CN104360474A - Electrically-controlled non-diffracting beam forming device based on electrowetting effect and control method thereof - Google Patents

Abstract

The invention provides an electrically-controlled non-diffracting beam forming device based on electrowetting effect and a control method thereof. The device comprises a closed cylindrical container and a control circuit. The closed cylindrical container is full of conductive liquid and insulating liquid provided under the conductive liquid; the conductive liquid and the insulating liquid are identical in density and never dissolves each other; the inner wall of the closed cylindrical container is coated with a conductive film; the conductive film is coated with a hydrophobic coating; the inner bottom wall of the closed cylindrical container is coated with a ring-grating transparent electrode which is coated with a dielectric coating; the control circuit is connected with the ring-grating transparent electrode. The electrically-controlled non-diffracting beam forming device allows a non-diffracting propagating distance and the size of a center light spot to be dynamically adjusted through a control circuit and has the advantages of high realizability, low cost, low response speed and the like.

Description

Based on automatically controlled generating apparatus and the control method of the diffraction light-free of electrowetting effect

Technical field

The present invention relates to biliquid lenticule and generate Beams generation technique field, especially relate to a kind of automatically controlled generating apparatus and control method of the diffraction light-free based on electrowetting effect.

Background technology

Diffraction light-free is one group of particular solution in Maxwell's electromagnetic equation, remains focus condition with light velocity propagation, and the strict solution of null solution Bessel's function form has established it generates Beams basis at occurring in nature, can be applied in following field.First Beams spatial characteristic unchangeability, there is tempting prospect in precision engineering, in the field of precision measurement, adopt almost whole occasions of Gaussian beam that Beams all can be adopted to replace, overcome the out of focus of Gaussian beam, distortion and depth of focus limitation etc., realize the high precision and large measuring range target that surveying instrument is generally expected; Its two diffraction light-free is under the change action of spherical lens, and the effect in the field such as Laser Processing, laser medicine that large aspect ratio is processed is unique; It three is expected to be applied in the field application such as aerospace communication, Energy Transfer, electromagnetic wave shell or electromagnetic wave bullet, particularly in current hot micro electronmechanical and field of nanometer technology in the future.

Although the generating mode of Beams is various, mainly being generated by Conical Lenses of Beams, because the transmission transfer rate of this mode light beam is the highest, only needs a slice optical device, and processing is relatively easy.But, in micro-optical systems, generate Beams be difficult to because of Conical Lenses processing difficulties realize; Generate the correlation theory of Beams in addition according to Conical Lenses, Conical Lenses surface figure accuracy directly affects the quality of the Beams of generation; Secondly under the prerequisite that Conical Lenses basal diameter is certain, the angle of its bottom surface and the conical surface directly determines propagation distance and the center spot size of generated Beams, traditional Conical Lenses face shape machining precision costly, and cannot realize the real-time adjustment of Beams propagation characteristic after machine-shaping; Therefore traditional Beams generating mode greatly limits the range of application of Beams.

Summary of the invention

The object of the invention is to: for prior art Problems existing, a kind of automatically controlled generating apparatus and control method of the diffraction light-free based on electrowetting effect are provided, solving tradition adopts Conical Lenses to generate Beams, the machining precision of its Conical Lenses face shape costly, and cannot realize the problem of the real-time adjustment of Beams propagation characteristic after machine-shaping.

Goal of the invention of the present invention is achieved through the following technical solutions: a kind of automatically controlled generating apparatus of the diffraction light-free based on electrowetting effect, it is characterized in that, this device comprises inclose and describes device and control circuit, conducting liquid and iknsulating liquid is filled with in this container, conducting liquid at lower iknsulating liquid upper, described conducting liquid is identical with the density of iknsulating liquid, and objectionable intermingling, the madial wall of described container is coated with conducting film, the coating of conducting film scribbles hydrophobic coating, the interior diapire of described container is coated with ring grid transparency electrode, the upper of electrode is coated with dielectric coating again, described control circuit is connected with ring grid transparency electrode.

Preferably, described ring grid transparency electrode is made up of the transparency electrode of multiple donut, and each donut is all connected with control circuit, with inclose, ring grid transparency electrode describes that device is coaxial.

Preferably, described conducting liquid is Na ₂so ₄aqueous solution, described iknsulating liquid is C ₁₂h ₂₅br.

Preferably, described conducting liquid contains one or more in NaCl solution, siloxane, halogenated alkane.

Preferably, hydrophobic coating is teflon.

Preferably, described dielectric coating is polyimide or barium titanate.

Preferably, described ring grid transparency electrode is that tin oxide mixes fluorine electro-conductive glass.

Preferably, described control circuit comprises described control circuit and comprises power input, plurality of voltages output interface and the control module for each road magnitude of voltage of controlling plurality of voltages output interface respectively, and described plurality of voltages output interface is corresponding with each ring of ring grid transparency electrode to be connected.

A control method for device described in claim 1, is characterized in that, the method following steps:

(1) angle theta of the two liquid comes into contact conical interface needing control realization is determined;

(2) according to formula the magnitude of voltage U that each ring respectively in control loop grid transparency electrode applies, in formula r inclose describes the internal diameter of device, and r is the radius of each ring of ring grid transparency electrode, and △ n is the refringence of conducting liquid and iknsulating liquid, β ₀for the contact interface of conducting liquid during impressed voltage U=0 and iknsulating liquid is relative to the contact angle between hydrophobic coating, ε ₀for the permittivity of vacuum of hydrophobic coating, ε _rfor conducting liquid is relative to the relative dielectric constant of hydrophobic coating, δ ₁₂for the surface tension between conducting liquid and iknsulating liquid, d is the thickness of hydrophobic coating 3.

Compared with prior art, the present invention has the following advantages:

1. due to the contact interface that Conical Lenses is two liquid, in the manufacture craft of lens, there is not machining, avoid the difficulty that micro-Conical Lenses is difficult to machining;

2. due to the formation continuity between fluid molecule, the surface precision of the circular conical surface that two liquid are formed can reach 0.3nm, and it is close to ideal circular conical surface type, and relatively traditional mach Conical Lenses can generate more preferably Beams;

3. because the spatial distance of the Beams generated by Conical Lenses is inversely proportional to the angle of refringence and circular conical surface and bottom surface, therefore two liquid that selective refraction rate is comparatively close, under inclose describes the prerequisite that the cavity volume radius of device is certain, Beams propagation distance can be allowed longer;

4., because biliquid contact circular cone angle can be regulated and controled by Electric Field Distribution, therefore by the adjustment of circuit at each annular transparent electrodes voltage, change the real-time automatically controlled adjustment of parameter that circular cone angle realizes propagating Beams.

Accompanying drawing explanation

Fig. 1 is the half section structural representation of the automatically controlled generating apparatus of diffraction light-free that the present invention is based on electrowetting effect;

Fig. 2 is the structural representation of ring grid transparency electrode;

Fig. 3 is the control circuit principle sketch that multiplex roles voltage exports.

Accompanying drawing mark illustrates:

1 describes device for inclose; 2 is side electrode; 3 is hydrophobic coating; 4 is conducting liquid; 5 is control circuit; 6 is ring grid transparency electrodes; 7 is dielectric coating; 8 is the contact interface of two liquid; 9 is iknsulating liquid; 10 is transparent end cap.

Embodiment

Below in conjunction with the drawings and specific embodiments, the present invention is described in detail.

Embodiment

The automatically controlled generating apparatus of a kind of diffraction light-free based on electrowetting effect of the present invention, it is based on the principle of electrowetting effect, adopt many concentric rings grid electrode according to the distribution of adjustment space electric field, control refractive index is different and two immiscible liquid form face, interface type for conical, and changes the angle of Electric Field Distribution change conical interface to realize the real-time adjustment of the characteristic parameter of Beams according to certain mapping relations.Mainly be applicable to Beams in micro-optic and Beams array, in the scenes such as the parameter change especially utilizing Beams spatial invariant feature to need in photocontrol and optical operation process.

Primarily of inclose, concrete structure of the present invention, as shown in Figure 1, describes that device 1 and control circuit 5 are formed.This inclose describes in device 1 and fills with refractive index difference, density identical and mutual exclusive conducting liquid 4 and iknsulating liquid 9, conducting liquid 4 under, iknsulating liquid 9 is upper, two kinds of liquid are sealed in inclose by transparent glass cover-plate 10 and describe in the cavity volume of device 1, and gas or other liquid can not be had to exist.Because conducting liquid 4 is different with iknsulating liquid 9 refractive index, density is suitable, immiscible, therefore under capillary effect, the contact interface 8 of taper between conducting liquid 4 and iknsulating liquid 9, can be naturally form.The madial wall that inclose describes device 1 is coated with conducting film 2, the coating of conducting film 2 scribbles hydrophobic coating 3.The interior diapire that inclose describes device 1 is coated with ring grid transparency electrode 6, and the upper of electrode is coated with dielectric coating 7 again, with inclose, conducting liquid 4 directly describes that the dielectric coating 7 of device 1 bottom surface contacts.Control circuit 5 is connected with ring grid transparency electrode 6, and the voltage in ring grid transparency electrode 6 on each ring is provided and control by control circuit 5.Certain distribution is obeyed by control circuit 5 electric field adjusted between each ring gate electrode and sidewall, contact interface between conducting liquid and dielectric can be adjusted to the coarse perfect taper reaching 0.3 nanometer of surface topography, thus the parallel beam that can realize irradiating converts Beams to; The cone angle of conical interface that wherein two liquid are formed under ring grid shape transparency electrode 6 control action decides the space length of Beams and the size of center spot, therefore the automatically controlled adjustment to Beams parameter will be realized, according to certain principle adjustment electric field, to control the conical interface cone angle of two liquid comes into contact, realize the automatically controlled adjustment of Beams propagation characteristic.

As shown in Figure 2, ring grid transparency electrode 6 is made up of the transparency electrode of multiple donut, and each donut is all connected with control circuit, and ring grid transparency electrode 6 and inclose describe that device 1 is coaxial.The conducting liquid of the present embodiment is Na ₂so ₄aqueous solution, iknsulating liquid is C ₁₂h ₂₅br.Can contain in NaCl solution, siloxane, halogenated alkane in conducting liquid one or more.Hydrophobic coating is teflon (Teflon AF1600).Dielectric coating is polyimide or barium titanate.Ring grid transparency electrode is that tin oxide mixes fluorine (F TO) electro-conductive glass.

Control circuit comprises described control circuit and comprises power input, plurality of voltages output interface and the control module for each road magnitude of voltage of controlling plurality of voltages output interface respectively.Control module can adopt Programmable Logic Controller.Plurality of voltages output interface is corresponding with each ring of ring grid transparency electrode to be connected.

The control method being controlled the cone angle size of the contact conical surface by control circuit is specially:

(1) angle theta of the two liquid comes into contact conical interface needing control realization is determined;

(2) according to formula the magnitude of voltage U that each ring respectively in control loop grid transparency electrode applies, in formula r inclose describes the internal diameter of device, and r is the radius of each ring of ring grid transparency electrode, and △ n is the refringence of conducting liquid and iknsulating liquid, β ₀for the contact interface of conducting liquid during impressed voltage U=0 and iknsulating liquid is relative to the contact angle between hydrophobic coating, ε ₀for the permittivity of vacuum of hydrophobic coating, ε _rfor conducting liquid is relative to the relative dielectric constant of hydrophobic coating, δ ₁₂for the surface tension between conducting liquid and iknsulating liquid, d is the thickness of hydrophobic coating 3.

Native system also comprises required supporting power supply, mounting platform and relevant collimated laser beam etc.

Principle of work of the present invention is:

The conducting liquid 4 different when refractive index, density is suitable, immiscible is put into an inclose with two kinds of liquid of iknsulating liquid 9 and is described device 1, meeting self-assembling formation contact interface under capillary effect between conducting liquid 4 and iknsulating liquid 9.Due to the difference of two liquid refractivities, its contact interface just can be used as optical interface, secondly, because two fluid densities quite just eliminate the impact of gravity on interface shape, moreover, because iknsulating liquid 9 and inclose describe that the electricity of the madial wall of device 1 infiltrates effect, by the control of the space distribution to electric field, the contact interface of two liquid is become coned face, after along inclose, the parallel beam of Single wavelength describes that the axis of device 1 is irradiated, just Beams can be generated: the principle and the spatial characteristic thereof that generate Beams according to Conical Lenses, when the circular conical surface that two liquid comes into contact interfaces are formed under electric field action, and the angle of the side of circular conical surface and bottom surface is θ, the refringence of two liquid is △ n, when inclose describes that the internal diameter of device 1 is R, salt free ligands spatial distance is z _maxfor:

z _max≈R/(Δn·θ) (1)

Salt free ligands hot spot central diameter d size is:

$d\≈\frac{2.405\mathrm{\λ}}{\mathrm{\Δn}\·\mathrm{\π}\·\mathrm{\θ}}---\left(2\right)$

λ in above formula is the wavelength irradiating parallel Single wavelength light beam, and π is circular constant constant.

Theoretical according to electrowetting effect, the relation between the contact angle β that the liquid comes into contact interface phase corresponding with it of the impressed voltage U on the wherein ring electrode in ring grid shape transparency electrode 6 is formed for the sidewall of hydrostatic column 1 is as follows:

$\cos \mathrm{\β}=\cos {\mathrm{\β}}_0+\frac{{\mathrm{\ϵ}}_0{\mathrm{\ϵ}}_r}{2d{\mathrm{\δ}}_{12}}{U}^2---\left(3\right)$

In above formula, d is the thickness of hydrophobic coating 3, ε 0 and ε r is respectively the permittivity of vacuum of hydrophobic coating 3 and conducting liquid 4 relative dielectric constant relative to hydrophobic coating 3, δ 12 is the surface tension between conducting liquid 4 and iknsulating liquid 9, and during β 0 impressed voltage U=0, two liquid comes into contact interface phases are for the contact angle between hydrophobic coating 3.Allow the contact interface of two liquid form the conical surface under electric field action, the voltage on each ring of ring grid transparency electrode 6 meets following relation:

$U=\sqrt{\frac{(r-R)\cot \mathrm{\β}-A}{B}}---\left(4\right)$

In above formula r is the radius of each ring of ring grid transparency electrode 6.Pass according to the geometric relationship wherein angle theta contact angle β of two liquid comes into contact conical interface is θ=β-90 °, and the voltage that each circulating application in ring grid transparency electrode 6 adds is as follows with the taper angle theta corresponding relation contacting cone interface:

$U=\sqrt{\frac{(R-r)\tan \mathrm{\θ}-A}{B}}---\left(5\right)$

Control circuit 5 adds corresponding voltage to each circulating application in ring grid transparency electrode 6 respectively according to above formula, just can adjust arbitrarily the cone angle of the contact conical surface, thus realize the automatically controlled adjustment of Beams parameter.

The foregoing is only preferred embodiment of the present invention, not in order to limit the present invention, it should be pointed out that all any amendments done within the spirit and principles in the present invention, equivalent replacement and improvement etc., all should be included within protection scope of the present invention.

Claims (9)

1. the automatically controlled generating apparatus of the diffraction light-free based on electrowetting effect, it is characterized in that, this device comprises inclose and describes device and control circuit, conducting liquid and iknsulating liquid is filled with in this container, conducting liquid at lower iknsulating liquid upper, described conducting liquid is identical with the density of iknsulating liquid, and objectionable intermingling, the madial wall of described container is coated with conducting film, the coating of conducting film scribbles hydrophobic coating, the interior diapire of described container is coated with ring grid transparency electrode, the upper of electrode is coated with dielectric coating again, described control circuit is connected with ring grid transparency electrode.

2. the automatically controlled generating apparatus of a kind of diffraction light-free based on electrowetting effect according to claim 1, it is characterized in that, described ring grid transparency electrode is made up of the transparency electrode of multiple donut, each donut is all connected with control circuit, with inclose, ring grid transparency electrode describes that device is coaxial.

3. the automatically controlled generating apparatus of a kind of diffraction light-free based on electrowetting effect according to claim 1, is characterized in that, described conducting liquid is Na ₂so ₄aqueous solution, described iknsulating liquid is C ₁₂h ₂₅br.

4. the automatically controlled generating apparatus of a kind of diffraction light-free based on electrowetting effect according to claim 3, is characterized in that, described conducting liquid contain in NaCl solution, siloxane, halogenated alkane one or more.

5. the automatically controlled generating apparatus of a kind of diffraction light-free based on electrowetting effect according to claim 1, is characterized in that, hydrophobic coating is teflon.

6. the automatically controlled generating apparatus of a kind of diffraction light-free based on electrowetting effect according to claim 1, is characterized in that, described dielectric coating is polyimide or barium titanate.

7. the automatically controlled generating apparatus of a kind of diffraction light-free based on electrowetting effect according to claim 1, is characterized in that, described ring grid transparency electrode is that tin oxide mixes fluorine electro-conductive glass.

8. the automatically controlled generating apparatus of a kind of diffraction light-free based on electrowetting effect according to claim 2, it is characterized in that, described control circuit comprises power input, plurality of voltages output interface and the control module for each road magnitude of voltage of controlling plurality of voltages output interface respectively, and described plurality of voltages output interface is corresponding with each ring of ring grid transparency electrode to be connected.

9. a control method for device described in claim 1, is characterized in that, the method following steps:

(1) angle theta of the two liquid comes into contact conical interface needing control realization is determined;

(2) according to formula the magnitude of voltage U that each ring respectively in control loop grid transparency electrode applies, in formula r inclose describes the internal diameter of device, and r is the radius of each ring of ring grid transparency electrode, and △ n is the refringence of conducting liquid and iknsulating liquid, β ₀for the contact interface of conducting liquid during impressed voltage U=0 and iknsulating liquid is relative to the contact angle between hydrophobic coating, ε ₀for the permittivity of vacuum of hydrophobic coating, ε _rfor conducting liquid is relative to the relative dielectric constant of hydrophobic coating, δ ₁₂for the surface tension between conducting liquid and iknsulating liquid, d is the thickness of hydrophobic coating 3.