CN-121995656-A - Optical device capable of actively adjusting focal plane position and preparation method and application thereof

Abstract

The invention discloses an optical device for actively adjusting the focal plane position, a preparation method and application thereof, wherein the optical device comprises a thermo-optical element, a lens and a lens, wherein the thermo-optical element is a variable refractive index transparent sheet with refractive index changing along with temperature; the heating element is provided with a heating part and an electric wire connected with the heating part, the heating part is arranged on one surface of the thermo-optical element, the refractive index of the thermo-optical element is regulated and controlled through the temperature change of the heating part so as to adjust the focal plane position, the heating part is provided with a light through hole exposing the thermo-optical element, and the electric wire is suitable for being connected with an adjustable voltage source. The optical device is arranged between a sample and an objective lens, the temperature of a thermo-optical element is adjusted by controlling the working voltage of the heating element, the density of the thermo-optical element is changed, the refractive index of the thermo-optical element is changed, the zooming function is further realized, the purpose of dynamically regulating and controlling the focal plane is realized, the regulation and control of single step length smaller than 10 nm can be realized, and the optical device is suitable for dynamic optical scenes.

Inventors

• ZHANG LEFEI
• HONG MINGHUI

Assignees

• 厦门大学

Dates

Publication Date

20260508

Application Date

20260121

Claims (10)

1. 1. An optical device for actively adjusting the position of a focal plane, comprising: a thermo-optical element that is a variable refractive index transparent sheet having a refractive index that varies with temperature; The heating element is provided with a heating part and an electric wire connected with the heating part, the heating part is arranged on one surface of the thermo-optical element, the refractive index of the thermo-optical element is regulated and controlled through the temperature change of the heating part so as to adjust the focal plane position, the heating part is provided with a light through hole exposing the thermo-optical element, and the electric wire is suitable for being connected with an adjustable voltage source.
2. 2. The optical device of claim 1, further comprising a thermally insulating tape that is wrapped around the thermo-optical element and the heating element and forms a relief opening corresponding to the light passing aperture.
3. 3. The optical device of claim 1, wherein the refractive index of the thermo-optical element varies linearly with temperature.
4. 4. The optical device of claim 1, wherein the thermo-optic element has a visible band transmittance of 90% or greater and a thermo-optic coefficient on the order of 10 -4 .
5. 5. The optical device of any one of claims 1-4, wherein the thermo-optical element is a PC sheet polymerized from bisphenol a and diphenyl carbonate.
6. 6. The optical device of claim 1, wherein the heating portion is attached to the surface of the thermo-optical element by an epoxy glue.
7. 7. The optical device of claim 1, wherein the material of the heating portion is ceramic.
8. 8. The optical device of claim 1, wherein the heating portion is located at a geometric center of a surface of the thermo-optical element.
9. 9. A method of manufacturing an optical device for actively adjusting the focal plane position, comprising the steps of: Step 1, providing a thermo-optical element which is a variable refractive index transparent sheet with a refractive index changing with temperature; Step 2, providing a heating element, wherein the heating element is provided with a heating part with a luminous hole and an electric wire connected with the heating part; step 3, the heating part is arranged on one surface of the thermo-optical element in a bonding way, and the electric wires are led out from two opposite sides of the heating part; And 4, providing a heat-insulating adhesive tape, coating the heat-insulating adhesive tape on the outer sides of the thermo-optical element and the heating element, and forming an avoidance opening corresponding to the light through hole.
10. 10. Use of an optical device according to any of claims 1-8, wherein the optical device is placed between a sample and an objective lens of an optical imaging system, the electric wire is connected to an adjustable voltage source, and the focal plane position of the optical imaging system is adjusted by adjusting the output voltage of the adjustable voltage source, controlling the temperature variation of the heating section, so as to adjust the refractive index of the thermo-optical element.

Description

Optical device capable of actively adjusting focal plane position and preparation method and application thereof Technical Field The invention relates to the technical field of optical imaging, in particular to an optical device for actively adjusting the focal plane position, a preparation method and application thereof. Background With the development of technology, the resolution of optical imaging is continuously improved, for example, microspheres are used as nano imaging lenses, and the method is an effective method for improving the resolution of an optical microscope. Due to the super-resolution capability, the characteristic of no need of marking, good compatibility with a traditional microscope, real-time imaging and low cost, microsphere nano imaging is widely focused by researchers, and has wide application prospects in the fields of chip detection, biomedical treatment and the like. However, high resolution imaging systems are generally faced with a technical bottleneck with limited depth of field. Taking microsphere nano imaging as an example, the method is limited by the size and surface curvature characteristics of the microsphere, the depth of field of amplified imaging is usually only hundreds of nanometers, and the requirement of high-precision and dynamic precise regulation and control of the focal plane position in the imaging process can be met. At present, the mainstream focal plane regulation and control mode in the industry is mechanical regulation and control, the mode mainly depends on a transmission system formed by a stepping motor and a synchronous belt to realize position regulation, but the mode has a plurality of defects which are difficult to overcome, namely, firstly, the regulation and control precision is insufficient, the single minimum regulation and control step length can only reach 10 nm and can not meet the imaging requirement of higher precision, secondly, the operation stability is poor, vibration is easy to generate in the regulation and control process to influence the imaging quality, thirdly, obvious return errors exist, micrometer positioning deviation can occur in the transmission system when the positive and negative rotation is switched due to the non-ideal characteristics of a mechanical structure and materials, and fourthly, the dynamic regulation and control capability is lost, so that the continuous and smooth regulation of the focal plane position is difficult to realize, and the use requirement of a dynamic optical scene can not be adapted. These problems together limit the application of mechanical regulation in diversified and refined high-precision imaging scenes. To solve the mechanical regulation defect, technical exploration of non-mechanical regulation has appeared in the related art. For example, patent CN112068228a discloses a planar focusing lens device based on phonon polarized wave, which adjusts the wave vector of phonon by changing the size of metal antenna or the wave number of incident infrared light to realize focal length adjustment, while avoiding the inherent defect of mechanical transmission, the planar focusing lens device still has obvious limitations that the focusing adjustment depends on a specific phonon polarized wave excitation mechanism, is only suitable for infrared light wave band and cannot adapt to the high precision imaging requirement of visible light wave band, and the adjustment and control process depends on complex excimer excitation and detection system, so that the device integration level is low and is difficult to adapt to the equipment such as traditional optical microscope conveniently. Disclosure of Invention The present invention aims to solve at least to some extent one of the technical problems in the above-described technology. Therefore, the invention aims to provide an optical device for actively adjusting the focal plane position, a preparation method and application thereof, and high-precision dynamic adjustment of the focal plane is realized through the refractive index of a temperature regulating material. To achieve the above object, the present invention provides, in a first aspect, an optical device for actively adjusting a focal plane position, including: a thermo-optical element that is a variable refractive index transparent sheet having a refractive index that varies with temperature; The heating element is provided with a heating part and an electric wire connected with the heating part, the heating part is arranged on one surface of the thermo-optical element, the refractive index of the thermo-optical element is regulated and controlled through the temperature change of the heating part so as to adjust the focal plane position, the heating part is provided with a light through hole exposing the thermo-optical element, and the electric wire is suitable for being connected with an adjustable voltage source. The optical device actively adjusts the focal plane through the extremely simpl