Endoscope illumination device and method thereof

Abstract

An endoscope illumination device and a method thereof. The endoscope illumination device comprises a light source assembly, an optical cable assembly, and a planar optical element. The light source assembly is configured to emit illumination light. The optical cable assembly has an incident end and an emission end, and the incident end of the optical cable assembly corresponds to the light source assembly, configured to transmit the illumination light emitted by the light source assembly from the incident end to the emission end. The planar optical element is correspondingly arranged at the emission end of the optical cable assembly, and the planar optical element comprises a substrate layer and at least one super-structured surface layer, wherein the at least one super-structured surface layer is formed on the substrate layer in a superposed manner, and each super-structured surface layer is composed of an arrangement of micro-nano antennas in a sub-wavelength scale, configured to regulate the illumination light emitted from the emission end of the optical cable assembly to achieve a uniform illumination effect in a large field of view.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of endoscopes, and in particular to an endoscope illumination device and method thereof. BACKGROUND

[0002] An endoscope refers to a detection device containing an image sensor, an optical lens, an illumination structure, and a mechanical device, which can be inserted into the digestive tract or other pipelines to observe the internal environment and transmit images, so as to enable doctors or professionals to make diagnoses. The image quality of a medical endoscope is required to be very high, because a clear image can enable doctors and professionals to make more accurate judgments and operations on patients. When observing a cavity or tissue in the body by using an endoscope, sufficient external light radiation energy needs to be introduced into the body, otherwise it will be difficult to clearly image, thereby causing trouble for doctors and professionals in diagnosis, so most endoscopes usually use an optical cable composed of multiple optical fibers to transmit light radiation energy to provide illumination light. In addition, in order to improve the imaging effect, the illumination light provided by the endoscope needs to form a uniform lighting effect in the illumination area, and in the case of large field angle illumination, sufficient illuminance also needs to be ensured.

[0003] As shown in Figure 1 , a conventional endoscope system usually includes an illumination light source 1P, a collimating coupling assembly 2P, and an optical cable 3P, so that the illumination light emitted by the illumination light source 1P is coupled into the optical cable 3P through the collimating coupling assembly 2P, and then transmitted to the end of the optical cable 3P by total reflection in the optical cable 3P to illuminate the illumination area (such as human tissue or structure) to be observed. At the same time, in order to meet the requirements of uniform illumination of the illumination area and large field angle, a uniform light illumination system 4P needs to be arranged at the end of the optical cable 3P, and how to design the uniform light illumination system 4P at the end of the optical cable 3P is very crucial.

[0004] At present, as shown in Figure 2 , the existing uniform light illumination system 4P usually arranges a lens group 41P composed of multiple optical lenses at the end of the optical cable 3P, so that the illumination light rays emitted from the end of the optical cable 3P are converged and then diverged by the lens group 41P, so as to achieve the effect of uniform light while also expanding the divergence angle of the illumination light to expand the lighting range.

[0005] However, the existing light uniformity illumination system 4P arranged at the end of the optical cable 3P has many problems: on the one hand, the assembly of multiple optical lenses is difficult, not only because the size of the optical lens is small and the surface is curved, so it is difficult to ensure high coaxiality during assembly, but also because the center of the optical lens is difficult to align with the center of the optical cable 3P, so there is an assembly deviation to cause poor light uniformity effect; on the other hand, since the endoscope often needs to be subjected to high-temperature disinfection treatment before use, the cooperation between the optical lenses in the existing light uniformity illumination system 4P is prone to dislocation, causing the structure of the lens group 41P to be unstable, and greatly reducing the stability of the illumination system. In addition, since the existing light uniformity illumination system 4P includes multiple optical lenses and is arranged at the head of the endoscope, the weight and volume of the head of the endoscope are relatively large, which will greatly inconvenience the operation of the endoscope. SUMMARY

[0006] An advantage of the present application is to provide an endoscope illumination device and method thereof, which can perform light uniformity processing on the illumination light while also being able to control the angle of the illumination light to achieve a light uniformity effect in a large field of view.

[0007] Another advantage of the present application is to provide an endoscope illumination device and method thereof, wherein in an embodiment of the present application, the endoscope illumination device can reduce the assembly difficulty of the endoscope, reduce the size of the head of the endoscope, and help meet the design requirements of miniaturization and integration of the head of the endoscope.

[0008] Another advantage of the present application is to provide an endoscope illumination device and method thereof, wherein in an embodiment of the present application, the endoscope illumination device can reduce the difficulty of the assembly process, and help increase the stability of the structure and the stability of the optical properties.

[0009] Another advantage of the present application is to provide an endoscope illumination device and method thereof, wherein in an embodiment of the present application, the endoscope illumination device can greatly reduce the weight and size of the head of the endoscope, facilitate precise operation of the endoscope, and reduce patient pain.

[0010] Another advantage of the present application is to provide an endoscope illumination device and method thereof, wherein in an embodiment of the present application, the endoscope illumination device can use a metasurface structure to control the angle distribution and illumination distribution of the illumination light, so as to provide more dimensional parameters and high flexibility in design.

[0011] Another advantage of the present application is to provide an endoscope illumination device and a method thereof, wherein in an embodiment of the present application, the endoscope illumination device is capable of achieving wide field of view and uniform illumination within a range of arbitrary angles, which helps to provide better quality endoscopic images for doctors and professionals to make more accurate judgments and operations on patients.

[0012] Another advantage of the present application is to provide an endoscope illumination device and a method thereof, wherein in order to achieve the above-mentioned purpose, in the present application, expensive materials or complex structures are not required. Therefore, the present application successfully and effectively provides a solution, which not only provides a simple endoscope illumination device and a method thereof, but also increases the practicability and reliability of the endoscope illumination device and the method thereof.

[0013] In order to achieve at least one advantage or other advantages or purposes mentioned above, the present application provides an endoscope illumination device, comprising:

[0014] a light source assembly, wherein the light source assembly is used for emitting illumination light;

[0015] a light cable assembly, wherein the light cable assembly has an incident end and an emission end, and the incident end of the light cable assembly corresponds to the light source assembly, and is used for transmitting the illumination light emitted by the light source assembly from the incident end to the emission end; and

[0016] a planar optical element, wherein the planar optical element is correspondingly arranged at the emission end of the light cable assembly, and the planar optical element comprises a substrate layer and at least one metasurface layer, wherein the at least one metasurface layer is formed in a superimposed manner on the substrate layer, and each metasurface layer is composed of an arrangement of micro / nano antennas in a subwavelength scale, and is used for regulating the illumination light emitted from the emission end of the light cable assembly.

[0017] According to an embodiment of the present application, the light cable assembly comprises a plurality of optical fibers, and the illumination light is transmitted from the incident end to the emission end by total internal reflection of the optical fibers.

[0018] According to an embodiment of the present application, the metasurface layer of the planar optical element has a one-to-one correspondence between the metasurface structure and the optical fiber, wherein the metasurface structure is designed to regulate the illumination light emitted from the corresponding optical fiber, so that the regulated illumination light covers the entire illumination area.

[0019] According to an embodiment of the present application, the transmittance of all the metasurface structures in the metasurface layer of the planar optical element to the illumination light is consistent at each point in the entire illumination area.

[0020] According to an embodiment of the present application, the transmittance of each of the super surface structures in the super structured surface layer to the illumination light emitted from the corresponding optical fiber is in a sawtooth distribution.

[0021] According to an embodiment of the present application, the planar optical element is spaced apart from the end surface of the exit end of the optical cable assembly.

[0022] According to an embodiment of the present application, the planar optical element is closely attached to the end surface of the exit end of the optical cable assembly.

[0023] According to an embodiment of the present application, the at least one super structured surface layer of the planar optical element comprises a plurality of super structured surface layers, wherein the plurality of super structured surface layers are stacked on the substrate layer, and the plurality of super structured surface layers are respectively designed for phase compensation of illumination light of different wavelengths.

[0024] According to an embodiment of the present application, the planar optical element further comprises at least one gap light transmission layer, wherein the gap light transmission layer is wrapped in one of the super structured surface layers while serving as a substrate for an adjacent other super structured surface layer.

[0025] According to an embodiment of the present application, the light source assembly is a white light source.

[0026] According to an embodiment of the present application, the optical cable assembly further comprises a collimating coupling element, wherein the collimating coupling element is correspondingly arranged in the optical path between the light source assembly and the entrance end of the optical cable assembly, for collimating the illumination light emitted by the light source assembly and coupling the illumination light into the optical cable assembly.

[0027] According to an embodiment of the present application, the micro-nano antenna in the super structured surface layer of the planar optical element is a nano pillar or a nano fin.

[0028] According to another aspect of the present application, the present application further provides an endoscope illumination method, comprising steps of:

[0029] emitting illumination light;

[0030] transmitting the illumination light to a planar optical element; and

[0031] regulating the illumination light via the planar optical element so that the regulated illumination light illuminates an illumination area, wherein the planar optical element comprises a substrate layer and at least one super structured surface layer stacked on the substrate layer, and each of the super structured surface layers is formed by arrangement and combination of micro-nano antennas of sub-wavelength scale.

[0032] According to an embodiment of the present application, the step of transmitting the illumination light to a planar optical element comprises steps of:

[0033] The illumination light is transmitted via total internal reflection through the plurality of optical fibers of the optical cable assembly.

[0034] According to an embodiment of the present application, the step of regulating the illumination light via the planar optical element to make the regulated illumination light uniformly illuminate the entire illumination area, wherein the planar optical element comprises a substrate layer and at least one metasurface layer formed on the substrate layer in a stacked manner, and each of the metasurface layers is formed by an arrangement of sub-wavelength scale micro / nano antennas, comprises the steps of:

[0035] The step of regulating the illumination light via the metasurface structure on the metasurface layer corresponding to the optical fiber to make the regulated illumination light uniformly cover the entire illumination area.

[0036] According to an embodiment of the present application, the step of regulating the illumination light via the planar optical element to make the regulated illumination light uniformly illuminate the entire illumination area, wherein the planar optical element comprises a substrate layer and at least one metasurface layer formed on the substrate layer in a stacked manner, and each of the metasurface layers is formed by an arrangement of sub-wavelength scale micro / nano antennas, comprises the steps of:

[0037] The step of phase compensating the illumination light with a first wavelength via the first metasurface layer in the planar optical element to make the illumination light with the first wavelength cover the entire illumination area; and

[0038] The step of phase compensating the illumination light with a second wavelength via the second metasurface layer in the planar optical element to make the illumination light with the second wavelength cover the entire illumination area, wherein the first metasurface layer and the second metasurface layer are sequentially stacked on the substrate layer, and the first wavelength is not equal to the second wavelength.

[0039] Further objects and advantages of the present application will be more readily apparent from the following description and drawings.

[0040] These and other objects, features and advantages of the present application will become apparent from the following description of the embodiments, drawings and claims. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 A schematic diagram of a conventional endoscope system is shown.

[0042] Figure 2 A schematic diagram of a homogenizing illumination system in the conventional endoscope system described above is shown.

[0043] Figure 3 A system schematic diagram of an endoscope illumination device according to an embodiment of the present application.

[0044] Figure 4 A schematic diagram of a planar optical element of the endoscope illumination device according to the above embodiment of the present application is shown.

[0045] Figure 5 A schematic diagram of the light path of the endoscope illumination device according to the above embodiment of the present application without the planar optical element is shown.

[0046] Figure 6 A schematic diagram of the light intensity distribution of the endoscope illumination device according to the above embodiment of the present application without the planar optical element is shown.

[0047] Figure 7A An example of the endoscope illumination device according to the above embodiment of the present application with the planar optical element is shown.

[0048] Figure 7B A schematic diagram of the light intensity distribution of the endoscope illumination device according to the above embodiment of the present application with the planar optical element is shown.

[0049] Figure 8 A schematic diagram of the principle of the planar optical element according to the above embodiment of the present application is shown.

[0050] Figure 9 Another example of the endoscope illumination device according to the above embodiment of the present application with the planar optical element is shown.

[0051] Figure 10 A schematic diagram of the planar optical element according to the above embodiment of the present application with the micro-nano antenna as nano-pillars is shown.

[0052] Figure 11 A schematic diagram of the planar optical element according to the above embodiment of the present application with the micro-nano antenna as nano-fins is shown.

[0053] Figure 12 A variant of the planar optical element according to the above embodiment of the present application is shown.

[0054] Figure 13A A flowchart of an endoscope illumination method according to an embodiment of the present application is shown.

[0055] Figure 13B A flowchart of one of the steps of the endoscope illumination method according to the above embodiment of the present application is shown. DETAILED DESCRIPTION

[0056] The following description is presented to enable any person skilled in the art to practice the application as claimed. Preferred embodiments are presented in the following description only as examples and modifications thereto can be made by those skilled in the art without departing from the spirit and scope of the application claimed. The present application is well suited to achieving this object with the features described below.

[0057] In the present application, the term "one" of the claims and the description should be understood as "one or more", that is, in one embodiment, the number of one element can be one, and in another embodiment, the number of the element can be multiple. Unless it is explicitly shown in the disclosure of the present application that the number of the element is only one, the term "one" cannot be understood as unique or single, and the term "one" cannot be understood as a limitation on the number.

[0058] In the description of the present application, it should be understood that "first", "second", etc. are only for the purpose of description, and cannot be understood as indicating or implying relative importance. In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, "connected", "connected" should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through a medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0059] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine the different embodiments or examples described in the present application and the features of the different embodiments or examples without contradiction.

[0060] At present, such as Figure 1 and Figure 2As shown, the existing uniform light illumination system 4P is usually provided at the end of the optical cable 3P by a lens group 41P composed of multiple optical lenses, so that the illumination light emitted from the end of the optical cable 3P is first converged and then diverged through the lens group 41P, so as to not only achieve the effect of uniform light, but also diffuse the divergence angle of the illumination light to expand the illumination range. However, the existing uniform light illumination system 4P provided at the end of the optical cable 3P has many problems: on the one hand, the assembly of multiple optical lenses is difficult, not only because the size of the optical lens is small and the surface is curved, so it is difficult to ensure high coaxiality during assembly, but also because the center of the optical lens is difficult to align with the center of the optical cable 3P, so there is an assembly deviation to cause poor uniform light effect; on the other hand, since the endoscope often needs to be subjected to high-temperature disinfection treatment before use, the cooperation between the optical lenses in the existing uniform light illumination system 4P is prone to dislocation, causing the structure of the lens group 41P to be unstable, greatly reducing the stability of the illumination system. In addition, since the existing uniform light illumination system 4P includes multiple optical lenses 41P and is provided at the head of the endoscope, the weight and volume of the head of the endoscope are relatively large, which will greatly inconvenience the operation of the endoscope.

[0061] In order to solve the above problems, with reference to the drawings of the specification Figures 3 to 12 As shown, an endoscope illumination device according to an embodiment of the present application is illustrated. Specifically, as shown in Figure 3 and Figure 4 As shown, the endoscope illumination device 1 can include a light source assembly 10 for emitting illumination light, an optical cable assembly 20, and a planar optical element 30. The optical cable assembly 20 has an incident end 201 and an emission end 202, wherein the incident end 201 of the optical cable assembly 20 corresponds to the light source assembly 10, for transmitting the illumination light emitted by the light source assembly 10 from the incident end 201 to the emission end 202. The planar optical element 30 is correspondingly provided at the emission end 202 of the optical cable assembly 20, and the planar optical element 30 includes a substrate layer 31 and at least one metasurface layer 32, wherein the at least one metasurface layer 32 is formed on the substrate layer 31 in a superposed manner, and each metasurface layer 32 is composed of an array of subwavelength-scale micro-nano antennas 321, for regulating the illumination light emitted from the emission end 202 of the optical cable assembly 20, so that the illumination light can uniformly illuminate the entire illumination area in a large field of view.

[0062] Notably, since the planar optical element 30 adopted by the endoscope illumination device 1 of the present application is implemented as the super-structured surface layer 32 formed on the substrate layer 31 and composed of the micro-nano antenna 321 arranged in sub-wavelength scale, the planar optical element 30 can complete the light beam regulation that can be realized by the refractive optical device such as the lens group with a certain surface curvature in a planar profile, so that the assembly difficulty of the endoscope illumination device 1 of the present application can be greatly reduced, and the misalignment will not occur even when the head of the endoscope is subjected to high-temperature disinfection, which helps to greatly improve the stability of the endoscope structure. At the same time, compared with the traditional lens group, the planar optical element 30 adopted by the present application has smaller volume and lighter weight, and does not need to additionally configure the lens frame for assembling multiple lenses, but only needs to be attached to the end surface of the exit end 202 of the optical cable assembly 20, which has a significant effect on reducing the size and weight of the head of the endoscope, and helps to meet the design requirements of miniaturization and integration of the head of the endoscope.

[0063] According to the above-mentioned embodiments of the present application, the optical cable assembly 20 of the endoscope illumination device 1 includes a plurality of optical fibers 21, and after the illumination light is totally reflected by each of the optical fibers 21, it is emitted at a certain numerical aperture (or opening angle) at the end of the optical fiber 21 (corresponding to the exit end 202 of the optical cable assembly 20). If the planar optical element 30 is not provided, the part of the illumination area corresponding to the center of the optical cable assembly 20 will receive relatively more illumination light, and the part of the illumination area corresponding to the edge of the optical cable assembly 20 will receive relatively less illumination light, resulting in uneven light intensity distribution at the illumination area, which will seriously affect the imaging quality of the endoscope. For example, as shown in Figure 5 For example, as shown in FIG. 4, taking three optical fibers 21 as an example, the 1 area in the illumination area will receive the energy output by all three optical fibers 21; the 2 area in the illumination area will receive the energy output by two optical fibers 21; and the 3 area in the illumination area can only receive the energy output by one optical fiber 21, so that the light intensity distribution in the illumination area is extremely uneven, i.e. the light intensity of the 1 area > the light intensity of the 2 area > the light intensity of the 3 area.

[0064] In fact, since the diameter of the optical cable adopted by the endoscope project is usually about 1.8 mm, and the diameter of the typical multi-mode optical fiber is about 50 um to 60 um, as shown in FIG. 5, the numerical aperture of the multi-mode optical fiber is about 0.1, so that the light intensity distribution in the illumination area will be extremely uneven, i.e. the light intensity of the 1 area > the light intensity of the 2 area > the light intensity of the 3 area. Figure 6As shown, the optical cable assembly 20 of this application typically includes dozens of optical fibers. Thus, without the use of the planar optical element 30, the light intensity distribution of the illumination area will exhibit a characteristic of high intensity in the middle and low intensity at the edges (i.e., the light intensity is lower closer to the outer diameter of the optical cable), which is extremely detrimental to the effective imaging observation of the illumination area.

[0065] After the planar optical element 30 is installed at the emission end 202 of the optical cable assembly 20, the planar optical element 30 can, by selecting appropriate materials and micro / nano structures, cause the metasurface layer 32 to resonate with the electromagnetic field of the illumination light emitted from the emission end 202 of the optical cable assembly 20, thereby inducing a phase abrupt change in the incident light at the interface. In other words, the size or distribution of the micro / nano antennas in the metasurface layer 32 of the planar optical element 30 changes according to a certain rule, so that the wavefront of the illumination light (i.e., the incident light) can be correspondingly modulated to deflect at a design angle. It is understood that the deflection angle of the illumination light when the metasurface layer 32 of the planar optical element 30 modulates the illumination light is generally different from that of normal refracted light, i.e., as... Figure 8 The abnormal refracted light shown; in particular, the metasurface layer 32 can be designed such that the abnormal refracted light and the normal refracted light are on the same side of the interface normal, or it can be designed such that the abnormal refracted light and the normal refracted light are on different sides of the interface normal.

[0066] For example, such as Figure 8 As shown, the metasurface layer 32 of the planar optical element 30 can satisfy the following refractive model: Where φ is the phase change introduced by the metasurface layer 32.

[0067] Preferably, such as Figure 7A and Figure 7B As shown, the metasurface layer 32 of the planar optical element 30 has metasurface structures 320 corresponding one-to-one with the optical fibers 21. These metasurface structures 320 are designed to modulate the illumination light emitted from the corresponding optical fibers 21, ensuring that the modulated illumination light covers the entire illumination area. Under the control of the corresponding metasurface structures 320, the deflection angle of the illumination beam transmitted through each optical fiber 21 can cover the entire illumination area (i.e., the desired illumination range), allowing all illumination beams transmitted through the optical fibers 21 to overlap within the entire illumination area, thereby improving the uniformity of light intensity distribution in the illumination area.

[0068] More preferably, the transmittances of all the super- surface structures 320 in the meta- surface layer 32 of the planar optical element 30 to the illumination light are distributed in a peak-and-valley pattern, so that the superimposed sum of the transmittances of all the super- surface structures 320 to the illumination light remains consistent (i.e. substantially equal) everywhere over the illumination area, to ensure that the illumination intensity everywhere over the illumination area is substantially consistent.

[0069] Most preferably, as shown in FIG. 3B, the transmittances of all the super- surface structures 320 in the meta- surface layer 32 of the planar optical element 30 to the illumination light are distributed in a peak-and-valley pattern, so that the superimposed sum of the transmittances of all the super- surface structures 320 to the illumination light remains equal everywhere over the illumination area. It can be appreciated that the distribution of the transmittances is positively correlated with the distribution of the illumination intensity, i.e. the greater the transmittance, the greater the corresponding illumination intensity. Figure 7B

[0070] Exemplarily, as shown in FIG. 2B, the light paths between the optical fibers 21 of the optical cable assembly 20 and the planar optical element 30 are as shown in FIG. 2B, and the super- surface structures 320 in the meta- surface layer 32 are designed so that the transmittances corresponding to the three optical fibers 21 are respectively distributed according to the curves 1, 2 and 3 as shown in FIG. 2B, so that the superimposed sum of the transmittances of the illumination light emitted by the three optical fibers 21 after passing through the meta- surface layer 32 is consistent (i.e. substantially equal), i.e. the illumination intensity in different sub-areas (such as the A area, the B area and the C area as shown in FIG. 2B) of the entire illumination area remains uniform (such as the curve 4 as shown in FIG. 2B). Figure 7A Figure 7B Figure 7A Figure 7B

[0071] It is worth noting that since the super- surface structures in the meta- surface layer 32 of the planar optical element 30 of the present application play a regulatory role on the optical near field (i.e. an optical path less than the wavelength order), in an example of the present application, as shown in FIG. 1B, the planar optical element 30 can be arranged spaced apart from the end face of the exit end 202 of the optical cable assembly 20, i.e. there is a certain spacing between the planar optical element 30 and the end face of the exit end 202 of the optical cable assembly 20, which helps to increase the difficulty and flexibility of assembly to a certain extent. Of course, in another example of the present application, as shown in FIG. 1C, the planar optical element 30 can also be closely attached to the end face of the exit end 202 of the optical cable assembly 20, so as to further reduce the size of the head of the endoscope. Figure 7A Figure 9

[0072] In addition, the micro- nano antennas 321 in the meta- surface layer 32 can be but not limited to implemented as nano pillars (such as Figure 10 ​​​​​​​(as shown) or nanofins (such as) Figure 11 (as shown), so that the deflection angle and transmittance of the illumination light can be controlled by selecting and adjusting the radius or height of the nanopillars, or by adjusting the rotation angle of the nanofins.

[0073] Specifically, the substrate layer 31 of the planar optical element 30 can be, but is not limited to, made of common high-transmittance materials such as SiO2, and the thickness of the substrate layer 31 can be designed according to actual needs, generally controlled within millimeters and below. The metasurface layer 32 of the planar optical element 30 can be made of materials such as TiO2, and the size of the micro / nano antenna 321 in the metasurface layer 32 is generally on the wavelength scale, such as around hundreds of nanometers. For example, the transmission intensity and phase distribution of the nanopillars are directly related to their size, and the phase range can cover 2π. Therefore, the endoscope illumination device 1 of this application can select a suitable nanopillar size distribution according to the required illuminance angle distribution and intensity distribution to regulate the illumination light emitted from the optical fiber 21, thereby achieving uniform illumination of the entire illumination area.

[0074] It is worth mentioning that, since different human tissues respond differently to illumination light of different wavelengths, in practical applications, the light source component 10 of the endoscope illumination device 1 of this application can emit illumination light of different wavelengths. For example, when observing blood vessels, the light source component 10 emits red light for illumination to make the observation more obvious. Furthermore, to meet the need for adjusting illumination light of different wavelengths, such as... Figure 12 The diagram shows a modified embodiment of the planar optical element 30 of the endoscope illumination device 1 according to the above embodiments of this application. The at least one metasurface layer 32 of the planar optical element 30 may include a plurality of metasurface layers 32, wherein the plurality of metasurface layers 32 are stacked on the substrate layer 31, and the plurality of metasurface layers 32 are respectively designed to perform phase compensation for illumination light of different wavelengths, so that the deflection angle of illumination light of different wavelengths after passing through the planar optical element 30 can reach the required illumination range, and at the same time, the uniformity requirement of illumination can be met.

[0075] Preferably, such as Figure 12As shown, the planar optical element 30 further comprises at least one gap light-transmitting layer 33, wherein the gap light-transmitting layer 33 is coated on one of the metasurface layers 32 and serves as a substrate for the adjacent other metasurface layer 32 to block the light field coupling interference between different layers of metasurface structures. It is worth noting that the gap light-transmitting layer 33 covers the gaps between the micro / nano antennas 321 in the metasurface layer 32 and does not affect the light transmission efficiency of the planar optical element 30; in addition, the thickness of the gap light-transmitting layer 33 can also be controlled to be on the order of the wavelength of hundreds of nanometers, which will not affect the miniaturization and integration of the endoscope head.

[0076] As shown, the planar optical element 30 further comprises at least one gap light-transmitting layer 33, wherein the gap light-transmitting layer 33 is coated on one of the metasurface layers 32 and serves as a substrate for the adjacent other metasurface layer 32 to block the light field coupling interference between different layers of metasurface structures. It is worth noting that the gap light-transmitting layer 33 covers the gaps between the micro / nano antennas 321 in the metasurface layer 32 and does not affect the light transmission efficiency of the planar optical element 30; in addition, the thickness of the gap light-transmitting layer 33 can also be controlled to be on the order of the wavelength of hundreds of nanometers, which will not affect the miniaturization and integration of the endoscope head. Figure 12 As shown, the planar optical element 30 further comprises at least one gap light-transmitting layer 33, wherein the gap light-transmitting layer 33 is coated on one of the metasurface layers 32 and serves as a substrate for the adjacent other metasurface layer 32 to block the light field coupling interference between different layers of metasurface structures. It is worth noting that the gap light-transmitting layer 33 covers the gaps between the micro / nano antennas 321 in the metasurface layer 32 and does not affect the light transmission efficiency of the planar optical element 30; in addition, the thickness of the gap light-transmitting layer 33 can also be controlled to be on the order of the wavelength of hundreds of nanometers, which will not affect the miniaturization and integration of the endoscope head. Figure 12 As shown, the planar optical element 30 further comprises at least one gap light-transmitting layer 33, wherein the gap light-transmitting layer 33 is coated on one of the metasurface layers 32 and serves as a substrate for the adjacent other metasurface layer 32 to block the light field coupling interference between different layers of metasurface structures. It is worth noting that the gap light-transmitting layer 33 covers the gaps between the micro / nano antennas 321 in the metasurface layer 32 and does not affect the light transmission efficiency of the planar optical element 30; in addition, the thickness of the gap light-transmitting layer 33 can also be controlled to be on the order of the wavelength of hundreds of nanometers, which will not affect the miniaturization and integration of the endoscope head. Figure 12 As shown, the planar optical element 30 further comprises at least one gap light-transmitting layer 33, wherein the gap light-transmitting layer 33 is coated on one of the metasurface layers 32 and serves as a substrate for the adjacent other metasurface layer 32 to block the light field coupling interference between different layers of metasurface structures. It is worth noting that the gap light-transmitting layer 33 covers the gaps between the micro / nano antennas 321 in the metasurface layer 32 and does not affect the light transmission efficiency of the planar optical element 30; in addition, the thickness of the gap light-transmitting layer 33 can also be controlled to be on the order of the wavelength of hundreds of nanometers, which will not affect the miniaturization and integration of the endoscope head. Figure 12 As shown, the planar optical element 30 further comprises at least one gap light-transmitting layer 33, wherein the gap light-transmitting layer 33 is coated on one of the metasurface layers 32 and serves as a substrate for the adjacent other metasurface layer 32 to block the light field coupling interference between different layers of metasurface structures. It is worth noting that the gap light-transmitting layer 33 covers the gaps between the micro / nano antennas 321 in the metasurface layer 32 and does not affect the light transmission efficiency of the planar optical element 30; in addition, the thickness of the gap light-transmitting layer 33 can also be controlled to be on the order of the wavelength of hundreds of nanometers, which will not affect the miniaturization and integration of the endoscope head.

[0077] It is worth mentioning that in an example of the present application, the light source assembly 10 can be implemented as a white light source, such as an LED, a halogen lamp or a laser light source, and a combination thereof, but is not limited thereto, as long as it meets the illumination requirements of the endoscope application scenario.

[0078] According to the above embodiments of the present application, asFigure 3 As shown, the optical cable assembly 20 of the endoscope illumination device 1 can further comprise a collimating coupling element 22, wherein the collimating coupling element 22 is correspondingly disposed in the optical path between the light source assembly 10 and the incident end 201 of the optical cable assembly 20, for collimating the illumination light emitted via the light source assembly 10 and coupling the illumination light into the optical fiber 21 of the optical cable assembly 20.

[0079] Exemplary method

[0080] With reference to the drawings Figure 13A and Figure 13B As shown, an endoscope imaging method according to an embodiment of the present application is illustrated. Specifically, as shown in Figure 13A The endoscope imaging method can comprise the steps of:

[0081] S100: emitting illumination light;

[0082] S200: transmitting the illumination light to a planar optical element 30; and

[0083] S300: regulating the illumination light via the planar optical element 30 to illuminate an illumination region, wherein the planar optical element 30 comprises a substrate layer 31 and at least one metasurface layer 32 formed in a stacked manner on the substrate layer 31, and each of the metasurface layers 32 is formed by an arrangement of subwavelength-scale micro / nano antennas 321.

[0084] It is worth noting that, according to the above-mentioned embodiments of the present application, in the step S200 of the endoscope imaging method: the illumination light is transmitted via the plurality of optical fibers 21 of the optical cable assembly 20 by total internal reflection.

[0085] Meanwhile, in the step S300 of the endoscope imaging method:

[0086] the illumination light emitted from the corresponding optical fiber 21 is regulated via the metasurface structure 321 on the metasurface layer 32 corresponding to the optical fiber 21, so that the regulated illumination light covers the entire illumination region.

[0087] It is worth mentioning that, in an example of the present application, as shown in Figure 13B The step S300 of the endoscope imaging method can comprise the steps of:

[0088] S310: phase compensating the illumination light having a first wavelength via a first metasurface layer in the planar optical element to cover the entire illumination region; and

[0089] S320: phase compensating, via a second metasurface layer in the planar optical element, illumination light having a second wavelength to cause the illumination light having the second wavelength to cover the entire illumination area, wherein the first metasurface layer and the second metasurface layer are sequentially superposed on the substrate layer, and the first wavelength is not equal to the second wavelength.

[0090] It will be understood that the configurations and / or approaches described herein are exemplary in nature, and that these specific embodiments or examples are not to be considered in a limiting sense, because numerous variations are possible. The specific routines or methods described herein can represent one or more of any number of processing strategies. As such, various acts illustrated and / or described can be performed in the sequence illustrated and / or described, in other sequences, in parallel, or omitted. Likewise, the order of the above-described processes can be altered.

[0091] The above description of disclosed aspects is intended to be illustrative, and not restrictive. Many embodiments and applications other than the examples provided would be apparent upon reading the above description. The aspects of the disclosure in which an exclusive property or privilege is claimed are defined in the following claims, and the exclusive property or privilege is not to be construed as limited to the implementations described herein. The scope of the disclosure should be determined, not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The disclosures of all articles and references referred to herein are incorporated herein by reference.

[0092] Those skilled in the art will understand that the embodiments of the present application described above and illustrated in the accompanying drawings are presented by way of example only and not limitation. It is intended that the present application's full and effective scope should be defined by the claims to be presented below. The principles and uses of the present application have been explained fully with illustrative embodiments. Various modifications to these embodiments could be made by a person skilled in the art without departing from the scope of the present application as defined in the claims.

Claims

1. An endoscope illuminating device characterized by comprising: The application comprises: a light source assembly, wherein the light source assembly is configured to emit illumination light; an optical cable assembly, wherein the optical cable assembly has an incident end and an exit end, and the incident end of the optical cable assembly corresponds to the light source assembly, and is configured to transmit the illumination light emitted by the light source assembly from the incident end to the exit end; and a planar optical element, wherein the planar optical element is correspondingly arranged at the exit end of the optical cable assembly, and the planar optical element comprises a substrate layer and at least one metasurface layer, wherein the at least one metasurface layer is formed on the substrate layer in a stacked manner, and each of the metasurface layers is composed of an arrangement of micro / nano antennas with subwavelength scale, and is configured to control the illumination light emitted from the exit end of the optical cable assembly; wherein the optical cable assembly comprises a plurality of optical fibers, and is configured to transmit the illumination light from the incident end to the exit end through total internal reflection of the optical fibers; wherein the metasurface layers of the planar optical element have metasurface structures corresponding to the optical fibers, and the metasurface structures are designed to control the illumination light emitted from the corresponding optical fibers, so that the controlled illumination light covers the entire illumination area; wherein the transmittances of all the metasurface structures in the metasurface layers of the planar optical element to the illumination light are consistent at each point of the entire illumination area; and wherein the transmittances of each of the metasurface structures in the metasurface layers to the illumination light emitted from the corresponding optical fibers are distributed in a peak-and-valley manner.

2. The endoscope illumination device of claim 1, wherein, The planar optical element is arranged at a distance from the end face of the exit end of the optical cable assembly.

3. The endoscope illumination device of claim 1, wherein, The planar optical element is closely attached to the end face of the exit end of the optical cable assembly.

4. The endoscope illumination device of claim 1, wherein, The at least one metasurface layer of the planar optical element comprises a plurality of metasurface layers, wherein the plurality of metasurface layers are stacked on the substrate layer, and the plurality of metasurface layers are respectively designed to compensate for the phase of illumination light with different wavelengths.

5. The endoscope illumination device of claim 4, wherein, The planar optical element further comprises at least one gap light transmission layer, wherein the gap light transmission layer is wrapped around one of the metasurface layers, and serves as the substrate of another adjacent metasurface layer.

6. The endoscope illumination device of claim 1, wherein, The light source assembly is a white light source.

7. The endoscope illuminator device of claim 1, wherein, The optical cable assembly further comprises a collimating coupling element, wherein the collimating coupling element is correspondingly arranged in the optical path between the light source assembly and the incident end of the optical cable assembly, and is configured to collimate the illumination light emitted by the light source assembly, and couple the illumination light into the optical cable assembly.

8. The endoscope illumination device of claim 1, wherein, The micro / nano antennas in the metasurface layers of the planar optical element are nano pillars or nano fins.

9. An endoscope illumination method characterized by, The application comprises the steps of: emitting illumination light; transmitting the illumination light to a planar optical element; and controlling the illumination light via the planar optical element, so that the controlled illumination light uniformly illuminates the entire illumination area, wherein the planar optical element comprises a substrate layer and at least one metasurface layer formed on the substrate layer in a stacked manner, and each of the metasurface layers is composed of an arrangement of micro / nano antennas with subwavelength scale. The step of transmitting the illumination light to a planar optical element comprises the steps of: transmitting the illumination light via a plurality of optical fibers of an optical cable assembly by total internal reflection; wherein the step of regulating the illumination light via the planar optical element to make the regulated illumination light uniformly illuminate the entire illumination area, wherein the planar optical element comprises a substrate layer and at least one metasurface layer formed on the substrate layer in a stacked manner, and each of the metasurface layers is composed of an arrangement of subwavelength-scale micro / nanoantennas, comprises the steps of: regulating the illumination light emitted from the corresponding optical fiber via the metasurface structure on the metasurface layer corresponding to the optical fiber to make the regulated illumination light uniformly cover the entire illumination area; wherein the transmittance of all the metasurface structures in the metasurface layer of the planar optical element to the illumination light remains consistent at the superposition sum of the transmittance of the metasurface structures at all places in the entire illumination area; wherein the transmittance of each of the metasurface structures in the metasurface layer to the illumination light emitted from the corresponding optical fiber is in a bimodal distribution.

10. The endoscope illumination method of claim 9, wherein, The step of regulating the illumination light via the planar optical element to make the regulated illumination light uniformly illuminate the entire illumination area, wherein the planar optical element comprises a substrate layer and at least one metasurface layer formed on the substrate layer in a stacked manner, and each of the metasurface layers is composed of an arrangement of subwavelength-scale micro / nanoantennas, comprises the steps of: phase compensating the illumination light with a first wavelength via a first metasurface layer in the planar optical element to make the illumination light with the first wavelength cover the entire illumination area; and phase compensating the illumination light with a second wavelength via a second metasurface layer in the planar optical element to make the illumination light with the second wavelength cover the entire illumination area, wherein the first metasurface layer and the second metasurface layer are sequentially stacked on the substrate layer, and the first wavelength is not equal to the second wavelength.

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