-11-04 Acceeze Inc. Tuning a narrow band filter for telecommunication applications with an acoustic optical tunable filter
WO2005036241A1 (fr) * 2003-10-10 2005-04-21 Shoei Kataoka Filtre variable en longueur d'onde et procede de production de ce filtre
CN102798991A (zh) * 2012-09-05 2012-11-28 天津奇谱光电技术有限公司 一种与入射光的偏振态无关的可调谐光滤波器
CN102820611A (zh) * 2012-09-05 2012-12-12 天津奇谱光电技术有限公司 一种非偏振光输出的可调谐激光器
CN102829870A (zh) * 2012-09-05 2012-12-19 天津奇谱光电技术有限公司 一种光学频谱分析设备

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
CHANG, I.C. ET AL.: "Acousto-optic tunable filters for high resolution spectral analysis", PROCEEDINGS OF THE SPIE, IMAGING SPECTROSCOPY I, vol. 0268, 21 July 1981 (1981-07-21), pages 167 - 170 *

Also Published As

Publication number Publication date
CN102798991B (zh) 2015-01-21
CN102798991A (zh) 2012-11-28

Similar Documents

Publication Publication Date Title
US10418775B2 (en) External cavity tunable laser with dual beam outputs
CN102709799B (zh) 一种宽带连续可调谐激光器
WO2014036842A1 (fr) Laser accordable pour délivrer une lumière non polarisée
WO2015101049A1 (fr) Système laser ajustable
WO2014036844A1 (fr) Filtre fabry-perot accordable sans rapport avec une polarisation
WO2014036843A1 (fr) Dispositif d'analyse de spectre
WO2011120246A1 (fr) Laser réglable
WO2011134177A1 (fr) Laser accordable
CN102306900B (zh) 偏振耦合的双增益介质的外腔式宽带可调谐激光器
CN102299472B (zh) 光频率精密可调谐激光器
CN101672988A (zh) 声光可调谐滤波器
WO2014036845A1 (fr) Filtre optique accordable sans rapport avec un état de polarisation de lumière incidente
WO2012167447A1 (fr) Laser accordable à cavité extérieure doté d'un intervalle de fréquence de 25 ghz
CN103779777A (zh) 一种使用可调谐法布里-珀罗滤波器的可调谐激光器
CN102332678B (zh) 滤波器耦合双激光增益介质的外腔式宽带可调谐激光器
WO2012145551A2 (fr) Filtres optiques accordables à résonateurs à cristaux liquides
WO2013189108A1 (fr) Filtre fabry-pérot accordable
WO2014019398A1 (fr) Filtre optique monomode accordable en continu
WO2014019399A1 (fr) Filtre optique accordable à intervalles de fréquences fixes et sortie monomode
WO2003083519A2 (fr) Filtre acousto-optique accordable comportant une zone d'interaction acousto-optique
JP2004191904A (ja) 波長選択装置、波長選択レーザおよび波長可変レーザ
JP4639663B2 (ja) 波長可変ミラーおよび波長可変レーザ
Kaplan et al. A simple theory of the acousto-optic programmable dispersive filter used for femtosecond laser pulse shaping

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: 13835496

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: 13835496

Country of ref document: EP

Kind code of ref document: A1