Near-infrared cascade super lens for endoscopic imaging

Abstract

The utility model discloses a near-infrared cascading super lens for endoscopic imaging. The near-infrared cascading super lens comprises a silicon dioxide substrate layer and a double-layer nano-column structure made of silicon materials. Through the precise arrangement design of the nanorods, the lens achieves efficient optical modulation in the near-infrared band, has the high-resolution and large-view-field imaging capacity, and is suitable for a miniaturized endoscopic system. According to the structure, the imaging depth and resolution are remarkably improved, the problems of size and structure complexity of a traditional optical lens are solved, and a better solution is provided for medical endoscopic imaging.

Description

Technical Field

[0001] This utility model relates to a near-infrared cascaded superlens, and more particularly to a near-infrared cascaded superlens for endoscopic imaging of the ear, nose and throat and a corresponding endoscopic imaging system. Background Technology

[0002] With the rapid development of medical imaging technology, improving the resolution and imaging depth of ENT endoscopy has become a key research focus. Near-infrared light, due to its excellent tissue penetration and low scattering characteristics, is increasingly being used in endoscopic imaging systems. However, existing endoscopic imaging devices typically rely on traditional optical lenses. While these lenses can focus near-infrared light for imaging, their large size and complex structure make them difficult to integrate into miniaturized endoscopic devices, and they also have limitations in terms of depth resolution. To overcome these shortcomings, superlens technology has gradually attracted attention in recent years. A superlens is a planar lens based on subwavelength nanostructures that enables efficient light wave manipulation. It is not only small and easy to integrate, but also, through precise design, can achieve high-resolution imaging with a wide field of view. Utility Model Content

[0003] To address the aforementioned technical problems, the inventors of this invention propose a near-infrared cascaded superlens for endoscopic imaging in the ear, nose, and throat, thereby solving the issues of insufficient imaging resolution and limited field of view in existing endoscopic systems. This design replaces traditional optical lenses with near-infrared cascaded superlenses, achieving more efficient optical imaging and miniaturization of the device within the endoscopic system. The technical solution proposed in this invention employs a cascaded design of near-infrared superlenses. By precisely controlling the arrangement of nanostructures, the field of view of the superlens is significantly improved, while simultaneously optimizing light focusing ability and scattering control. This allows the imaging system to adapt to different tissue morphologies, thus providing more accurate and in-depth information output.

[0004] This invention provides a near-infrared cascaded superlens for endoscopic imaging, characterized in that it comprises: a substrate layer; a first nanopillar layer located on the upper side of the substrate layer; and a second nanopillar layer located on the lower side of the substrate layer.

[0005] Preferably, the height of the first nanopillar layer is 840 nm, the periodic arrangement of the nanopillars is a square lattice, that is, the center points of the nanopillars are arranged in a square shape, the nanopillars are arranged at the vertices of the square, the distance between adjacent nanopillars is equal and is 720 nm, the material is silicon, and the radius of the first nanopillar layer is 95 micrometers.

[0006] Preferably, the height of the second nanopillar layer is 820 nm, the periodic arrangement of the nanopillars is a square lattice, that is, the center points of the nanopillars are arranged in a square shape, the nanopillars are arranged at the vertices of the square, the distance between adjacent nanopillars is equal and is 720 nm, the material is silicon, and the radius of the second nanopillar layer is 165 micrometers.

[0007] Preferably, the substrate is cylindrical with a radius of 200 micrometers and is made of silicon dioxide.

[0008] Preferably, the working wavelength of the superlens is 1410 nm.

[0009] This invention provides a cascaded superlens in the near-infrared band. By designing the arrangement of nanopillars and optimizing the phase distribution using Zemax, a large field-of-view metasurface design is achieved. Through careful arrangement, the near-infrared cascaded superlens design is realized. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of this utility model, the accompanying drawings required in the description of the embodiments are now briefly introduced. Obviously, the drawings described below are only some embodiments of this application. Those skilled in the art can still obtain other drawings based on these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of the overall structure of the near-infrared cascaded superlens according to an embodiment of the present invention;

[0012] Figure 2 This is a ray tracing diagram of the cascaded metasurface imaging system according to an embodiment of the present invention;

[0013] Figure 3 This is a schematic diagram of the metasurface nanopillar structure according to an embodiment of the present invention;

[0014] Figure 4 This is a three-dimensional schematic diagram of a near-infrared superlens according to an embodiment of the present invention;

[0015] Figure 5 The following is a modulation transfer function diagram of a finite conjugate optical imaging system according to an embodiment of the present invention; the numbers in the diagram are as follows: 1-first nanopillar layer, 2-base layer, 3-second nanopillar layer, 4-fiber image bundle end face. Detailed Implementation

[0016] To better understand the above-mentioned objectives, features, and advantages of this utility model, it will now be described in further detail with reference to the accompanying drawings and specific embodiments. It should be noted that, without conflict, the embodiments and features of this application can be combined with each other.

[0017] In the following description, numerous specific details are set forth to aid in a better understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein, and therefore its scope of protection is not limited to the specific embodiments disclosed below.

[0018] In the actual design, the parameters of the finite conjugate optical imaging system based on cascaded metasurfaces are set as follows: object distance is 200 μm, numerical aperture of object space is 0.4, and full field of view diameter is 200 μm; the aperture stop is located on the front surface of the first nanopillar layer.

[0019] Figure 1 The following is a schematic diagram of the overall structure of a near-infrared cascaded superlens for endoscopic imaging. The cascaded superlens consists of a first nanopillar layer, a substrate layer, and a second nanopillar layer. The optical amplitude and phase of the target object are modulated sequentially through the first nanopillar layer, the substrate layer, and the second nanopillar layer, and finally imaged at the end face of the fiber optic image bundle.

[0020] Figure 2 This is a ray tracing diagram of the cascaded metasurface imaging system implemented in this experiment. The first nanopillar layer is placed in front of the object surface to perform preliminary optical amplitude and phase modulation of the incident light. The base layer is used to connect the first and second nanopillar layers and provide support for light propagation. The second nanopillar layer further modulates the light, so that the optical signal formed after passing through the two metasurface layers is focused and imaged on the image surface. This design ensures that the system can achieve high-resolution imaging over extremely short distances.

[0021] In the specific implementation process, such as Figure 3 The nanopillars of the first and second nanopillar layers shown are made of silicon with a refractive index of 3.48, and the substrate layer is made of silicon dioxide with a refractive index of 1.44.

[0022] The first nanopillar layer has a cylindrical shape for its nanopillar structural units, and the second nanopillar layer also has a cylindrical shape for its nanopillar structural units.

[0023] Among them, such as Figure 4 As shown, the periodic arrangement of the nanopillar unit structures in the first and second nanopillar layers is a square lattice, that is, the center points of the nanopillars are arranged in the shape of a square, the nanopillars are arranged at the vertices of the square, and the distance between adjacent nanopillars is equal, which is 720nm.

[0024] The periodic lattice constant and columnar structure height of the first nanopillar layer were selected as 720 nm and 840 nm, respectively; the periodic lattice constant and columnar structure height of the second nanopillar layer were 720 nm and 820 nm, respectively. Based on the phase modulation corresponding to each columnar structure, a set of columnar unit structures with high transmission efficiency was obtained, while ensuring that the phase modulation range could cover 0 to 2π.

[0025] Figure 5 The modulation transfer function (MTF) curves of a finite conjugate optical imaging system are used to characterize the contrast transfer capability of the system at different spatial frequencies. Field of view 1 is 0°, field of view 2 is 21°, and field of view 3 is 42°.

[0026] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating this utility model, and are not intended to limit the implementation of this utility model. Those skilled in the art can make other adjustments, changes, or modifications based on the above description. Because the technical solution of this utility model is quite flexible, different design optimizations or improvements may occur in specific applications, and these changes need not and cannot be fully listed here.

Claims

1. A near-infrared cascaded superlens for endoscopic imaging, characterized in that, include: basal layer; The first nanopillar layer is located on the upper side of the substrate. The nanopillars in the first nanopillar layer have a height of 840 nm and are arranged in a square lattice pattern, meaning that the center points of the nanopillars are arranged in a square shape. The distance between adjacent nanopillars is equal and is 720 nm. The material is silicon. The second nanopillar layer is located on the lower side of the substrate. The nanopillars in the second nanopillar layer have a height of 820 nm and are arranged in a square lattice pattern. The distance between adjacent nanopillars is equal and is 720 nm. The material is silicon.

2. The near-infrared cascaded superlens according to claim 1, characterized in that, The base layer is cylindrical with a radius of 200 micrometers and is made of silicon dioxide.

3. The near-infrared cascaded superlens according to claim 1, characterized in that, The working wavelength of the superlens is 1410 nm.

4. The near-infrared cascaded superlens according to claim 1, characterized in that, The radius of the first nanopillar layer is 95 micrometers.

5. The near-infrared cascaded superlens according to claim 1, characterized in that, The radius of the second nanopillar layer is 165 micrometers.

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