CN202018537U - Optical-tweezers device based on wave-front phase modulation - Google Patents

Abstract

The utility model relates to an optical tweezers device based on wavefront phase modulation, belongs to the field of applied optics technology, and is mainly used in the fields of optical micro-manipulation, interaction between light and matter, and the like. The device is composed of a light source emitting part, a beam diameter adjuster, a phase wavefront adjuster, and an optical focusing part; the light source emitting part is sequentially provided with a beam diameter adjuster, a phase wavefront adjuster and an optical focusing part in the direction of the outgoing beam. The phase wavefront modifier of is a ring phase wavefront modifier with a phase topology. The utility model has the advantages of realizing regulation and control of optical tweezers, convenient regulation and control, high utilization rate of light energy, simple system and the like.

Description

An optical tweezers device based on wavefront phase modulation

Technical field:

The utility model belongs to the technical field of applied optics, relates to a light intensity adjustment system in a focus area of a focusing optical system, in particular to an optical tweezers device based on wavefront phase modulation. It is mainly used in the fields of optical micro-manipulation and interaction between light and matter.

Background technique:

As early as 1970, A. Ashkin of Bell Laboratories successfully tweezed and moved small glass beads in aqueous solution by using the three-dimensional potential well of multi-beam laser. After that, the technology of laser tweezing particles has been continuously improved, and the particles that can be captured are getting smaller and smaller. In 1985, A. Ashkin began to use single beam tweezers to lift tiny organisms such as bacteria and viruses. In 1987, he used a laser of 1064 nanometers. The virus was successfully tweezed. In the following 20 years, this technology has been widely used and developed, and derived far-field optical tweezers such as lens fiber optical tweezers, microlens array optical tweezers, and holographic array optical tweezers, which can be applied to some special fields, and have become Research tools in many disciplines such as biomedicine, chemistry, physics, spectroscopy, microfabrication, etc. In the 21st century with the rapid development of nanotechnology and life science, the research and application of optical tweezers technology, which is a powerful tool in these two fields, has been developed rapidly. Especially in the field of life science, optical tweezers has become the Indispensable and efficient tool for macromolecular behavior. In recent years, the coherent mode of two beams of light has been used to form adjustable optical tweezers, and the trapped particles can be continuously rotated by changing the frequency difference or optical path difference of the two beams (K.Dholakia et al. al, "Simultaneous micromanipulation in multiple planes using a self reconstructing light beam," Nature 2002, 419, 145, and "Creation and manipulation of three-dimensional optically trapped structures," Science 2002, 296, p1101-1103), although this The prior art of tweezers has certain advantages, but there are still following deficiencies:

1) Adjustable optical tweezers require two beams of light sources to be coherent to form an interference pattern to form optical tweezers. The structure of the device is complex and there are many components.

2) The particles trapped in the optical tweezers device are captured and released by switching the light source or adjusting the light intensity greatly, which has poor control flexibility and even affects the service life of the device.

Contents of the invention

In order to solve the above-mentioned problems in the prior art, the utility model provides a device for realizing optical tweezers with few parts, high utilization rate of light energy and simple system.

The technical scheme adopted by the utility model to solve the above-mentioned technical problems is a device for realizing optical tweezers, which is composed of a light source emitting part, a beam diameter adjuster, a phase wave front adjuster, and an optical focusing part; It is equipped with a beam diameter adjuster, a phase wavefront adjuster and an optical focusing component, and is characterized in that the phase wavefront adjuster is a ring phase wavefront adjuster with a phase topology.

The annular phase wave front adjuster with phase topology number described in the utility model is a component with variable area radius. The adjustment phase changes in a spiral shape, and the relative radius and topological number of the wavefront phase adjuster are adjustable.

The annular phase wave front adjuster with phase topology number described in the utility model is a programmable phase spatial light modulator, a programmable liquid crystal optical phase control device, and an optical-mechanical-electrical integrated phase control device.

The beam diameter adjuster described in the utility model is an optical component for beam expansion with adjustable beam expansion ratio.

Preferably, the beam expander optical component with adjustable beam expander magnification is a Galilean beam expander or a Capeton beam expander.

Preferably, the light source emitting part is a helium-neon laser.

Preferably, the optical focusing component is a Nikon plan apochromat objective lens.

Compared with the prior art, the utility model has advantages and beneficial effects as follows:

1) Only one beam of light is used to form controllable optical tweezers, the device has a simple structure and few components.

2) The particles trapped in the optical tweezers device can be captured and released by adjusting the phase, the control method is flexible, and the device has a long service life.

3) The device has a simple structure, is convenient to operate, and is easy to realize automation.

4) It can be conveniently adjusted at the position of the particle, and new optical tweezers are continuously formed to capture the particle, and then transported to the destination.

Description of drawings

Fig. 1 is the system structure schematic diagram of the utility model embodiment;

Fig. 2 is the schematic diagram of the wavefront adjuster of the embodiment of the utility model;

Fig. 3 is the optical tweezers distribution diagram of the utility model embodiment;

Fig. 4 is the optical tweezers distribution diagram of the utility model embodiment

Fig. 5 is the optical tweezers distribution diagram of the utility model embodiment

Fig. 6 is a distribution diagram of the optical tweezers of the embodiment of the present invention.

Detailed ways

The utility model is further described in detail below in conjunction with the accompanying drawings. The following examples are better application forms of the utility model, but the following examples should not be regarded as a limitation of the utility model.

Example

The following sections of this example describe a setup for implementing optical tweezers:

As shown in Figure 1, the device for realizing optical tweezers of the present utility model comprises a helium-neon laser 1, a Cape Town type beam expander 2, a programmable phase-type spatial light modulator 3 and a Nikon plan apochromatic objective lens 4. The Cape Town type beam expander 2, the programmable phase spatial light modulator 3 and the Nikon plan apochromat objective lens 4 are sequentially arranged on the light output path of the He-Ne laser 1.

When working, the coherent beam emitted by the He-Ne laser 1 passes through the Cape-type beam expander 2, and the Cape-type beam expander 2 expands the beam, and the expanded laser beam passes through the programmable phase-type spatial light modulator 3 , as shown in FIG. 2 , the programmable phase spatial light modulator 3 adjusts the wavefront phase distribution of the incident laser beam in a helical phase change, so that the phase distribution presents a helical phase change, and has a helical phase wavefront After the laser beam is focused by the Nikon plan apochromat objective lens 4, as shown in Figure 3-6, optical tweezers are formed in the focal area.

其中i为单位虚数，

为光束横截面上的方向角坐标，m为相位拓朴数。环形相位波前指的是光束波前相位在具有相位拓扑分布同时还具有在横向呈现环带状分布。在使用带有相位拓朴数的环形相位波前调节器这一技术手段时，可以通过可编程相位型空间光调制器、可编程液晶光学相位控制器件和光机电集成相位控制器件来实现，例如，选择可编程相位型空间光调制器，可编程相位型空间光调制器是现有产品化的器件，国际著名品牌供应商包括HOLOEYE、BNS、HAMAMATSU等公司，分为反射式和透射式两种，均可以通过图形用户界面软件任意调节反射或透过光束的波前相位，本实用新型中将带有相位拓朴数的环形相位波前分布函数导入可编程相位型空间光调制器的图形用户界面软件，即可实现光束的带有相位拓朴数的环形相位波前分布，本实施例中采用的具体带有相位拓朴数的环形相位波前调节器为HOLOEYE公司型号为LC-R 2500空间光调制器。The phase wavefront adjuster is a ring-shaped phase wavefront adjuster with a phase topology number, and after the beam is adjusted by the phase wavefront adjuster, the wavefront of the beam has a topological distribution. For example, the phase topological distribution is selected as

where i is a unit imaginary number,

is the direction angle coordinate on the cross-section of the beam, and m is the phase topology number. The annular phase wavefront means that the wavefront phase of the beam has a phase topological distribution and also has a ring-like distribution in the transverse direction. When using the technical means of ring phase wavefront adjuster with phase topology number, it can be realized by programmable phase spatial light modulator, programmable liquid crystal optical phase control device and optomechanical integrated phase control device, for example, Select the programmable phase spatial light modulator. The programmable phase spatial light modulator is an existing productized device. International famous brand suppliers include HOLOEYE, BNS, HAMAMATSU and other companies, which are divided into two types: reflective and transmissive. The wavefront phase of the reflected or transmitted light beam can be adjusted arbitrarily through the graphical user interface software. In the utility model, the annular phase wavefront distribution function with the phase topology number is introduced into the graphical user interface of the programmable phase spatial light modulator Software can realize the annular phase wavefront distribution with the phase topology number of the light beam. The specific annular phase wavefront regulator with the phase topology number used in this embodiment is the LC-R 2500 space of the HOLOEYE company model light modulator.

The key of the utility model is to realize the purpose of forming optical tweezers by means of adjusting the wavefront phase of the laser beam by means of an annular phase wavefront adjuster with a phase topology number. All similar structures, methods and similar changes of the utility model should be included in the protection scope of the utility model.

Claims (7)

1. An optical tweezers device based on wavefront phase modulation, which is composed of a light source emitting part, a beam diameter adjuster, a phase wavefront adjuster, and an optical focusing part; the light source emitting part is sequentially equipped with beam diameter adjustments in the direction of the outgoing beam A device, a phase wavefront adjuster and an optical focusing component are characterized in that: the phase wavefront adjuster is an annular phase wavefront adjuster with a phase topology. 2. The optical tweezers device based on wavefront phase modulation according to claim 1, characterized in that: said annular phase wavefront adjuster with phase topology is a component with a variable area radius. 3. The optical tweezers device based on wavefront phase modulation according to claim 1, characterized in that: the described annular phase wavefront adjuster with phase topology number is a programmable phase type spatial light modulator, Program liquid crystal optical phase control devices, optomechanical integrated phase control devices. 4. The optical tweezers device based on wavefront phase modulation according to claim 1, characterized in that: said beam diameter adjuster is a beam expansion optical component with adjustable beam expansion magnification. 5. The optical tweezers device based on wavefront phase modulation according to claim 5, characterized in that: the beam expansion optical component with adjustable beam expansion magnification is a Galilean beam expander or a Capeton type beam expander. beam mirror. 6. The optical tweezers device based on wavefront phase modulation according to claim 1, characterized in that: said light source emitting part is a He-Ne laser. 7. The optical tweezers device based on wavefront phase modulation according to claim 1, characterized in that: said optical focusing component is a Nikon plan apochromat objective lens.

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