CN110967790B - Optical fiber coupling method for PPLN waveguide device, waveguide device and single photon detector - Google Patents
Optical fiber coupling method for PPLN waveguide device, waveguide device and single photon detector Download PDFInfo
- Publication number
- CN110967790B CN110967790B CN201811153884.9A CN201811153884A CN110967790B CN 110967790 B CN110967790 B CN 110967790B CN 201811153884 A CN201811153884 A CN 201811153884A CN 110967790 B CN110967790 B CN 110967790B
- Authority
- CN
- China
- Prior art keywords
- optical fiber
- micro
- waveguide
- nano
- nano optical
- 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.)
- Active
Links
- 239000013307 optical fiber Substances 0.000 title claims abstract description 133
- 238000010168 coupling process Methods 0.000 title claims abstract description 65
- 230000008878 coupling Effects 0.000 claims abstract description 43
- 238000005859 coupling reaction Methods 0.000 claims abstract description 43
- 238000000034 method Methods 0.000 claims abstract description 24
- 239000002121 nanofiber Substances 0.000 claims abstract description 23
- 239000000835 fiber Substances 0.000 claims description 19
- 238000009826 distribution Methods 0.000 claims description 14
- GQYHUHYESMUTHG-UHFFFAOYSA-N lithium niobate Chemical compound [Li+].[O-][Nb](=O)=O GQYHUHYESMUTHG-UHFFFAOYSA-N 0.000 claims description 13
- 239000000853 adhesive Substances 0.000 claims description 12
- 230000001070 adhesive effect Effects 0.000 claims description 12
- 238000013178 mathematical model Methods 0.000 claims description 11
- 238000006243 chemical reaction Methods 0.000 claims description 8
- 238000000227 grinding Methods 0.000 claims description 3
- 238000005498 polishing Methods 0.000 claims description 3
- 238000004088 simulation Methods 0.000 abstract description 7
- 238000004519 manufacturing process Methods 0.000 abstract description 3
- 238000013461 design Methods 0.000 abstract description 2
- 239000003292 glue Substances 0.000 description 7
- 230000003287 optical effect Effects 0.000 description 6
- 238000005253 cladding Methods 0.000 description 5
- 230000008901 benefit Effects 0.000 description 4
- 238000004364 calculation method Methods 0.000 description 4
- 238000002360 preparation method Methods 0.000 description 4
- 238000004891 communication Methods 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 230000010287 polarization Effects 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 238000007792 addition Methods 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000012792 core layer Substances 0.000 description 1
- 230000001808 coupling effect Effects 0.000 description 1
- 238000012938 design process Methods 0.000 description 1
- 229910003460 diamond Inorganic materials 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000005669 field effect Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- GPRLSGONYQIRFK-UHFFFAOYSA-N hydron Chemical compound [H+] GPRLSGONYQIRFK-UHFFFAOYSA-N 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000013519 translation Methods 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/26—Optical coupling means
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J11/00—Measuring the characteristics of individual optical pulses or of optical pulse trains
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
- G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
- G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
- G02B2006/12035—Materials
- G02B2006/1204—Lithium niobate (LiNbO3)
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
- G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
- G02B2006/12133—Functions
- G02B2006/12147—Coupler
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)
- Optical Couplings Of Light Guides (AREA)
Abstract
The invention provides a micro-nano fiber-based high-efficiency optical fiber coupling method for a PPLN waveguide device, wherein the optimal matching of a micro-nano fiber mode field and a PPLN waveguide mode field is realized to the maximum extent by changing the diameter of an optical fiber, so that the purpose of high-efficiency coupling of the micro-nano fiber and the PPLN waveguide is achieved, and the optimal matching result can be obtained in advance in a numerical simulation mode, so that the matching method can be implemented with high efficiency and low cost, and the design and manufacturing cost of the PPLN waveguide device is greatly reduced.
Description
Technical Field
The invention relates to the field of optical devices, in particular to a high-efficiency optical fiber coupling method for a Periodically Poled Lithium Niobate (PPLN) waveguide device, the waveguide device prepared by the method and a single photon detector comprising the waveguide device.
Background
The Periodic Polarization Lithium Niobate (PPLN) waveguide is one of core key devices of quantum communication, frequency conversion from photons in a communication waveband to a visible light waveband is realized by the PPLN waveguide, and then a commercial silicon detector is used for detection, so that the problem of low detection efficiency of single photons in the communication waveband can be solved. The reverse proton exchange-based PPLN waveguide has the advantages of low transmission and coupling loss, high conversion efficiency and the like due to moderate refractive index change, controllable light spot mode and easy realization of the process advantage of a long chip, and the current reverse proton exchange-based PPLN waveguide has very high conversion efficiency and can achieve nearly 100% frequency conversion.
In the application of a PPLN waveguide, it is necessary to couple an optical fiber with the PPLN waveguide to form a PPLN waveguide device with input/output, and it is common to use a single-mode optical fiber or a polarization-maintaining optical fiber to directly couple with the PPLN waveguide, as shown in fig. 1.
However, the direct coupling of the fiber to the PPLN waveguide device introduces an insertion loss problem, which consists of three parts: alignment bias loss, fresnel reflection (multiple reflections from both end faces) loss, and mode field mismatch loss between the waveguide and the fiber. The alignment deviation loss caused by the dislocation of the end faces of the waveguide and the optical fiber can be eliminated by adopting a high-precision adjusting frame alignment mode; the fresnel reflection loss caused by the end reflection can be eliminated by using the antireflection film and the refractive index matching liquid. The coupling loss of the optical fiber and the PPLN waveguide is about 1dB under the condition of deducting the alignment deviation loss and the Fresnel reflection loss.
In the prior art, a single-mode (polarization-maintaining) fiber is generally directly aligned with the PPLN waveguide for coupling. For SMF-28e standard single mode fiber, the corresponding diameters of the core and cladding are 9um and 125um, respectively, and correspondingly for light with a wavelength of 1550nm, the corresponding refractive indices of the core and cladding are 1.468 and 1.4627, respectively. The present inventors have obtained the mode field distribution in such fibers by finish-Difference Time-domain (fdtd) simulation calculations. FIG. 2 shows the mode field distribution of 1550nm light in SMF-28e standard single-mode fiber, from which it can be calculated that its mode field diameter (i.e. the distance between two points where the light intensity drops to 1/e ^2 of the maximum light intensity) is 10.1 um.
Fig. 3 shows the structure of a PPLN waveguide of the type commonly found in the prior art. As shown, the incident end of the PPLN waveguide is designed with a mode filter to enable more efficient coupling of the fiber to the PPLN waveguide. The mode filter is usually realized by a hydrogen ion replacement method, so that the refractive index distribution of the mode filter can be obtained by an ion diffusion equation, and on the basis, the mode field distribution of the mode filter is calculated by FDTD simulation, as shown in FIG. 4.
Comparing the mode field distributions shown in fig. 2 and 4, it can be seen that the mode field matching between the standard single mode fiber and the PPLN waveguide is not perfect, and this direct alignment coupling will result in a loss of about 1dB, thereby significantly reducing the frequency conversion efficiency of the PPLN waveguide.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides an optical fiber coupling method for a PPLN waveguide device, which can realize high coupling efficiency, and also provides a waveguide device prepared by the method and a single photon detector comprising the waveguide device. Specifically, in the coupling method provided by the invention, the micro-nano optical fiber is used for coupling with the PPLN waveguide, wherein the fiber coupling efficiency of the PPLN waveguide is improved by optimizing the stretching diameter of the micro-nano optical fiber to improve the matching degree of the intrinsic mode field of the fiber and the waveguide.
In the optical fiber coupling method for the periodically poled lithium niobate waveguide device of the present invention, the waveguide device includes a micro-nano optical fiber and a periodically poled lithium niobate waveguide, wherein the method may include the following steps:
step one, establishing a model of the waveguide device, obtaining intrinsic mode field distribution in the waveguide device under a certain wavelength based on the model, and calculating the coupling efficiency between the micro-nano optical fiber and the waveguide;
changing the diameter of the micro-nano optical fiber, repeating the first step to obtain a relation curve of the coupling efficiency and the diameter of the micro-nano optical fiber, and determining the diameter range of the micro-nano optical fiber used for the waveguide device according to the relation curve;
step three, preparing the micro-nano optical fiber, wherein the diameter of the micro-nano optical fiber is within the diameter range; and
step four, directly coupling the micro-nano optical fiber prepared in the step three to the waveguide according to the model.
Preferably, in the third step, the diameter of the micro-nano optical fiber can be controlled within the diameter range by using a tapering method.
Preferably, the third step may further include a step of sleeving a micro-nano optical fiber with a micro-pipe.
Preferably, the third step may further include a step of applying an adhesive between the micro-nanofiber and the microtube.
Preferably, the diameter range of the micro-nano optical fiber can be 5.2-6.5 μm, so that efficient coupling between the micro-nano optical fiber and the periodically polarized lithium niobate waveguide is provided for signal light with the wavelength of 1550 nm.
Preferably, the third step may further include a step of grinding and polishing the emergent end face of the micro-nano optical fiber.
Preferably, the fourth step may include a step of precisely aligning the micro-nanofiber with the waveguide according to the model. And further, the fourth step can also comprise the step of solidifying the micro-nano optical fiber on the waveguide.
Preferably, an antireflection film may be disposed on the end face of the waveguide.
Preferably, the model is a mathematical model. Further, in the mathematical model, the refractive index of the surface medium of the micro-nano optical fiber can be set according to the refractive index of the adhesive.
More preferably, the refractive index of the surface medium of the micro-nano optical fiber may be set to 1.38 in the mathematical model.
The invention also discloses a periodically poled lithium niobate waveguide device, which comprises a periodically poled lithium niobate waveguide and a micro-nano optical fiber, wherein the micro-nano optical fiber can be directly coupled with the waveguide by the optical fiber coupling method.
In yet another aspect of the invention, an up-conversion single photon detector is disclosed comprising a periodically poled lithium niobate waveguide device according to the invention.
Drawings
FIG. 1 shows a prior art configuration in which a single mode (or polarization maintaining) fiber is directly coupled to a PPLN waveguide;
FIG. 2 shows the mode field distribution of 1550nm light in SMF-28e standard single-mode fiber;
FIG. 3 shows the structure of a PPLN waveguide of the type commonly found in the prior art;
FIG. 4 shows the mode field distribution of 1550nm light in the PPLN waveguide (input end) shown in FIG. 3; and
fig. 5 shows a curve of the coupling efficiency between the micro-nano fiber and the PPLN waveguide according to the present invention as a function of the diameter of the micro-nano fiber.
Detailed Description
Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following examples are provided by way of illustration in order to fully convey the spirit of the invention to those skilled in the art to which the invention pertains. Accordingly, the present invention is not limited to the embodiments disclosed herein.
Compared with a standard single-mode fiber, the micro-nano fiber has the diameter of the micro-nano fiber, and because air is used as a fiber cladding, a large refractive index difference is formed between a core layer and the cladding, the micro-nano fiber has strong constraint capacity on light; in addition, the micro-nano optical fiber also has the advantages of wide material source, high mechanical strength and the like. The micro-nano optical fiber has the characteristics of small size, small light transmission loss, flexibility and the like, so that the micro-nano optical fiber is often applied to manufacturing optical devices such as a resonant cavity, a laser, a sensor and the like with micro-nano sizes in the prior art, and is particularly widely applied to optical sensing elements based on evanescent field effect by means of the fact that the surface of the micro-nano optical fiber has a strong evanescent field when light is transmitted in the micro-nano optical fiber.
In the optical fiber coupling method for the PPLN waveguide device, the micro-nano optical fiber is used for realizing the high-efficiency coupling between the optical fiber and the PPLN waveguide, so that the problem of overlarge coupling loss in the waveguide device realized by using a standard single-mode optical fiber and the PPLN waveguide in the prior art is solved.
Specifically, the optical fiber coupling method according to the present invention may include the following steps.
The method comprises the following steps: establishing a model of the PPLN waveguide device (namely the PPLN waveguide and the micro-nano optical fiber coupled with the PPLN waveguide device), obtaining the intrinsic mode field distribution in the PPLN waveguide device, and calculating the coupling efficiency between the micro-nano optical fiber and the PPLN waveguide.
Step two: changing the diameter of the micro-nano optical fiber, repeating the first step to obtain a relation curve of the coupling efficiency and the diameter of the micro-nano optical fiber, and determining the diameter range of the micro-nano optical fiber coupled with the PPLN waveguide according to the relation curve.
Step three: and preparing the micro-nano optical fiber with the diameter range.
Step four: and coupling the micro-nano optical fiber to the PPLN waveguide according to the model and solidifying the micro-nano optical fiber.
According to the present invention, a mathematical model of the PPLN waveguide device is preferably established in step one, whereby the eigenmode field distribution of the PPLN waveguide can be obtained by means of numerical simulation calculations. As a preferred example, numerical simulation calculations may be performed by means of the FDTD method. Those skilled in the art will readily appreciate that the manner in which the eigenmode field distribution is obtained based on a model of the waveguide device is not so limited.
In addition, the inventor researches and discovers that since the micro-nano optical fiber is very fine (the diameter is in the micrometer range), and the surface is easily polluted by dust to influence the performance of the device, the inventor proposes that when the micro-nano optical fiber is directly coupled with a PPLN waveguide, a micro-pipe is preferably sleeved on the optical fiber to provide a cured package for the micro-nano optical fiber, and an adhesive can be preferably filled on the surface of the micro-nano optical fiber to realize fixed connection between the optical fiber and the micro-pipe. Therefore, in order to provide better simulation effect, the refractive index of the surface medium of the micro-nano optical fiber can be set to be consistent with that of the adhesive in a mathematical model related to a waveguide device.
According to the present invention, a silica microtube can be preferably used as the microtube.
For a better understanding of the principles of the present invention, a preferred embodiment of the fiber coupling method of the present invention will be described below in connection with a fiber coupling design process in a waveguide device for 1550nm optical signals.
As previously mentioned, in step one of the methods of the present invention, a model of the waveguide device is created.
In this preferred example, the model may be a mathematical model based on the FDTD method. The adhesive may preferably be glue with a refractive index of 1.38. Accordingly, the refractive index of the surface medium of the micro-nano optical fiber can be set to 1.38 in a mathematical model related to a waveguide device.
After establishing a model of the waveguide device, the intrinsic mode field distribution in the waveguide device at a certain signal light wavelength (for example 1550nm) can be obtained, and the coupling efficiency between the micro-nano optical fiber and the PPLN waveguide can be further obtained. Preferably, the above-mentioned intrinsic mode field distribution and coupling efficiency of the optical fiber and the waveguide can be calculated by an FDTD numerical calculation method based on an FDTD mathematical model.
And step two is used for obtaining a curve graph of the coupling efficiency changing along with the diameter of the optical fiber. Specifically, in the second step, the diameter of the micro-nano optical fiber is changed, and the first step is repeated, so that the coupling efficiency data between the micro-nano optical fiber and the PPLN waveguide under a plurality of optical fiber diameters is obtained, and the relation curve of the coupling efficiency with respect to the diameter of the micro-nano optical fiber is obtained.
Fig. 5 shows a variation curve of the coupling efficiency of the micro-nano optical fiber and the PPLN waveguide with respect to the diameter of the micro-nano optical fiber for an optical signal having a wavelength of 1550nm, and it can be seen therefrom that when the diameter of the micro-nano optical fiber is 5.2 to 6.5 μm, a good coupling can be achieved between the optical fiber and the waveguide, and the coupling efficiency thereof can be more than 96% (about 0.2 dB).
In a preferred example of the present invention, it was determined that the diameter of the micro-nano optical fiber for direct coupling with the PPLN waveguide ranges from 5.2 to 6.5 μm for signal light having a wavelength of 1550 nm.
The three steps are used for preparing the micro-nano optical fiber with the preferable diameter range (for example, 5.2-6.5 mu m). Those skilled in the art know that there are many methods for preparing micro-nano optical fibers in the prior art, and any method capable of realizing the micro-nano optical fiber within the preferred diameter range of the present invention can be applied to the third step.
As a preferable example, the micro-nano optical fiber can be prepared by adopting a tapering method. For example, the fiber diameter may be controlled to 5.2-6.5 μm by a tapering translation stage and the cleaving operation may be performed after the stretching is stopped by cutting the stretched fiber, such as with a diamond blade.
As described above, the inventors of the present invention have studied and found that since the micro-nano optical fiber has a dimension of a micrometer scale, it will have a very small contact area when directly coupled with the end surface of the PPLN waveguide, and therefore, it is preferable to jacket the micro-nano optical fiber with a micro-pipe, and it is also preferable to use an adhesive to bond the micro-nano optical fiber and the PPLN waveguide when the micro-pipe is jacketed. Therefore, the third step may further include a step of sleeving the micro-nano optical fiber with a micro-tube and a step of applying an adhesive between the optical fiber and the micro-tube. As a preferable example, a carbon dioxide microtube can be sleeved on the micro-nano optical fiber, and glue with a refractive index of 1.38 can be dripped on the edge of the micro-nano optical fiber. The glue penetrates into the inside of the microtube by capillary action, thereby filling the entire cannula.
After the glue is distributed in the sleeve, the glue in the micro-tube can be solidified through ultraviolet lamp irradiation, and at the moment, the glue with low refractive index positioned outside the optical fiber can also play a role of a micro-nano optical fiber cladding.
Further, the inventor also notes that, because the cutting operation of the micro-nano optical fiber is often difficult to ensure the leveling of the tapered end face of the optical fiber, and an ultraviolet curing adhesive may remain on the end face of the optical fiber in the operation step of applying the adhesive, the leveling of the end face of the optical fiber may be reduced, and the optical field mode at the coupling position of the optical fiber may be affected. Therefore, the third step of the invention can preferably include a step of grinding and polishing the emergent end face of the micro-nano optical fiber, so as to ensure that the prepared micro-nano optical fiber cone has a smooth end face.
And step four, directly coupling the micro-nano optical fiber to the PPLN waveguide.
For this purpose, a step of accurately aligning the micro-nano fiber with the PPLN waveguide according to a model is performed. As a preferred example, the micro-nano fiber may be placed on a high-precision adjusting frame, and the physical alignment between the micro-nano fiber and the PPLN waveguide may be achieved by finely adjusting the position of the micro-nano fiber, so as to be consistent with the model in step one.
Subsequently, a step of curing the micro-nano fiber on the PPLN waveguide may also be performed. As a preferred example, the fixed connection between the end face of the PPLN waveguide and the micro-nano fiber may be achieved by means of an adhesive. For example, an ultraviolet curing glue may be dropped on the contact end face of the PPLN waveguide and the micro-nano fiber, and the micro-nano fiber taper and the PPLN waveguide may be cured by irradiation of an ultraviolet curing lamp.
In the invention, the end face of the PPLN waveguide can be preferably plated with an antireflection film, so that Fresnel reflection between the micro-nano optical fiber and the end face of the PPLN waveguide is eliminated or reduced, and the coupling efficiency is increased.
Based on the foregoing description of the principle and preferred examples of the present invention, in the present invention, a method for efficiently coupling an optical fiber for a PPLN waveguide device based on a micro-nano fiber is proposed by using the characteristic that the mode field of the micro-nano fiber is directly related to the diameter of the optical fiber. In the method, the optimal matching of the mode field of the micro-nano optical fiber and the mode field of the PPLN waveguide is realized to the maximum extent by changing the diameter of the optical fiber, so that the aim of efficiently coupling the micro-nano optical fiber and the PPLN waveguide is fulfilled, and the optimal matching result can be obtained in advance in a numerical simulation mode, so that the matching method can be implemented efficiently at low cost, and the design and manufacturing cost of the PPLN waveguide device is greatly reduced. Secondly, according to the method for preparing the micro-nano optical fiber provided by the invention, the preparation of the micro-nano optical fiber can be realized in a very simple and effective mode, for example, the preparation can be realized by heating a standard single-mode optical fiber through hydrogen, so that the advantages of simple technology, high transmittance of the optical fiber, low cost and the like are provided, and the waveguide device is formed by directly coupling with the waveguide chip, so that the preparation cost of the PPLN waveguide device is very reduced.
In addition, the invention also provides a PPLN waveguide device with high coupling efficiency, which can comprise a PPLN waveguide and a micro-nano optical fiber directly coupled to the end face of the waveguide. Wherein, the diameter range of the micro-nano optical fiber can be between 5.2 and 6.5 mu m. Preferably, in order to obtain a better coupling effect, the preparation of the micro-nano optical fiber and the coupling with the waveguide can be performed according to the method described above.
Furthermore, the invention also provides an up-conversion single photon detector which comprises a PPLN waveguide device, wherein the PPLN waveguide device can be prepared by the optical fiber coupling method.
The above description is not intended to limit the present invention, and the present invention is not limited to the above examples. Those skilled in the art will also appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
Claims (13)
1. An optical fiber coupling method for a periodically poled lithium niobate waveguide device, wherein the waveguide device comprises a micro-nano optical fiber and a periodically poled lithium niobate waveguide, and the method is characterized by comprising the following steps:
step one, establishing a model of the waveguide device, obtaining intrinsic mode field distribution in the waveguide device under a certain wavelength based on the model, and calculating the coupling efficiency between the micro-nano optical fiber and the waveguide;
changing the diameter of the micro-nano optical fiber, repeating the first step to obtain a relation curve of the coupling efficiency and the diameter of the micro-nano optical fiber, and determining the diameter range of the micro-nano optical fiber used for the waveguide device according to the relation curve;
step three, preparing the micro-nano optical fiber, wherein the diameter of the micro-nano optical fiber is within the diameter range; and
and fourthly, directly coupling the micro-nano optical fiber prepared in the third step to the waveguide through an end face according to the model, wherein the method comprises the step of accurately aligning the micro-nano optical fiber with the waveguide according to the model.
2. The optical fiber coupling method according to claim 1, wherein in the third step, the diameter of the micro-nano optical fiber is controlled within the diameter range by using a tapering method.
3. The optical fiber coupling method according to claim 1, wherein the third step further comprises the step of sleeving a micro-nano optical fiber with a micro-pipe.
4. The optical fiber coupling method according to claim 3, wherein the third step further comprises a step of applying an adhesive between the micro-nano optical fiber and the microtube.
5. The method of coupling optical fibers according to claim 1, wherein the diameter is in the range of 5.2-6.5 μm.
6. The optical fiber coupling method according to claim 1, wherein the third step further comprises a step of grinding and polishing the emergent end face of the micro-nano optical fiber.
7. The optical fiber coupling method according to claim 1, wherein the fourth step further comprises a step of curing the micro-nano optical fiber on the waveguide.
8. The optical fiber coupling method according to claim 1, wherein an antireflection film is provided on the end face of the waveguide.
9. The method of coupling optical fibers of any one of claims 1-8, wherein the model is a mathematical model.
10. The optical fiber coupling method according to claim 9, wherein in the mathematical model, a refractive index of a surface medium of the micro-nano optical fiber is set according to a refractive index of an adhesive applied between the micro-nano optical fiber and a microtube.
11. The optical fiber coupling method according to claim 10, wherein in the mathematical model, the refractive index of the surface medium of the micro-nanofiber is set to 1.38.
12. A periodically poled lithium niobate waveguide device comprising a periodically poled lithium niobate waveguide and a micro-nanofiber, the micro-nanofiber being directly coupled with the waveguide by the fiber coupling method according to any one of claims 1 to 11.
13. An up-conversion single photon detector comprising the periodically poled lithium niobate waveguide device of claim 12.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811153884.9A CN110967790B (en) | 2018-09-30 | 2018-09-30 | Optical fiber coupling method for PPLN waveguide device, waveguide device and single photon detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811153884.9A CN110967790B (en) | 2018-09-30 | 2018-09-30 | Optical fiber coupling method for PPLN waveguide device, waveguide device and single photon detector |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110967790A CN110967790A (en) | 2020-04-07 |
| CN110967790B true CN110967790B (en) | 2021-12-31 |
Family
ID=70028300
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811153884.9A Active CN110967790B (en) | 2018-09-30 | 2018-09-30 | Optical fiber coupling method for PPLN waveguide device, waveguide device and single photon detector |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110967790B (en) |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1971394A (en) * | 2006-12-01 | 2007-05-30 | 华中科技大学 | Transfer device of all-optical wavelength based on lithium niobate fiber waveguide ring antrum |
| CN102804012A (en) * | 2009-09-21 | 2012-11-28 | 康宁股份有限公司 | Methods for passively aligning opto-electronic component assemblies on substrates |
| CN103011607A (en) * | 2012-12-27 | 2013-04-03 | 南京邮电大学 | Long-distance micro/nano-core glass optical fiber and preparation method thereof |
| CN203287647U (en) * | 2013-06-21 | 2013-11-13 | 武汉光迅科技股份有限公司 | Lithium niobate modulator |
| WO2014042704A1 (en) * | 2012-09-17 | 2014-03-20 | Winarski Tyson | Nanotube fiber optic cable |
| CN203981922U (en) * | 2014-07-30 | 2014-12-03 | 山东量子科学技术研究院有限公司 | Periodically poled lithium niobate waveguide device based on both-end coupling fiber |
| CN105339825A (en) * | 2013-06-28 | 2016-02-17 | Toto株式会社 | Optical receptacle |
| CN205539860U (en) * | 2016-02-23 | 2016-08-31 | 江苏西贝电子网络有限公司 | Full light modulator of graphite alkene - optic fibre composite construction that receives a little |
| CN206618929U (en) * | 2017-04-21 | 2017-11-07 | 北京京东方光电科技有限公司 | A kind of backlight module, display module and display device |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2819594B1 (en) * | 2001-01-15 | 2003-05-16 | Opsitech Optical System Chip | OPTICAL STRUCTURE WITH INSULATED BEAM AND MANUFACTURING METHOD THEREOF |
| CN103513335B (en) * | 2013-10-09 | 2017-03-15 | 中南大学 | A kind of array waveguide device alignment methods and device based on coupling model |
| CN104836620A (en) * | 2015-03-31 | 2015-08-12 | 上海电缆研究所 | Optical waveguide array-optical fiber array automatic butt-coupling parallel index optimization method |
-
2018
- 2018-09-30 CN CN201811153884.9A patent/CN110967790B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1971394A (en) * | 2006-12-01 | 2007-05-30 | 华中科技大学 | Transfer device of all-optical wavelength based on lithium niobate fiber waveguide ring antrum |
| CN102804012A (en) * | 2009-09-21 | 2012-11-28 | 康宁股份有限公司 | Methods for passively aligning opto-electronic component assemblies on substrates |
| WO2014042704A1 (en) * | 2012-09-17 | 2014-03-20 | Winarski Tyson | Nanotube fiber optic cable |
| CN103011607A (en) * | 2012-12-27 | 2013-04-03 | 南京邮电大学 | Long-distance micro/nano-core glass optical fiber and preparation method thereof |
| CN203287647U (en) * | 2013-06-21 | 2013-11-13 | 武汉光迅科技股份有限公司 | Lithium niobate modulator |
| CN105339825A (en) * | 2013-06-28 | 2016-02-17 | Toto株式会社 | Optical receptacle |
| CN203981922U (en) * | 2014-07-30 | 2014-12-03 | 山东量子科学技术研究院有限公司 | Periodically poled lithium niobate waveguide device based on both-end coupling fiber |
| CN205539860U (en) * | 2016-02-23 | 2016-08-31 | 江苏西贝电子网络有限公司 | Full light modulator of graphite alkene - optic fibre composite construction that receives a little |
| CN206618929U (en) * | 2017-04-21 | 2017-11-07 | 北京京东方光电科技有限公司 | A kind of backlight module, display module and display device |
Non-Patent Citations (1)
| Title |
|---|
| 基于微纳光纤的量子器件研究;徐颖鑫;《中国博士学位论文全文数据库》;20180331;全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110967790A (en) | 2020-04-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20180120504A1 (en) | Optical coupler having subwavelength grating | |
| WO2022088228A1 (en) | End face coupler and semiconductor device | |
| US20060182402A1 (en) | Multiple-core planar optical waveguides and methods of fabrication and use thereof | |
| WO2015167946A1 (en) | Grating-coupler assembly with small mode-field diameter for photonic-integrated-circuit systems | |
| JP2020534566A (en) | Methods and equipment for self-aligned connections of optical fibers to waveguides in photonic integrated circuits | |
| Mahmoud et al. | Lithium niobate on insulator (LNOI) grating couplers | |
| CN210666088U (en) | Silicon optical mode spot mode converter | |
| JP3875452B2 (en) | Mode converter and method | |
| CN106291821B (en) | Hollow-core photonic crystal fiber coupler | |
| Zhou et al. | Monolithically integrated active passive waveguide array fabricated on thin film lithium niobate using a single continuous photolithography process | |
| CN103499855B (en) | Photonic crystal optical fiber coupler and manufacturing method thereof | |
| CN106840361B (en) | Echo wall mode resonator with stable operation | |
| CN114690315A (en) | Waveguide-to-optical fiber three-dimensional polymer horizontal lens coupler | |
| CN110967790B (en) | Optical fiber coupling method for PPLN waveguide device, waveguide device and single photon detector | |
| CN111308612B (en) | Method for preparing inverse MMI type waveguide Mach-Zehnder interferometer | |
| CN111025475B (en) | Method for manufacturing Y waveguide based on refractive index guide type photonic crystal fiber | |
| CN103837929B (en) | A kind of WGM element method for making | |
| CN115079341B (en) | Waveguide device | |
| WO2020080196A1 (en) | Optical connection structure | |
| CN111367019A (en) | Optical waveguide coupling method based on optical fiber cone | |
| CN109814207B (en) | Echo wall resonator with optical fiber embedded with microsphere on side surface | |
| JP2896947B2 (en) | Optical fiber end structure and method of manufacturing the same | |
| US10338325B1 (en) | Nanofiller in an optical interface | |
| CN217718152U (en) | Waveguide device | |
| CN211454022U (en) | PPLN waveguide coupling structure based on gyro optical fiber |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |