WO2023103610A1 - 基于SiON起偏器的光纤陀螺用SiN基集成光学芯片 - Google Patents

基于SiON起偏器的光纤陀螺用SiN基集成光学芯片 Download PDF

Info

Publication number
WO2023103610A1
WO2023103610A1 PCT/CN2022/126677 CN2022126677W WO2023103610A1 WO 2023103610 A1 WO2023103610 A1 WO 2023103610A1 CN 2022126677 W CN2022126677 W CN 2022126677W WO 2023103610 A1 WO2023103610 A1 WO 2023103610A1
Authority
WO
WIPO (PCT)
Prior art keywords
fiber
waveguide
mode converter
sion
waveguide mode
Prior art date
Application number
PCT/CN2022/126677
Other languages
English (en)
French (fr)
Inventor
刘晓平
吕海斌
Original Assignee
深圳市奥斯诺工业有限公司
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 深圳市奥斯诺工业有限公司 filed Critical 深圳市奥斯诺工业有限公司
Publication of WO2023103610A1 publication Critical patent/WO2023103610A1/zh

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
    • G01C19/00—Gyroscopes; Turn-sensitive devices using vibrating masses; Turn-sensitive devices without moving masses; Measuring angular rate using gyroscopic effects
    • G01C19/58—Turn-sensitive devices without moving masses
    • G01C19/64—Gyrometers using the Sagnac effect, i.e. rotation-induced shifts between counter-rotating electromagnetic beams
    • G01C19/72—Gyrometers using the Sagnac effect, i.e. rotation-induced shifts between counter-rotating electromagnetic beams with counter-rotating light beams in a passive ring, e.g. fibre laser gyrometers
    • G01C19/721—Details
    • 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
    • G02B6/14—Mode converters
    • 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
    • G02B6/27—Optical coupling means with polarisation selective and adjusting means

Definitions

  • the invention relates to the technical field of integrated optics and inertial sensing, in particular to a silicon nitride (SiN)-based integrated optical chip for a fiber optic gyroscope based on a silicon nitride oxide (SiON) polarizer.
  • SiN silicon nitride
  • SiON silicon nitride oxide
  • high-sensitivity gyroscopes play a vital role in a series of fields, such as aviation navigation, robotics, unmanned vehicle driving, and geographic mapping. wide range of needs.
  • the optical gyroscope based on the Sagnac effect has attracted extensive attention due to its high sensitivity, and has developed into a multi-purpose mature technology.
  • the optical gyroscope has no motion module, so it is not affected by gravity, shock and vibration, which means that no special gimbal suspension or packaging method is required.
  • a typical fiber optic gyroscope mainly consists of three components: a passive sensing fiber optic coil, active and passive components (such as light source, phase modulator, photodetector, and coupler), and a readout circuit.
  • an integrated optical driver chip is formed, which can be used with the sensing coil, such as passive optical fiber or ultra-low loss silicon nitride waveguide , connected together to form an interference optical gyroscope.
  • the integrated driver chip greatly reduces the size, weight, power consumption and production cost of the optical gyroscope, thus playing an important role in promoting the popularization of the optical gyroscope.
  • the integrated optical chip widely used in the fiber optic gyroscope system is the integrated chip based on lithium niobate (LiNbO 3 ) material. It integrates Y-type beam splitter, polarizer and phase modulator on the same chip, and is mainly used for closed-loop fiber optic gyroscopes with different precisions, so as to realize closed-loop feedback of interference phase, reduce the influence of device drift, and have higher precision high.
  • LiNbO 3 lithium niobate
  • lithium niobate optical waveguide is the proton exchange method, and the proton exchange time, temperature, characteristics of the exchange medium and The temperature and time of annealing have strict requirements, the preparation process is complicated and the cost is high; (2) the thermo-optic coefficient of the material is large; when light passes through the LiNbO 3 material, due to the change of the ambient temperature, the optical transmission characteristics of the device will be affected, This results in a temperature drift effect. Therefore, in order to ensure the stability of the device in a wide temperature range, temperature compensation measures must be taken, which makes the peripheral control circuit more complicated.
  • the technical problem to be solved by the embodiments of the present invention is to provide a SiN-based integrated optical chip for a fiber optic gyroscope based on a SiON polarizer, so as to effectively improve its stability and reliability.
  • the embodiment of the present invention proposes a SiN-based integrated optical chip for fiber optic gyroscope based on SiON polarizer, including a first fiber-waveguide mode converter, a second fiber-waveguide mode converter, a first 3dB coupler, SiON polarizer, second 3dB coupler, third fiber-waveguide mode converter, fourth fiber-waveguide mode converter;
  • One end of the first fiber-waveguide mode converter is connected to an external light source through an optical fiber, and the other end of the first fiber-waveguide mode converter is connected to a branch of the first 3dB coupler; one end of the second fiber-waveguide mode converter is connected to an external light source through an optical fiber.
  • the external photodetector is connected, the other end of the second fiber-waveguide mode converter is connected with the other branch of the first 3dB coupler; the base waveguide of the first 3dB coupler is connected with one end of the SiON polarizer; the SiON polarizer
  • the other end of the second 3dB coupler is connected to the base waveguide; one branch of the second 3dB coupler is connected to one end of the third fiber-waveguide mode converter, and the other branch of the second 3dB coupler is connected to the fourth fiber-waveguide mode
  • One end of the converter is connected; the other end of the third fiber-waveguide mode converter is connected with one end of the external fiber ring; the other end of the fourth fiber-waveguide mode converter is connected with the other end of the external fiber ring.
  • first fiber-waveguide mode converter, the second fiber-waveguide mode converter, the third fiber-waveguide mode converter and the fourth fiber-waveguide mode converter all use inversed tape
  • the structure realizes matching with the mode field diameter of the input polarization maintaining fiber, and the working wavelength range is 800-900nm.
  • both the first 3dB coupler and the second 3dB coupler are realized by using a 1 ⁇ 2 MMI coupler or a Y-type beam splitter, and the working wavelength range is 800-900nm.
  • the structural composition of the SiON polarizer is, from top to bottom, the SiO 2 upper cladding layer, the SiON upper cladding layer, the SiO 2 intermediate layer, the SiN waveguide, the SiO 2 lower cladding layer and the Si substrate.
  • the thickness of the SiON upper cladding is ⁇ 1mm, and its width perpendicular to the direction of the SiN waveguide is ⁇ 3mm; the thickness of the SiN waveguide is consistent with the thickness of the waveguide of the fiber-waveguide mode converter.
  • the fiber optic gyro based on the SiN optical integrated chip has a larger scale factor in the short wavelength region.
  • SiN is a mature material in the microelectronics industry and is used as an electrical and thermal insulator in circuits.
  • the manufacturing technology related to the SiN process is relatively mature.
  • SiN also has a range of excellent optical properties, making it ideal for many integrated photonic device applications.
  • Fig. 1 (a) is a top view of the fiber-waveguide mode converter according to the embodiment of the present invention, and (b) is a cross-sectional view of the fiber-waveguide mode converter according to the embodiment of the present invention.
  • Fig. 2 is a schematic structural diagram of a Y-shaped beam splitter according to an embodiment of the present invention.
  • (a) is a top view of a SiON polarizer
  • (b) is a cross-sectional view of a SiON polarizer in FIG. 3 .
  • Fig. 4 is a schematic structural diagram of a SiN-based integrated optical chip for a fiber optic gyroscope based on a SiON polarizer according to an embodiment of the present invention.
  • the SiN-based integrated optical chip for fiber optic gyroscopes based on SiON polarizers includes a first fiber-waveguide mode converter 1-1, a second fiber-waveguide mode converter 1- 2.
  • first fiber-waveguide mode converter 1-1 is connected to an external light source through an optical fiber, and the other end of the first fiber-waveguide mode converter 1-1 is connected to a branch of the first 3dB coupler 2; the second fiber-waveguide One end of the mode converter 1-2 is connected to an external photodetector through an optical fiber, and the other end of the second fiber-waveguide mode converter 1-2 is connected to another branch of the first 3dB coupler 2 .
  • the base waveguide of the first 3dB coupler 2 is connected to one end of the SiON polarizer; the other end of the SiON polarizer is connected to the base waveguide of the second 3dB coupler 6 .
  • a branch of the second 3dB coupler 6 is connected to one end of the third fiber-waveguide mode converter 7-1, and another branch of the second 3dB coupler 6 is connected to one end of the fourth fiber-waveguide mode converter 7-2;
  • the other end of the three fiber-waveguide mode converter 7-1 is connected to one end of the external fiber ring; the other end of the fourth fiber-waveguide mode converter 7-2 is connected to the other end of the external fiber ring.
  • the light output by the external light source is coupled to the first fiber-waveguide mode converter 1-1 on the chip along the direction indicated by the arrow 8 through the optical fiber, and the light output by the first fiber-waveguide mode converter 1-1 Contains two different polarization modes (quasi TE 0 and TM 0 ); after passing through the first 3dB coupler 2, the two different polarization modes enter the SiON polarizer through the curved waveguide A3, due to the polarization selection of the polarizer, the The quasi-TM 0 mode has leaked into the SiON cladding layer 4-2, while only the quasi-TE 0 mode is retained in the SiN waveguide 4-1; the TE 0 mode enters the second 3dB coupler 6 through the curved waveguide B5, and is split into two beams via After the third optical fiber-waveguide mode converter 7-1 and the fourth optical fiber-waveguide mode converter 7-2, they are coupled into the optical fiber ring; the two beams of light are propagated counterclockwise and counterclockwise in the optical fiber ring respectively,
  • the optical fiber rotates around its central axis, the Sagnac effect is generated, and the intensity of the interference light returning to the second 3dB coupler 6 changes;
  • the curved waveguide A3, the first 3dB coupler 2, and the second fiber-waveguide mode converter 1-2 it is coupled to an external photodetector to detect the changing light intensity, and it can be rotated after processing angular velocity information.
  • the first fiber-waveguide mode converter, the second fiber-waveguide mode converter, the third fiber-waveguide mode converter and the fourth fiber-waveguide mode converter are all
  • the inversed taper structure is used to match the mode field diameter of the input polarization-maintaining fiber, and the working wavelength range is 800-900nm.
  • the working wavelength range is 800-900nm.
  • Figure 1 taking an ultra-fine polarization maintaining fiber as an example, its cladding diameter is 40um and the core diameter is 3um.
  • the mode field diameter of the quasi-TE 0 mode in the fiber is about 3.7um;
  • the optimal waveguide width is 130nm, corresponding to the The mode field diameter of the quasi-TE 0 mode at 830nm is about 3.7um, so that the mode field matching is realized.
  • the thickness of the SiN waveguide is 180nm
  • the width of the waveguide at the input end is 130nm
  • the mode field diameter corresponding to the quasi-TE 0 mode in the waveguide is about 3.7um at 830nm.
  • the length of the straight waveguide at the input end is 20um
  • the length of the taper is 100um
  • the width of the waveguide at the output end is 550nm.
  • both the first 3dB coupler 2 and the second 3dB coupler 6 are realized by using a 1 ⁇ 2 MMI coupler or a Y-type beam splitter, and the working wavelength range is 800-900nm.
  • the boundary of the Y-shaped beam splitter is optimized based on the principle of reverse design, and the distance between the two output ports is increased under the premise of ensuring the forward transmittance. interval, and suppress the retroreflection, and its structural design is shown in Figure 2.
  • the thickness of the SiN waveguide is 180nm
  • the length of the coupling region is 4um
  • the discrete width values used to generate the continuous boundary distribution uniformly distributed in the coupling region are 0.55, 0.65, 0.76, 0.93, 1.29, 1.75 , 1.65, 1.58, 1.52, 1.42, 1.4, 1.3um
  • the distance between the two arms is 0.2um.
  • the structural composition of the SiON polarizer is, from top to bottom, an SiO 2 upper cladding layer, a SiON upper cladding layer, a SiO 2 intermediate layer, a SiN waveguide, a SiO 2 lower cladding layer, and a Si substrate.
  • the design principle of the polarizer is: within the target operating wavelength range of 800-900nm, reasonably select the size of the waveguide so that it only supports two quasi-TE 0 /TM 0 modes; introduce an upcoupled SiON slab waveguide, and adjust the SiON
  • the refractive index (making it between the effective refractive index of the quasi-TE 0 /TM 0 mode) and the size of the distance from the SiN waveguide maximize the coupling between the quasi-TM 0 mode and the upper slab waveguide mode, so that the TM 0
  • the mode field distribution of the mode extends into the slab SiON waveguide, thereby greatly reducing its energy distribution ratio in the SiN waveguide; on the other hand, it ensures that the coupling between the quasi-TE 0 mode and the slab waveguide mode is weak, so that its energy is mainly concentrated inside the SiN waveguide.
  • the size of the SiN waveguide is 550nm ⁇ 180nm
  • the thickness of the SiON layer is 1mm
  • the width in the direction perpendicular to the waveguide is 3mm
  • the distance from the SiN waveguide is 200nm.
  • the thickness of the SiON upper cladding layer, the thickness of the SiO2 intermediate layer, and the width and height of the SiN waveguide respectively meet: the thickness of the SiON upper cladding layer ⁇ 1mm, and its width perpendicular to the direction of the SiN waveguide ⁇ 3mm; the thickness of the SiN waveguide Keep consistent with the waveguide thickness of the fiber-waveguide mode converter; select the appropriate SiN waveguide width to ensure that only two modes TE 0 and TM 0 are supported in the waveguide and the effective refractive index difference between the two is as large as possible, and the reasonable value range is [400nm, 600nm]; the choice of the thickness of the SiO 2 interlayer is related to the geometry of the SiN waveguide to ensure that the energy distribution ratios of the TE 0 and TM 0 modes in the upper SiON layer are as large as possible. 180nm as an example, the suitable SiO 2 interlayer thickness is 200nm.
  • the invention can effectively improve its stability and reliability, improve multiple performances of the open-loop fiber optic gyroscope, and realize the miniaturization, lower power consumption and lower cost of the open-loop fiber optic gyroscope , Simpler structure design and process.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Engineering & Computer Science (AREA)
  • Electromagnetism (AREA)
  • Power Engineering (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Gyroscopes (AREA)

Abstract

一种基于SiON起偏器的光纤陀螺用SiN基集成光学芯片，包括第一光纤-波导模式转换器(1-1)、第二光纤-波导模式转换器(1-2)、第一3dB耦合器(2)、SiON起偏器、第二3dB耦合器(6)以及第三光纤-波导模式转换器(7-1)、第四光纤-波导模式转换器(7-2)。在保证开环光纤陀螺精度的同时，可有效提高其稳定性、可靠性，实现开环光纤陀螺的更小型化、更低功耗、更低成本、更简单结构设计及工艺。

Description

基于SiON起偏器的光纤陀螺用SiN基集成光学芯片
本申请要求于2021年12月06日提交中国专利局、申请号为202111472069.0、发明名称为“基于SiON起偏器的光纤陀螺用SiN基集成光学芯片”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
本发明涉及集成光学和惯性传感技术领域，尤其涉及一种基于氮氧化硅(SiON)起偏器的光纤陀螺用氮化硅(SiN)基集成光学芯片。
背景技术
由于可以精确测量角位移，高灵敏度的陀螺仪在一系列领域中，如航空导航、机器人、无人汽车驾驶以及地理测绘等，发挥着至关重要的作用，低廉紧凑的陀螺仪更是受到市场的广泛需求。基于Sagnac效应的光学陀螺由于其高灵敏度受到了广泛的关注，已经发展成为了一项多用途的成熟技术。相比传统基于角动量守恒的机械陀螺，光学陀螺没有运动模块，因此不受重力、冲击和振动的影响，从而也意味着不需要任何特殊的万向悬挂架或者封装手段。
随着用于通信领域的低损耗单模光纤以及各种光纤器件的快速发展，将其应用在光学陀螺中就催生了全光纤的光学陀螺。作为光学陀螺的典型代表，光纤陀螺目前已经发展成为具有高灵敏度、高稳定性、可信赖的成熟技术手段，具有比最先进的微机电陀螺更好的性能表现，且具有更低的成本、功耗以及尺寸。典型的光纤光学陀螺主要包括三个组成部分：被动传感光纤线圈、有源无源器件(如光源、相位调制器、光电探测器和耦合器)以及读出电路。为了不断完善被动传感部分，近年来研究者们开展了大量的相关研究，发明了一系列新型光纤，如具有极低非线性和热效应的空心光纤以及高偏振消光比光纤。另外，更加复杂的光纤缠绕技术不断被开发出来，以消除由热梯度和振动带来的非互易噪声和漂移。进一步的发展还包括采用更薄的包层或者多芯光纤，从而显著减少传感光纤线圈的尺寸，但依然保持较高的灵敏度。
然而，目前大部分光纤陀螺均采用分离的光学器件来实现光信号的产 生、调制以及探测，而这些分离的光学器件通常通过尾纤相互连接在一起，从而形成Sagnac干涉光学回路。尽管采用分离器件提供了可以选择不同器件的自由度，但同样导致了一系列的问题，如寄生反射、连接点处增加的插入损耗以及对环境敏感的偏振失配等，上述情况均会不同程度的降低系统性能。尽管通过采用如模式和偏振滤光器件可以尽可能的减少上述效应的影响，但是额外增加了封装成本。另外，采用一系列分离光学器件还会增大系统尺寸以及重量。
为了避免上述采用分离器件引入的寄生反射、连接点处增加的插入损耗以及对环境敏感的偏振失配等，近年来，随着集成光子学的发展，研究者们提出了集成光学陀螺。通过将除传感线圈外光学陀螺需要的所有有源和无源光学器件进行集成，即构成集成光学驱动芯片，该驱动芯片可以同传感线圈，如被动光纤或超低损耗的氮化硅波导，连接在一起形成干涉光学陀螺。这样以来，该集成驱动芯片大大减少了光学陀螺的尺寸、重量、功耗以及制作成本，从而将为光学陀螺的普及起到重要的推动作用。
目前在光纤陀螺系统中得到广泛应用的集成光学芯片是基于铌酸锂(LiNbO 3)材料的集成芯片。其在同一个芯片上集成了Y型分束器、起偏器和相位调制器，主要用于不同精度下的闭环光纤陀螺，从而实现干涉相位的闭环反馈，降低了器件漂移的影响，精度较高。另一方面，在实际应用中，基于铌酸锂材料的集成芯片也存在一些不足：(1)铌酸锂光波导制作方法为质子交换法，对质子交换的时间、温度、交换介质的特性及退火的温度和时间有严格要求，制备工艺复杂且成本较高；(2)材料的热光系数较大；当光通过LiNbO 3材料时，由于环境温度的变化，会影响器件的光学传输特性，从而产生温度漂移效应。因此，为了保证器件在宽温度范围内的工作稳定性，必须采取温度补偿措施，使得外围控制电路比较复杂。
发明内容
本发明实施例所要解决的技术问题在于，提供一种基于SiON起偏器的光纤陀螺用SiN基集成光学芯片，以有效提高其稳定性、可靠性。
为了解决上述技术问题，本发明实施例提出了一种基于SiON起偏器的光纤陀螺用SiN基集成光学芯片，包括第一光纤-波导模式转换器、第 二光纤-波导模式转换器、第一3dB耦合器、SiON起偏器、第二3dB耦合器以及第三光纤-波导模式转换器、第四光纤-波导模式转换器；
第一光纤-波导模式转换器一端通过光纤与外部光源相连，第一光纤-波导模式转换器的另一端与第一3dB耦合器的一个分支相连；第二光纤-波导模式转换器一端通过光纤与外部光电探测器相连，第二光纤-波导模式转换器的另一端与第一3dB耦合器的另一个分支相连；第一3dB耦合器的基波导与SiON起偏器的一端相连；SiON起偏器的另一端与第二3dB耦合器的基波导相连；第二3dB耦合器的一个分支与第三光纤-波导模式转换器一端相连，第二3dB耦合器的另一个分支与第四光纤-波导模式转换器一端相连；第三光纤-波导模式转换器的另一端与外部光纤环一端相连；第四光纤-波导模式转换器的另一端与外部光纤环另一端相连。
进一步地，所述第一光纤-波导模式转换器、所述第二光纤-波导模式转换器、所述第三光纤-波导模式转换器和所述第四光纤-波导模式转换器均采用inversed taper结构实现与输入保偏光纤的模场直径匹配，工作波长范围为800-900nm。
进一步地，所述第一3dB耦合器和所述第二3dB耦合器均采用1×2MMI耦合器或者Y型分束器实现，工作波长范围为800-900nm。
进一步地，所述SiON起偏器的结构组成从上到下依次为SiO 2上包层、SiON上包层、SiO 2中间层、SiN波导、SiO 2下包层和Si衬底。
进一步地，SiON上包层厚度≥1mm，其垂直于SiN波导方向上的宽度≥3mm；SiN波导厚度与光纤-波导模式转换器的波导厚度保持一致。
本发明的有益效果为：
1、由于SiN波导在800-900nm波长区域具有高的透射特性，使得基于SiN光学集成芯片的光纤陀螺在短波长区域具有更大的标度因子。
2、在SiN波导中可以实现较大的双折射，而具有高双折射的波导可以提供较好的相位误差抑制。
3、SiN是微电子工业中一种成熟的材料，在电路中被用作电绝缘体和热绝缘体。与SiN工艺相关的制造技术较为成熟。SiN还具有一系列优异的光学特性，使其成为许多集成光子器件应用的理想选择。
4、提升了开环光纤陀螺的温度稳定性及可靠性，实现开环光纤陀螺 的小型化。由于SiN材料的热光系数较小，从而使得环境温度的变化对器件的光学传输特性影响较小，进而一定程度上抑制了温度漂移效应，提高了陀螺的温度稳定性。另外，通过集成光波导和器件，避免了采用分离器件引入的寄生反射、连接点处增加的插入损耗以及对环境敏感的偏振失配等，进一步提高了系统的可靠性，并且减小了体积，适合小型化开环光纤陀螺的集成，也使得开环光纤陀螺的成本进一步降低。
说明书附图
图1中(a)是本发明实施例的光纤-波导模式转换器的俯视图，(b)是本发明实施例的光纤-波导模式转换器的横截面图。
图2是本发明实施例的Y型分束器的结构示意图。
图3中(a)是SiON起偏器的俯视图，(b)是SiON起偏器的横截面图。
图4是本发明实施例的基于SiON起偏器的光纤陀螺用SiN基集成光学芯片的结构示意图。
附图标号说明：
第一光纤-波导模式转换器1-1，第二光纤-波导模式转换器1-2，第一3dB耦合器2，弯曲波导A3，SiN波导4-1，SiON包层4-2，弯曲波导B5，第二3dB耦合器6，第三光纤-波导模式转换器7-1，第四光纤-波导模式转换器7-2，标号8的箭头方向为外部光源输出的光的方向，标号9的箭头方向为输出到外部光纤环的光的方向。
具体实施方式
需要说明的是，在不冲突的情况下，本申请中的实施例及实施例中的特征可以相互结合，下面结合附图和具体实施例对本发明作进一步详细说明。
请参照图1～图4，本发明实施例的基于SiON起偏器的光纤陀螺用SiN基集成光学芯片包括第一光纤-波导模式转换器1-1、第二光纤-波导模式转换器1-2、第一3dB耦合器2、SiON起偏器、第二3dB耦合器6以及第三光纤-波导模式转换器7-1、第四光纤-波导模式转换器7-2。
第一光纤-波导模式转换器1-1一端通过光纤与外部光源相连，第一光纤-波导模式转换器1-1的另一端与第一3dB耦合器2的一个分支相连； 第二光纤-波导模式转换器1-2一端通过光纤与外部光电探测器相连，第二光纤-波导模式转换器1-2的另一端与第一3dB耦合器2的另一个分支相连。第一3dB耦合器2的基波导与SiON起偏器的一端相连；SiON起偏器的另一端与第二3dB耦合器6的基波导相连。第二3dB耦合器6的一个分支与第三光纤-波导模式转换器7-1一端相连，第二3dB耦合器6的另一个分支与第四光纤-波导模式转换器7-2一端相连；第三光纤-波导模式转换器7-1的另一端与外部光纤环一端相连；第四光纤-波导模式转换器7-2的另一端与外部光纤环另一端相连。
参照图4所示，外部光源输出的光经光纤沿箭头8标识的方向耦合到芯片上的第一光纤-波导模式转换器1-1，第一光纤-波导模式转换器1-1输出的光包含两种不同的偏振模式(准TE 0和TM 0)；两种不同的偏振模式通过第一3dB耦合器2后，通过弯曲波导A3进入SiON起偏器，由于起偏器的偏振选择，将准TM 0模式泄露到了SiON包层4-2中，而在SiN波导4-1中只保留了准TE 0模式；该TE 0模式通过弯曲波导B5进入第二3dB耦合器6，分成两束经第三光纤-波导模式转换器7-1和第四光纤-波导模式转换器7-2后，耦合进入光纤环；这两束光在光纤环中分别沿顺时针和逆时针方向相向传播，且两束光满足相干条件。当光纤环绕其中心轴发生转动后，产生了Sagnac效应，从而回到第二3dB耦合器6处的干涉光强发生变化；该干涉光信号经第二3dB耦合器6、弯曲波导B5、SiON起偏器、弯曲波导A3、第一3dB耦合器2、第二光纤-波导模式转换器1-2后，耦合输出到外部的光电探测器，从而检测出变化的光强，经处理后即得转动角速度信息。
作为一种实施方式，所述第一光纤-波导模式转换器、所述第二光纤-波导模式转换器、所述第三光纤-波导模式转换器和所述第四光纤-波导模式转换器均采用inversed taper结构实现与输入保偏光纤的模场直径匹配，工作波长范围为800-900nm。如图1所示，以超细径保偏光纤为例，其包层直径为40um，纤芯直径为3um，在波长830nm处，光纤中的准TE 0模式的模场直径约为3.7um；对于inversed taper结构，在固定波导厚度情况下，通过优化输入端波导的宽度，可实现与光纤模场直径的匹配，以波导厚度为180nm为例，此时最优波导宽度为130nm，对应波导中的准TE 0 模式在830nm下的模场直径约为3.7um，从而实现了模场匹配，当taper长度足够长时，可实现约80％的耦合效率，模式串扰可以忽略不计。在该实施例中，SiN波导厚度为180nm，输入端波导宽度为130nm，对应波导中的准TE 0模式在830nm下的模场直径约为3.7um。输入端直波导长度为20um，taper长度为100um，输出端波导宽度为550nm。
作为一种实施方式，所述第一3dB耦合器2和所述第二3dB耦合器6均采用1×2MMI耦合器或者Y型分束器实现，工作波长范围为800-900nm。其中，为了减少寄生反射以及降低加工误差，基于反向设计原理对所述Y型分束器的边界进行了优化，在保证前向透过率的前提下，增大了两个输出端口间的间隔，并抑制了后向反射，其结构设计如图2所示。在该实施例中，SiN波导厚度为180nm，耦合区域的长度为4um，在该耦合区域中均匀分布的用于产生连续边界分布的离散宽度值分别为0.55、0.65、0.76、0.93、1.29、1.75、1.65、1.58、1.52、1.42、1.4、1.3um，两臂之间的距离为0.2um。
作为一种实施方式，所述SiON起偏器的结构组成从上到下依次为SiO 2上包层、SiON上包层、SiO 2中间层、SiN波导、SiO 2下包层和Si衬底。所述起偏器设计原理为：在目标工作波长范围800-900nm内，合理选择波导尺寸，使其仅支持准TE 0/TM 0两个模式；引入上耦合的SiON平板波导，通过调节SiON的折射率(使其介于准TE 0/TM 0模式的有效折射率之间)以及与SiN波导的间隔大小，尽可能增大准TM 0模式与上方平板波导模式间的耦合，从而使得TM 0模式的模场分布扩展至平板SiON波导内，进而极大降低其在SiN波导内的能量分布比例；另一方面，确保准TE 0模式与平板波导模式间的耦合较弱，使其能量主要集中在SiN波导内。在该实施例中，SiN波导尺寸为550nm×180nm，SiON层的厚度为1mm，其垂直于波导的方向上的宽度为3mm，与SiN波导之间的距离为200nm。
作为一种实施方式，SiON上包层厚度、SiO 2中间层厚度以及SiN波导的宽度和高度分别满足：SiON上包层厚度≥1mm，其垂直于SiN波导方向上的宽度≥3mm；SiN波导厚度与光纤-波导模式转换器的波导厚度保持一致；选择合适的SiN波导宽度以确保波导内仅支持TE 0、TM 0两个模 式且二者的有效折射率差尽可能大，合理的取值范围为[400nm,600nm]；SiO 2中间层厚度的选择与SiN波导的几何尺寸有关，以确保TE 0、TM 0两个模式在上方SiON层中的能量分布占比相差尽可能大，以550nm×180nm为例，合适的SiO 2中间层厚度为200nm。
本发明在保证开环光纤陀螺精度的同时，可有效提高其稳定性、可靠性，提高开环光纤陀螺的多项性能，实现开环光纤陀螺的更小型化、更低功耗、更低成本、更简单结构设计及工艺。
尽管已经示出和描述了本发明的实施例，对于本领域的普通技术人员而言，可以理解在不脱离本发明的原理和精神的情况下可以对这些实施例进行多种变化、修改、替换和变型，本发明的范围由所附权利要求及其等同范围限定。

Claims (5)

  1. 一种基于SiON起偏器的光纤陀螺用SiN基集成光学芯片，其特征在于，包括第一光纤-波导模式转换器、第二光纤-波导模式转换器、第一3dB耦合器、SiON起偏器、第二3dB耦合器以及第三光纤-波导模式转换器、第四光纤-波导模式转换器；
    第一光纤-波导模式转换器一端通过光纤与外部光源相连，第一光纤-波导模式转换器的另一端与第一3dB耦合器的一个分支相连；第二光纤-波导模式转换器一端通过光纤与外部光电探测器相连，第二光纤-波导模式转换器的另一端与第一3dB耦合器的另一个分支相连；第一3dB耦合器的基波导与SiON起偏器的一端相连；SiON起偏器的另一端与第二3dB耦合器的基波导相连；第二3dB耦合器的一个分支与第三光纤-波导模式转换器一端相连，第二3dB耦合器的另一个分支与第四光纤-波导模式转换器一端相连；第三光纤-波导模式转换器的另一端与外部光纤环一端相连；第四光纤-波导模式转换器的另一端与外部光纤环另一端相连。
  2. 如权利要求1所述的基于SiON起偏器的光纤陀螺用SiN基集成光学芯片，其特征在于，所述第一光纤-波导模式转换器、所述第二光纤-波导模式转换器、所述第三光纤-波导模式转换器和所述第四光纤-波导模式转换器均采用inversed taper结构实现与输入保偏光纤的模场直径匹配，工作波长范围为800-900nm。
  3. 如权利要求1所述的基于SiON起偏器的光纤陀螺用SiN基集成光学芯片，其特征在于，所述第一3dB耦合器和所述第二3dB耦合器均采用1×2MMI耦合器或者Y型分束器实现，工作波长范围为800-900nm。
  4. 如权利要求1所述的基于SiON起偏器的光纤陀螺用SiN基集成光学芯片，其特征在于，所述SiON起偏器的结构组成从上到下依次为SiO 2上包层、SiON上包层、SiO 2中间层、SiN波导、SiO 2下包层和Si衬底。
  5. 如权利要求4所述的基于SiON起偏器的光纤陀螺用SiN基集成光学芯片，其特征在于，SiON上包层厚度≥1mm，其垂直于SiN波导方向上的宽度≥3mm；SiN波导厚度与光纤-波导模式转换器的波导厚度保持一致。
PCT/CN2022/126677 2021-12-06 2022-10-21 基于SiON起偏器的光纤陀螺用SiN基集成光学芯片 WO2023103610A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202111472069.0A CN113865578B (zh) 2021-12-06 2021-12-06 基于SiON起偏器的光纤陀螺用SiN基集成光学芯片
CN202111472069.0 2021-12-06

Publications (1)

Publication Number Publication Date
WO2023103610A1 true WO2023103610A1 (zh) 2023-06-15

Family

ID=78985822

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/126677 WO2023103610A1 (zh) 2021-12-06 2022-10-21 基于SiON起偏器的光纤陀螺用SiN基集成光学芯片

Country Status (2)

Country Link
CN (1) CN113865578B (zh)
WO (1) WO2023103610A1 (zh)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113865578B (zh) * 2021-12-06 2022-02-08 深圳奥斯诺导航科技有限公司 基于SiON起偏器的光纤陀螺用SiN基集成光学芯片
CN114815051B (zh) * 2022-06-30 2022-09-16 深圳奥斯诺导航科技有限公司 光学陀螺双层SiN基集成驱动芯片

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107561646A (zh) * 2017-10-18 2018-01-09 西安奇芯光电科技有限公司 光波导偏振分离器及其制造方法
US20180259337A1 (en) * 2017-03-09 2018-09-13 Kvh Industries, Inc. Photonic Integrated Circuit For an Interference Fiber Optic Gyroscope (IFOG)
CN109579818A (zh) * 2018-12-12 2019-04-05 天津津航技术物理研究所 一种混合集成光纤陀螺光学芯片的制备方法
US20200371286A1 (en) * 2019-05-22 2020-11-26 Kvh Industries, Inc. Integrated Optical Polarizer and Method of Making Same
US10871614B1 (en) * 2019-07-03 2020-12-22 Globalfoundries Inc. Transverse-electric (TE) pass polarizer
CN112833873A (zh) * 2020-09-12 2021-05-25 天津领芯科技发展有限公司 光子集成芯片以及干涉型光纤陀螺
CN113865578A (zh) * 2021-12-06 2021-12-31 深圳奥斯诺导航科技有限公司 基于SiON起偏器的光纤陀螺用SiN基集成光学芯片

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4220395A (en) * 1974-05-13 1980-09-02 Regents Of University Of California Polarization converter and circuit elements for use in optical waveguides
JP3692474B2 (ja) * 2002-11-01 2005-09-07 日本航空電子工業株式会社 光ファイバジャイロ
CN101216317B (zh) * 2008-01-21 2010-12-01 浙江大学 光纤陀螺用互易性集成光学调制芯片
CN101320113B (zh) * 2008-07-15 2010-06-09 浙江大学 一种波导型偏振模式转换器
CN102565955B (zh) * 2012-01-16 2013-03-20 中国科学院半导体研究所 电可调谐光栅耦合器
CN105444750B (zh) * 2015-11-27 2018-05-22 湖北三江航天红峰控制有限公司 一种保偏光子晶体光纤陀螺及其制造方法
CN109579816B (zh) * 2018-12-12 2020-06-19 天津津航技术物理研究所 混合集成光纤陀螺光学芯片
CN109725385B (zh) * 2019-02-28 2020-05-12 中国电子科技集团公司第二十四研究所 一种基于波导光栅耦合器的光偏振态调整芯片
TWI719888B (zh) * 2020-04-17 2021-02-21 極星光電股份有限公司 積體雙翼式光電感測核心晶片

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180259337A1 (en) * 2017-03-09 2018-09-13 Kvh Industries, Inc. Photonic Integrated Circuit For an Interference Fiber Optic Gyroscope (IFOG)
CN107561646A (zh) * 2017-10-18 2018-01-09 西安奇芯光电科技有限公司 光波导偏振分离器及其制造方法
CN109579818A (zh) * 2018-12-12 2019-04-05 天津津航技术物理研究所 一种混合集成光纤陀螺光学芯片的制备方法
US20200371286A1 (en) * 2019-05-22 2020-11-26 Kvh Industries, Inc. Integrated Optical Polarizer and Method of Making Same
US10871614B1 (en) * 2019-07-03 2020-12-22 Globalfoundries Inc. Transverse-electric (TE) pass polarizer
CN112833873A (zh) * 2020-09-12 2021-05-25 天津领芯科技发展有限公司 光子集成芯片以及干涉型光纤陀螺
CN113865578A (zh) * 2021-12-06 2021-12-31 深圳奥斯诺导航科技有限公司 基于SiON起偏器的光纤陀螺用SiN基集成光学芯片

Also Published As

Publication number Publication date
CN113865578B (zh) 2022-02-08
CN113865578A (zh) 2021-12-31

Similar Documents

Publication Publication Date Title
WO2023103610A1 (zh) 基于SiON起偏器的光纤陀螺用SiN基集成光学芯片
CN101387519B (zh) 一种空芯光子晶体光纤陀螺
WO2024000936A1 (zh) 光学陀螺双层SiN基集成驱动芯片
WO2019067723A1 (en) OPTICAL GYROSCOPE WITH A MULTILAYER WAVEGUIDE
CN112833873A (zh) 光子集成芯片以及干涉型光纤陀螺
CN108225297B (zh) 一种二氧化硅波导与铌酸锂薄膜垂直耦合的谐振式集成光学陀螺
CN114063212B (zh) 一种单片集成的基于薄膜铌酸锂的分束调制芯片
CN109579817B (zh) 一种硅基-ln基混合集成光学芯片的制备方法
CN100367002C (zh) 干涉型硅基芯片微光学陀螺
CN112066973B (zh) 一种铌酸锂波导的集成光子晶体光纤陀螺
Shang et al. Tactical-grade interferometric fiber optic gyroscope based on an integrated optical chip
WO2010118601A1 (zh) 基于表面等离子体激元波导的集成光学光纤陀螺芯片
CN114636413B (zh) 基于绝缘衬底上碳化硅光子集成平台的光学陀螺集成芯片
CN114739376A (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
CN115356867A (zh) 铌酸锂薄膜集成芯片、光电子器件和光纤陀螺
CN114527538A (zh) 一种具有模式选择结构的铌酸锂薄膜芯片
US11656080B1 (en) Silicon nitride waveguide based integrated photonics front-end chip for optical gyroscope
CN111736369A (zh) 一种相位调制器及谐振腔异质集成芯片
CN112097754B (zh) 一种铌酸锂和su-8混合集成空芯光子晶体光纤陀螺
JP6678510B2 (ja) 光導波路素子
CN113884085B (zh) 基于SiO2-SiN耦合芯片结构的光纤陀螺用的集成光学芯片
CN111024058B (zh) 一种基于电光效应开关的实现多次绕行的光纤陀螺仪及其方法
US5625726A (en) Optical waveguide substrate, an article comprising the same and a substrate coupled thereto for holding optical fibers
CN114690453A (zh) 压电-弹光相移器及光学陀螺SiN集成芯片
US6445845B1 (en) Optical switch

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: 22903034

Country of ref document: EP

Kind code of ref document: A1