CN114259203B - Chip integrated coherence tomography system - Google Patents

Abstract

The invention is suitable for the technical field of enhanced optical imaging and provides a chip integrated coherence tomography system. The chip integrated coherence tomography imaging system comprises an imaging component, a silicon substrate and an adjustable delay coil component arranged on the silicon substrate, wherein the imaging component comprises a light source, a first circulator, a first polarization controller and a beam splitter which are sequentially arranged along the light transmission direction; the imaging assembly further comprises a sample arm and a reference arm which are connected with the beam splitter through optical fibers respectively, the sample arm is connected with a sample information acquisition assembly which transmits sample information back to the beam splitter, the adjustable delay coil assembly is connected to the reference arm and is used for carrying out optical path control on input light and transmitting the processed light back to the beam splitter. According to the invention, the large-range adjustment of the imaging depth of the optical coherence tomography can be realized, and the use requirement can be met.

Description

Chip-integrated coherence tomography system

technical field

The invention belongs to the technical field of enhanced optical imaging, in particular to a chip-integrated coherence tomography system.

Background technique

Optical coherence tomography is a high-resolution, non-contact, non-invasive technique for imaging biological tissues. Since it was applied in clinical ophthalmology in the early 1990s, this technology has obtained images similar to ocular histopathological changes in vivo, which has improved the understanding of the occurrence and development of some diseases. After another brand-new diagnostic imaging technology, optical coherence tomography has attracted extensive research due to its high resolution.

In related technologies, the optical path length of the reference arm is increased by adding the length of the optical fiber of the reference arm, so that the optical path difference between the reference arm and the sample arm satisfies the deep imaging of the sample. This method effectively increases the imaging depth, but it can only image at a certain fixed depth or within a small range, and cannot realize a wide range of imaging depth adjustment, and there are still certain defects in use.

Contents of the invention

In view of this, an embodiment of the present invention provides a chip-integrated coherence tomography system to solve the problem that a wide range of imaging depth cannot be adjusted and there are certain defects in use.

In order to solve the above-mentioned problems, the technical solutions of the embodiments of the present invention are implemented in the following way:

A chip-integrated coherence tomography system, comprising an imaging component, a silicon base layer and an adjustable delay coil component arranged on the silicon base layer, the imaging component including a light source and sequentially arranged along the light transmission direction for adjusting the light propagation direction The first circulator, the first polarization controller for controlling the light field mode, and the beam splitter for receiving and splitting the light output from the first polarization controller, the light source, the first circulator The first polarization controller and the beam splitter are all connected by optical fibers; the imaging assembly also includes a sample arm and a reference arm that are respectively connected to the beam splitter by optical fibers, and on the sample arm A sample information collection assembly capable of transmitting sample information back to the beam splitter is connected, the adjustable delay coil assembly is connected to the reference arm, and the adjustable delay coil assembly is used to perform optical processing on the input light process control and send the processed light back to the beam splitter.

In some embodiments, the adjustable delay coil assembly includes a second circulator, a first Mach-Zehnder modulator, a second Mach-Zehnder modulator, a third Mach-Zehnder A modulator and a third circulator, a return optical fiber is connected between the second circulator and the third circulator; wherein, the first Mach-Zehnder modulator and the second Mach-Zehnder modulator between the second Mach-Zehnder modulator and the third Mach-Zehnder modulator, and between the third Mach-Zehnder modulator and the third circulator are connected silicon nitride with different delays Waveguide tunable delay coils.

In some embodiments, the first Mach-Zehnder modulator, the second Mach-Zehnder modulator and the third Mach-Zehnder modulator each include a control electrode for controlling the light propagation path.

In some implementations, the silicon nitride waveguide adjustable delay coil includes a coil body, and an accommodation cavity is formed in the coil body.

In some implementations, the silicon nitride waveguide tunable delay coil further includes a waveguide electrode, and the waveguide electrode is disposed in the accommodating cavity.

In some embodiments, the waveguide electrode is covered with a layer of nonlinear dielectric material.

In some embodiments, the imaging component further includes a reflector for receiving the light emitted by the third circulator and reflecting the light back to the third circulator, the reflector and the third circulator The devices are connected by optical fiber.

In some implementations, a second polarization controller for controlling the light field mode of the light is further arranged on the optical fiber between the beam splitter and the second circulator.

In some embodiments, the sample information collection component includes a third polarization controller arranged in sequence along the light propagation direction and connected by an optical fiber, an optical fiber delay coil for adjusting the optical path matching degree on the sample arm, and an optical fiber delay coil for collecting An adjustable focus lens group for sample information, the adjustable focus lens group is set opposite to the sample to be measured.

In some embodiments, the imaging component further includes a receiver for receiving information returned from the beam splitter and containing sample information, and the receiver is connected to the first circulator through an optical fiber.

A chip-integrated coherence tomography system provided by an embodiment of the present invention includes an imaging component, a silicon base layer, and an adjustable delay coil component disposed on the silicon base layer, and the adjustable delay coil component is used to control the optical path of the input light , and transmit the processed light back to the beam splitter. In this way, by setting the adjustable delay coil assembly and controlling the working mode of the adjustable delay coil assembly, the precise control of the length of the optical path can be realized, so that the length of the reference arm in the detection process can be adjusted as required, Moreover, the adjustment range is wide, the adjustment precision is high, and the imaging depth of the optical coherence tomography can be adjusted in a large range. Moreover, the chip-integrated coherence tomography system is small in size, compact in structure, easy to produce, and meets usage requirements.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the accompanying drawings that need to be used in the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For Those skilled in the art can also obtain other drawings based on these drawings without any creative effort.

FIG. 1 is a schematic structural diagram of a chip-integrated coherence tomography system provided by an embodiment of the present invention;

Fig. 2 is a schematic structural diagram of a silicon-based layer provided by an embodiment of the present invention;

Fig. 3 is a schematic structural diagram of a silicon nitride waveguide tunable delay coil provided by an embodiment of the present invention.

Explanation of reference signs:

1. Chip integrated coherence tomography system; 10. Sample; 11. Silicon base layer; 111. Silicon substrate; 112. Silicon dioxide buried oxide layer; 113. Silicon nitride layer; 12. Imaging component; 121. Light source; 122 , the first circulator; 123, the first polarization controller; 124, the beam splitter; 125, the sample arm; 126, the reference arm; 13, the sample information collection component; 131, the third polarization controller; 132, the fiber delay coil ; 133, adjustable focal length lens group; 14, adjustable delay coil assembly; 140, control electrode; 141, second circulator; 142, first Mach-Zehnder modulator; 143, second Mach-Zehnder modulator; 144 , third Mach-Zehnder modulation; 145, third circulator; 146, return optical fiber; 147, silicon nitride waveguide adjustable delay coil; 1471, coil body; 1472, containing cavity; 1473, waveguide electrode; 1474, non A linear dielectric material layer; 15, a reflector; 16, a second polarization controller; 17, a receiver.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

The various specific technical features described in the specific embodiments can be combined in any suitable manner if there is no contradiction, for example, different embodiments and technical solutions can be formed by combining different specific technical features. In order to avoid unnecessary repetition, various possible combinations of specific technical features in the present invention will not be further described.

It should also be noted that the orientation terms such as left, right, up, and down in the embodiments of the present invention are only relative concepts or refer to the normal use state of the product, and should not be regarded as restrictive .

As shown in FIGS. 1 and 2 , a chip-integrated coherence tomography system 1 provided by an embodiment of the present invention includes an imaging component 12 , a silicon base layer 11 and an adjustable delay coil component 14 disposed on the silicon base layer 11 . The silicon base layer 11 includes a silicon substrate 111 at the bottom layer, a silicon dioxide buried oxide layer 112 at the middle layer, and a silicon nitride waveguide layer 113 at the top layer. The imaging component 12 includes a light source 121, a first circulator 122 for regulating the direction of light propagation, a first polarization controller 123 for controlling the light field mode, and a first polarization controller 123 for receiving light from the first polarization controller. 123 output light and beam splitter 124 for splitting light, the light source 121, the first circulator 122, the first polarization controller 123 and the beam splitter 124 are all connected by optical fibers; A sample arm 125 and a reference arm 126 connected to the beam splitter 124, the sample arm 125 is connected with a sample information collection assembly 13 capable of returning sample information to the beam splitter 124, and the adjustable delay coil assembly 14 is connected to the reference arm 126, The adjustable delay coil assembly 14 is used to control the optical path of the input light, and return the processed light to the beam splitter 124 . Specifically, the light source 121 provides a signal of the light source 121 for the system, and the specific wavelength of the light source 121 can be changed according to different samples. The light emitted by the light source 121 is transmitted to the first circulator 122 through the optical fiber, and the light can only travel in one direction in the first circulator 122, and the light enters the first polarization controller 123 after being emitted from the first circulator 122 , the input light is kept in the TE mode through the first polarization control, and after entering the beam splitter 124, the beam splitter 124 can be selected as a wide-spectrum optical fiber beam splitter 124, which can split the light into beams with the same frequency and phase . The light intensity of the light beam is divided into 3:1 by the beam splitter 124 and enters the sample arm 125 and the reference arm 126 respectively. The sample information collection component 13 is arranged on the sample arm 125 . The sample information collection component 13 can collect sample phase information in a relatively large depth range. And after collecting the phase information of the sample, it returns to the beam splitter 124 along the optical path. The adjustable delay coil assembly 14 provided on the reference arm 126 can realize a wide range and precise control of the optical path of the light according to the detection requirements, and transmit the regulated light back to the beam splitter 124 . In this way, the light returned from the sample information collection assembly 13 and the light returned from the adjustable delay coil assembly 14 interfere in the beam splitter 124, and the interference information passes through the first circulator 122 and is output to the receiver 17, and finally processed by calculation unit to form an image.

The chip-integrated coherence tomography system 1 provided by the embodiment of the present invention can precisely control the length of the optical path by controlling the working mode of the adjustable delay coil assembly 14, so that the reference arm 126 in the detection process The length can be adjusted as required, and the adjustment range is wide, the adjustment precision is high, and the imaging depth of the optical coherence tomography can be adjusted in a wide range. Moreover, the chip-integrated coherence tomography system 1 is small in size, compact in structure, easy to produce, and meets usage requirements.

As shown in FIG. 2, in some embodiments, the thickness of the silicon substrate 111 is optionally set to 600 μm, the thickness of the silicon dioxide buried oxide layer 112 is set to 2-3 μm, and the silicon nitride waveguide on the top layer The thickness of the layer 113 is set to be 0.3-1 μm, so as to reliably meet the configuration requirements of the entire system structure.

As shown in Fig. 1, in some embodiments, the adjustable delay coil assembly 14 includes a second circulator 141, a first Mach-Zehnder modulator 142, a second Mach-Zehnder modulator 142, a second Mach-Zehnder modulator 142, The Del modulator 143 , the third Mach-Zehnder modulator 144 and the third circulator 145 , and the return optical fiber 146 is connected between the second circulator 141 and the third circulator 145 . And, between the first Mach-Zehnder modulator 142 and the second Mach-Zehnder modulator 143, between the second Mach-Zehnder modulator 143 and the third Mach-Zehnder modulator 144, and between the third Mach-Zehnder modulator Silicon nitride waveguide adjustable delay coils 147 with different delays are connected between 144 and the third circulator 145 . Specifically, the arrangement of the second circulator 141 and the third circulator 145 can control the propagation direction of the light, so as to prevent the light emitted from the third circulator 145 from entering the silicon nitride waveguide again after being converted into reflected light. Adjust the delay coil 147. The silicon nitride waveguide adjustable delay coil 147 is a waveguide coil designed by a silicon nitride waveguide with a periodic structure. As the length of the waveguide increases, the distance of light propagation in the waveguide will also increase, thereby increasing the optical path. In this way, the fixed increase of the optical path can be controlled by adjusting the number of connected coils. The settings of the first Mach-Zehnder modulator 142, the second Mach-Zehnder modulator 143, and the third Mach-Zehnder modulator 144 are respectively used to control the access of silicon waveguide adjustable delay coils connected at corresponding positions. Condition. Through this structural arrangement, the light emitted from the second circulator 141 goes to the first Mach-Zehnder modulator 142, the second Mach-Zehnder modulator 143, the third Mach-Zehnder modulator 144 and the third circulator 145. According to the requirements of use, the length of the optical path can be controlled through the corresponding control of the three Mach-Zehnder modulators. That is, when the first Mach-Zehnder modulator 142 is turned on, the light will travel to the adjustable silicon nitride waveguide arranged between the first Mach-Zehnder modulator 142 and the second Mach-Zehnder modulator 143. The delay coil 147, and after passing through the silicon nitride waveguide adjustable delay coil 147, transmits according to whether the second Mach-Zehnder modulator 143 is turned on or off. When the second Mach-Zehnder modulator 143 is in the off state, the light will be transmitted directly to the third Mach-Zehnder modulator 144; and when the second Mach-Zehnder modulator 143 is in the open state, the light will be transmitted The direction is arranged in the silicon nitride waveguide adjustable delay coil 147 located between the second Mach-Zehnder modulator 143 and the third Mach-Zehnder modulator 144 , and finally transmitted to the third Mach-Zehnder modulator 144 . At this time, the transmission is performed according to whether the third Mach-Zehnder modulator 144 is turned on or off. When the third Mach-Zehnder modulator 144 is in the off state, the light will be directed to the third circulator 145; and when the third Mach-Zehnder modulator 144 is in the open state, the light will be directed to the set In the silicon nitride waveguide tunable delay coil 147 located between the third Mach-Zehnder modulator 144 and the third circulator 145 , it is finally transmitted to the third circulator 145 . In this way, by controlling the number of silicon nitride waveguide adjustable delay coils 147 that the light passes through, the control of the entire optical path is realized, and the purpose of controlling the total length of the optical path is achieved.

In some embodiments, the number of Mach-Zehnder modulators and the number of silicon nitride waveguide adjustable delay coils 147 arranged between two adjacent Mach-Zehnder modulators can be selected according to different design requirements. , there is no restriction here. Moreover, when there are more than two silicon nitride waveguide adjustable delay coils 147 arranged between two Mach-Zehnder modulators, each silicon nitride waveguide adjustable delay coil 147 is arranged in series.

As shown in FIG. 1 , in the embodiment of the invention, according to design requirements, the waveguide lengths of the silicon nitride waveguide adjustable delay coils 147 are all the same as ΔL, located between the first Mach-Zehnder modulator 142 and the second Mach-Zehnder modulator 142. The silicon nitride waveguide adjustable delay coil 147 between the Del modulators 143 is set as one, the silicon nitride waveguide adjustable delay coil 147 between the second Mach-Zehnder modulator 143 and the third Mach-Zehnder modulator 144 There are two, and there are four silicon nitride waveguide adjustable delay coils 147 located between the third Mach-Zehnder modulator 144 and the third circulator 145 . In this way, the system can realize the control of the delay amount from 0 to 7ΔL. Of course, the length of ΔL can be modified technically according to specific applications, and the number of settings can also be adjusted, so as to obtain different optical paths, realize a wide range of delays in optical paths, and meet different application requirements.

As shown in FIG. 1, in some embodiments, the first Mach-Zehnder modulator 142, the second Mach-Zehnder modulator 143, and the third Mach-Zehnder modulator 144 each include a control electrode for controlling the light propagation path. 140. Whether the silicon nitride waveguide adjustable delay coil 147 is connected to the optical path is controlled by the voltage applied on the control electrode 140, thereby changing the number of connected silicon nitride waveguide adjustable delay coils 147 to achieve the control of the total length of the optical path. Purpose.

As shown in FIG. 1 and FIG. 3 , in some embodiments, the silicon nitride waveguide tunable delay coil 147 includes a coil body 1471 , and a receiving cavity 1472 is formed in the coil body 1471 . Specifically, the coil body 1471 is a waveguide coil designed by a silicon nitride waveguide in a periodic structure. As the length of the waveguide increases, the distance traveled by light in the waveguide also increases. In this way, the coil body 1471 is wound into a required shape according to the design requirement, so as to increase the length of the optical path. In the embodiment of the present invention, an accommodating cavity 1472 is formed in the middle position of the coil body 1471 through winding.

As shown in FIG. 3 , in some embodiments, the silicon nitride waveguide tunable delay coil 147 further includes a waveguide electrode 1473 , and the waveguide electrode 1473 is disposed in the cavity 1472 . The configuration of the waveguide electrode 1473 is used to apply an electric field to both ends of the waveguide to change the effective refractive index of the waveguide, thereby changing the optical path. In this way, by controlling the optical path in a single silicon nitride waveguide adjustable delay coil 147, it is also possible to achieve fine adjustment of the optical path length within a certain range, which improves the adjustment range and adjustment efficiency of the entire optical path length control. precision.

As shown in FIG. 3 , in some embodiments, the waveguide electrode 1473 is covered with a nonlinear dielectric material layer 1474 . The nonlinear dielectric material layer 1474 is used to enhance the Kerr effect of the waveguide, making the electrical modulation effect more obvious. In this way, after the waveguide electrode 1473 on each silicon nitride waveguide adjustable delay coil 147 is energized, the effective refractive index of the waveguide will change due to the action of the electric field and the nonlinear dielectric material, thereby realizing the change in a small range Optical path. Of course, the silicon nitride waveguide layer 113 may also be covered with a nonlinear dielectric material layer 1474 to improve performance. Specifically, the nonlinear dielectric material can be prepared on the waveguide of the silicon nitride waveguide adjustable delay coil 147 by wet transfer or physical vapor deposition to improve the electrical modulation effect. The nonlinear dielectric material may be graphene, transition metal sulfides (such as two-dimensional materials such as molybdenum disulfide and tungsten disulfide), etc.

As shown in FIG. 1 , in some embodiments, the imaging component 12 further includes a reflector 15 for receiving the light emitted by the third circulator 145 and reflecting the light back to the third circulator 145, the reflector 15 and the first circulator 145 The three circulators 145 are connected through optical fibers. In this way, the light emitted from the third circulator 145 goes to the emitter, and the reflector 15 re-enters the reflected light into the third circulator 145 along the optical path. Both the second circulator 141 and the third circulator 145 can control the incoming light and the reflected re-entering light from interfering with each other. In this way, the reflected light entering the third circulator 145 enters the return optical fiber 146 through the output port, enters the second circulator 141 , and finally enters the beam splitter 124 .

As shown in FIG. 1 , in some embodiments, a second polarization controller 16 for controlling the light field mode is also provided on the optical fiber between the beam splitter 124 and the second circulator 141 . By setting the second polarization control, it is ensured that the reflected light is still in the TE mode, and the accuracy of the result is improved. The TE mode refers to a propagation mode in which the longitudinal component of the electric field is zero and the longitudinal component of the magnetic field is not zero in the propagation direction of the electromagnetic wave.

As shown in FIG. 1 , in some embodiments, the sample information acquisition assembly 13 includes a third polarization controller 131 connected by an optical fiber, an optical fiber delay coil 132 for adjusting the optical path matching degree on the sample arm 125 and an optical fiber delay coil 132 for collecting sample information. adjustable focus lens group 133, and the adjustable focus lens group 133 is spaced opposite to the sample 10 to be tested. In this way, the setting of the third polarization controller 131 ensures that the incident light and the reflected light are in the TE mode. The optical fiber delay coil 132 is a fixed-length coil made of optical fiber, and the optical path of the reference arm 126 and the sample arm 125 can be matched by the length of the fixedly connected optical fiber delay coil 132 . Specifically, the adjustable focus lens group 133 focuses the light to illuminate the sample 10, the light is reflected and scattered at the sample 10, and this part of the signal light is received by the focus adjustable lens group and returns to the beam splitter 124 along the optical path. The required number of adjustable delay coils 147 can be connected according to the optical path difference required by the adjustable focal length lens group 133 , so that the optical path difference between the sample arm 125 and the reference arm 126 is in a proper size. Then, by connecting the waveguide electrode 1473 on the silicon nitride waveguide adjustable delay coil 147 and applying different voltages, the imaging image can be tuned in the deeper or shallower range at the observation depth.

As shown in FIG. 1 , in some embodiments, the imaging component 12 further includes a receiver 17 for receiving the sample information returned from the beam splitter 124 , and the receiver 17 is connected to the first circulator 122 through an optical fiber. The receiver 17 forms an image through the calculation and processing unit of the received light containing the sample detection information, and finally outputs the sample information after processing to complete the detection.

The chip-integrated coherence tomography system 1 provided in the embodiment of the present invention can adjust the number of adjustable delay coils 147 connected to the silicon nitride waveguide so that the overall optical path change can be adjusted in a wide range. Applying a voltage to the waveguide electrode 1473 on the top makes the overall optical path adjustable within a certain range, thus achieving a wide range and fine adjustment function. The chip-integrated coherence tomography system 1 utilizes the characteristics of low transmission loss and wide transparent window of silicon nitride, so that the loss of light in the silicon nitride waveguide adjustable delay coil 147 is very low, thereby making the chip-integrated coherence tomography The overall power consumption of the system 1 is reduced, and the system can be adapted to most light sources 121 on the market due to the transparent window of silicon nitride of 0.4-8 μm. At the same time, the chip-integrated coherence tomography system 1 is integrated on a silicon base, has the advantages of small size and compact structure, is easy to mass-produce in actual production, and has good economic benefits.

The working mode of the chip-integrated coherence tomography system 1 provided in the embodiment of the present invention is as follows:

The coherent light emitted by the light source 121 passes through the first circulator 122 so that the light enters the first polarization controller 123, and the first polarization controller 123 controls the input light to be a TE mode, and then enters the beam splitter 124 to split the light into two beams, The beam splitting ratio is that the light intensity of the sample arm 125 is 3:1 to the light intensity of the reference arm 126 , and this ratio can be changed according to different samples 10 to be tested. The light in the sample arm 125 passes through the third polarization controller 131 to ensure that the light is still in the TE mode, and then the light enters the focal length adjustable lens group after passing through the fiber delay coil 132, and the focal length adjustable lens group focuses the light and irradiates the sample 10, The light is reflected and scattered at the sample 10 , and this part of the signal light is received by the focal length adjustable lens group, and returns to the beam splitter 124 along the optical path. The light in the reference arm 126 exits the beam splitter 124 and passes through the second polarization controller 16 to the second circulator 141, after which the light can change the first Mach-Zehnder modulator 142 when passing through the first Mach-Zehnder modulator 142 The voltage above controls whether the light passes through the silicon nitride waveguide adjustable delay coil 147, and when the three Mach-Zehnder modulators control the light path not to pass through the silicon nitride waveguide adjustable delay coil 147, the delay amount is zero. When light passes through the silicon nitride waveguide tunable delay coil 147, it can be realized by adjusting the voltage of the control electrode 140 on the first Mach-Zehnder modulator 142, the second Mach-Zehnder modulator 143 and the third Mach-Zehnder modulator 144. For optical path switching, if the increased optical path of each silicon nitride waveguide tunable delay coil 147 is ΔL, the system can achieve a delay of 0 to 7ΔL. In addition, after each silicon nitride waveguide adjustable delay coil 147 is powered on, the effective refractive index of the waveguide will change due to the action of the electric field and the nonlinear dielectric material, thereby changing the optical path within a small range. The light enters the third circulator 145 after passing through the last silicon nitride waveguide adjustable delay coil 147, and reaches the reflector 15 along the optical path, and the reflected light enters the third ring circulator 145 again along the optical path, and reaches the third circulator through the output port. The second circulator 141 returns to the second polarization controller 16 and the beam splitter 124 along the optical path. The second polarization controller 16 ensures that the reflected light is still in TE mode. The reference light and the sample light interfere in the beam splitter 124, and the interference information enters the receiver through the first circulator 122, and after the image is formed by the computing and processing unit, the sample information is processed and output.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

Claims (9)

1. A chip-integrated coherence tomography system, characterized in that it comprises an imaging assembly, a silicon base layer and an adjustable delay coil assembly disposed on the silicon base layer, the silicon base layer includes a silicon substrate at the bottom, a middle layer The silicon dioxide buried oxide layer and the silicon nitride waveguide layer on the top layer, the imaging component includes a light source and a first circulator arranged in sequence along the light transmission direction for adjusting the light propagation direction, and for controlling the light field mode a first polarization controller and a beam splitter for receiving and splitting light output from the first polarization controller, the light source, the first circulator, the first polarization controller and the The beam splitters are all connected by optical fibers; the imaging assembly also includes a sample arm and a reference arm which are respectively connected to the beam splitter by optical fibers. The sample information acquisition assembly of the detector, the adjustable delay coil assembly is connected to the reference arm, the adjustable delay coil assembly is used to control the optical path of the input light, and transmit the processed light back to the splitter Beamer; the adjustable delay coil assembly includes a second circulator, a first Mach-Zehnder modulator, a second Mach-Zehnder modulator, a third Mach-Zehnder modulator, which are sequentially arranged along the light propagation direction and connected in series through an optical fiber and the third circulator, the return optical fiber is connected between the second circulator and the third circulator, and between the first Mach-Zehnder modulator and the second Mach-Zehnder modulator, the second Mach-Zehnder modulator Silicon nitride waveguide adjustable delay coils with different delays are connected between the third Mach-Zehnder modulator and between the third Mach-Zehnder modulator and the third circulator, and the silicon nitride waveguide adjustable delay coil is composed of The silicon nitride waveguide is designed according to a periodic structure, and the waveguide lengths of each silicon nitride waveguide adjustable delay coil are the same. 2. The chip integrated coherence tomography system according to claim 1, wherein the first Mach-Zehnder modulator, the second Mach-Zehnder modulator and the third Mach-Zehnder modulator are all Contains control electrodes for controlling the light propagation path. 3 . The chip integrated coherence tomography system according to claim 2 , wherein the silicon nitride waveguide adjustable delay coil comprises a coil body, and an accommodation cavity is formed in the coil body. 4 . 4 . The chip-integrated coherence tomography system according to claim 3 , wherein the silicon nitride waveguide adjustable delay coil further comprises a waveguide electrode, and the waveguide electrode is arranged in the accommodating cavity. 5. The chip-integrated coherence tomography system according to claim 4, characterized in that, the waveguide electrode is covered with a layer of nonlinear dielectric material. 6. The chip-integrated coherence tomography system according to any one of claims 1 to 5, characterized in that, the imaging component further includes a device for receiving the light emitted by the third circulator and reflecting the light back to the reflector of the third circulator, and the reflector and the third circulator are connected by an optical fiber. 7. The chip-integrated coherence tomography system according to any one of claims 1 to 5, characterized in that, an optical fiber for controlling light is also provided on the optical fiber between the beam splitter and the second circulator. Field mode second polarization controller. 8. The chip-integrated coherence tomography system according to any one of claims 1 to 5, wherein the sample information collection component includes a third polarization controller arranged in sequence along the light propagation direction and connected by an optical fiber , an optical fiber delay coil for adjusting the optical path matching degree on the sample arm and an adjustable focus lens group for collecting sample information, the adjustable focus lens group is arranged opposite to the sample to be measured. 9. The chip-integrated coherence tomography system according to any one of claims 1 to 5, characterized in that, the imaging component further includes a receiver for receiving information returned from the beam splitter and containing sample information. The receiver is connected to the first circulator through an optical fiber.

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