CN102141690A - Spiral phase plate with adjustable parameters - Google Patents

Abstract

The invention relates to a spiral phase plate with adjustable parameters, characterized in that a solid spiral phase plate is fixed on the end surface at one side of a transparent container while the spiral surface faces inwards; the container is filled with refraction rate matching liquid to form a liquid spiral phase plate complementary to the solid spiral phase plate; and the refraction rate difference between the solid spiral phase plate and the matching liquid and the topological charge value m of an optical vortex meets a relational expression in the specification. On the premise that the advantages of high conversion rate, simple light path structure, and the like of a traditional spiral phase plate are guaranteed, the spiral phase plate with the adjustable parameters, which is provided by the invention, is beneficial to simplification of the manufacture process, realization of adjustable parameters and flexible control of the topological charge value for generating the optical vortex. In addition, the spiral phase plate provided by the invention has no requirement for the wavelength of a light source and has favorable suitability.

Description

The spiral phase-plate that a kind of parameter is adjustable

Technical field

The present invention relates to a kind of spiral phase-plate of customized parameter, be used for any wavelength monochromatic source modulation is produced the optical eddy of arbitrary topology lotus, is a kind of spiral phase-plate of customized parameter according to this.

Background technology

Optical eddy in nearly decades since its unique phase structure and topological property be subjected to paying close attention to widely in fields such as fundamental research and applied researcies.At optical field, if there is the phase place singular point in the center of light wave fields, and phase place changes in the shape of a spiral continuously around this singular point, the light wave wavefront can rotate on the direction of propagation in a spiral manner, form spiral wavefront, this is very similar to the vortex phenomenon in the fluid, so this quasi-optical wave is called as " optical eddy " (OpticalVortices).Strictness is zero to the center intensity of this class light beam owing to destructive interference, and contain one that is directly proportional with gyrobearing angle θ in the PHASE DISTRIBUTION function: exp (im θ), m wherein is the topological charge of optical eddy, be illustrated in the scope of a wavelength, the Wave-front phase periodicity of optical eddy is m.

The method that produces optical eddy at present mainly contains: the laser instrument of geometric mode transformation approach, spiral phase mask plate method, transverse mode back-and-forth method, multiple beam interferometry, particular design and calculation holographic method etc.The geometric mode transformation approach requires laser beam to change the pattern of incident beam by certain optical device (as cylindrical lens etc.), obtain the corresponding modes light beam, though the method can realize very high conversion efficiency, the kind of the optical eddy that produces and difficult parameters are with control; Spiral phase mask plate method is to make around center one all thickness to change the phase mask plate of (being introduced in angle continually varying phase delay thus) continuously, plane wave is through behind this spiral phase mask plate, be equivalent to exist " spiral defective " PHASE DISTRIBUTION, its wavefront can rotate in a spiral manner around a line in the transmission direction, forms the vortex light field.Its topological charge value is determined by the vortex phase differential that mask plate causes.The vortex light field that this method produces is very regular, but the making of phase mask plate belongs to optical precision processing, and is high to processing request, and at a specific wavelength light wave, the spiral phase mask plate produces the topological charge value of optical eddy and fixes; Realized at present producing the vortex light field of Laguerre-gaussian model by the output mode of regulating laser instrument.This method is more convenient, and can obtain very strong vortex light field, but difficult parameters such as the topological charge of vortex, center are to regulate; Multiple beam interferometry is to utilize four plane waves that distribute with respect to the z rotational symmetry, the vortex array of interfering the back formation rule, this four bundles plane wave has certain restriction on phase place, be that two relative plane waves have identical initial phase, and the initial phase of four ripples can not equate simultaneously; Promptly there is the calculation holographic grating of center dislocation in the calculation holographic method with the Gaussian beam irradiation of basic mode, the diffracted beam that obtains is optical eddy, and the number of dislocation is the topological charge of optical eddy.Compare with above-mentioned several method, the calculation holographic method is widely used with its actual advantage, for example: can control the size of vortex number, vortex center, the position and the topological charge value of vortex accurately and easily, and can be by changing phase structure and the locus that the computed hologram real time altering will produce the vortex light field.Afterwards, (Spatical LightModulators SLM) made this method become convenient aspect the generation optical eddy with combining of calculation holographic to various spatial light modulators.Yet using a subject matter of calculation holographic method is to have multistage diffraction.Though can produce the optical eddy of different topology lotus simultaneously, the diffraction efficiency of each grade vortex diffraction light is all not high enough.In recent years, people are theoretical and experimentally the production method of this vortex has been done more deep research, but the diffraction efficiency that obtains is only up to 27.5%.

In addition, also have some other production method, as hollow waveguide method, rotation minute surface optical parametric oscillator method or the like, but these methods on the scope of application and range of application all not as good as above-mentioned several method.In a word, existing spiral phase mask plate has the requirement on machining accuracy height, and spiral phase mask plate and optical wavelength be one-to-one relationship, and its topological charge is non-adjustable.

Summary of the invention

The technical matters that solves

For fear of the deficiencies in the prior art part, the present invention proposes a kind of different optical wavelength and adjustable spiral phase-plate of topological charge of can be used for, and this spiral phase-plate can solve above technical matters well.

Technical scheme

The spiral phase-plate that a kind of parameter is adjustable is characterized in that comprising solid spiral phase-plate 1, index-matching fluid 2, transparent vessel 3, the bottom plane of incidence 4 and upper surface 5; Solid spiral phase-plate is fixed on the end face of transparent vessel one side, and helicoid is inside; Be full of index-matching fluid in the container, form a liquid spiral phase-plate with the complementation of solid spiral phase-plate; The topological charge value m of the refringence of described solid spiral phase-plate and matching fluid and optical eddy satisfies relational expression:

Wherein: Δ n _m=n _S-n _L, n _SBe the refractive index of solid spiral phase-plate, n _LBe the refractive index of index-matching fluid, footmark m represents the topological charge value of required optical eddy; Δ d=d _Max-d _Min, d _MaxBe the thickness in solid spiral phase-plate thickness, d _MinThickness for solid spiral phase-plate thinnest part; λ is an optical wavelength; Described solid spiral phase-plate 1 is the transparent body.

Described solid spiral phase-plate 1 adopts crown glass, and described transparent vessel 3 adopts right cylinder or rectangular parallelepiped, and is provided with filling orifice 6 on transparent vessel.

Described solid spiral phase-plate 1 adopts electro-optic crystal and adopts vertical electrooptical modulation, and transparent vessel 3 is cylinder or rectangular parallelepiped, and the outside surface of incident end face 4 and upper surface 5 is covered with first transparency electrode 7 and second transparency electrode 8 respectively.

Described solid spiral phase-plate 1 adopts electro-optic crystal and adopts the transverse electric optical modulation, and transparent vessel 3 is a rectangular parallelepiped, and first opaque electrode 9 and second opaque electrode 10 are in two relative sides of rectangular parallelepiped.

The inner chamber height of solid spiral phase-plate and cylindricality transparent vessel is D among the present invention, and the thickness in solid spiral phase-plate thickness is d _Max, thinnest part is d _Min, then the thickness of corresponding position index-matching fluid is respectively (D-d _Max) and (D-d _Min).The refractive index of described solid spiral phase-plate is n _S, the refractive index of described matching fluid is n _L, the two refractive indices n=n _S-n _L, the two thickness difference Δ d=d _Max-d _MinWhen a branch of wavelength is the plane light wave of λ during from the surface feeding sputtering of cylindricality transparent vessel, the phase of light wave in solid spiral phase-plate thickness postpone be

${\mathrm{\Φ}}_{\max }=\frac{2\mathrm{\π}}{\mathrm{\λ}}[n_S{d}_{\max }+n_L(D-d_{\max })]=\frac{2\mathrm{\π}}{\mathrm{\λ}}[(n_S-n_L)d_{\max }+n_{L}D]---\left(1\right)$

The phase of light wave of solid spiral phase-plate thinnest part postpones

${\mathrm{\Φ}}_{\min }=\frac{2\mathrm{\π}}{\mathrm{\λ}}[n_S{d}_{\min }+n_L(D-d_{\min })]=\frac{2\mathrm{\π}}{\mathrm{\λ}}[(n_S-n_L)d_{\min }+n_{L}D]---\left(2\right)$

The thickest and phase differential thinnest part is

$\mathrm{\Δ\Φ}={\mathrm{\Φ}}_{\max }-{\mathrm{\Φ}}_{\min }=\frac{2\mathrm{\π}}{\mathrm{\λ}}\mathrm{\Δn\Δd}---\left(3\right)$

This shows: when the refractive index n of index-matching fluid _LRefractive index n with solid spiral phase-plate _SWhen identical, promptly during Δ n=0, the present invention produces uniform phase delay to the light wave of process, no modulating action.Refractive index n when index-matching fluid _LRefractive index n with solid spiral phase-plate _SNot not simultaneously, i.e. Δ n ≠ 0 o'clock, the spiral phase differential ΔΦ that the present invention produces is determined by (3) formula.At this moment, when a branch of wavelength is the surface feeding sputtering of the monochromatic plane light wave of λ from the cylindricality transparent vessel, the wavefront of its transmitted light will have the spiral phase structure, form the vortex light beam, its topological charge value

Under the laser beam irradiation of setted wavelength, when the Δ d value of design is big, only need a very little Δ n can produce enough big topological charge value, and (be the refractive index n of index-matching fluid by controlling the positive and negative of Δ n _LRefractive index n with solid spiral phase-plate _SRelative size) be the positive and negative of may command topological charge.For example: Δ d=0.1mm, optical wavelength λ=500nm will export topological charge and be 1 optical eddy, and the refractive index difference that needs only is

When needs obtained topological charge for-1 optical eddy, only need regulate refractive index difference was Δ n _-1=-0.005.When refractive index difference is

The time, the optical eddy topological charge of output is 2; Equally, as Δ n _-2=-0.01 o'clock is-2 optical eddy with the output topological charge.By that analogy, if will obtain the optical eddy that topological charge is m, only need the adjusting refractive index difference to be

$\mathrm{\Δ}{n}_m=\frac{\mathrm{m\λ}}{\mathrm{\Δd}}---\left(4\right)$

This shows, by the refractive indices n of control index-matching fluid and solid spiral phase-plate, but the parameter of the present invention's free adjustment spiral phase-plate, at the topological charge value of any optical wavelength light wave control optical eddy.The control of refringence can change liquid refractivity by electrooptical effect, magneto-optic effect and current effect.Also can adopt the refractive index by electrooptical effect control solid such as electro-optic crystal.

Beneficial effect

The adjustable spiral phase-plate of a kind of parameter that the present invention proposes, can guarantee existing spiral phase-plate such as conversion efficiency height, under the prerequisite of advantage such as light channel structure is simple, simplify manufacture craft, and realize that parameter is adjustable, can control the topological charge value that produces optical eddy flexibly.In addition, the present invention does not require optical source wavelength, has excellent adaptability.

Description of drawings

One, Fig. 1-a to Fig. 2-b is apparatus of the present invention structural representation one, wherein:

Fig. 1-a is the profile sketch.

Fig. 1-b is the sectional view on A-A plane among Fig. 1-a.

Fig. 2-a is the front view of solid spiral phase-plate among Fig. 1-b.

Fig. 2-b is the vertical view of solid spiral phase-plate among Fig. 1-b.

Wherein: 1, transparent solid spiral phase-plate; 2, index-matching fluid; 3, cylindrical transparent containers; 4, the bottom plane of incidence; 5, upper surface; 6, index-matching fluid filling orifice.

Two, Fig. 3-a to Fig. 4-b is apparatus of the present invention structural representation two, wherein:

Fig. 3-a is the profile sketch.

Fig. 3-b is the sectional view on A-A plane among Fig. 3-a.

Fig. 4-a is the front view of solid spiral phase-plate among Fig. 3-b.

Fig. 4-b is the vertical view of solid spiral phase-plate among Fig. 3-b.

Wherein: 1, transparent solid spiral phase-plate; 2, index-matching fluid; 3, cylindrical transparent containers; 4, the bottom plane of incidence; 5, upper surface; 7, the first transparent electroplax; 8, the second transparent electroplax.

Three, Fig. 5-a to 6-b is apparatus of the present invention structural representation three, wherein:

Fig. 5-a is the profile sketch.

Fig. 5-b is the sectional view on A-A plane among Fig. 5-a.

Fig. 6-a is the front view of solid spiral phase-plate among Fig. 5-b.

Fig. 6-b is the vertical view of solid spiral phase-plate among Fig. 5-b.

Wherein: 1, square transparent solid spiral phase-plate; 2, index-matching fluid; 3, cuboid container; 4, the bottom plane of incidence; 5, upper surface; 9, first opaque electrode; 10, second opaque electrode.

Embodiment

Now in conjunction with the embodiments, accompanying drawing is further described the present invention:

Embodiment one:

Consult Fig. 1-a to Fig. 2-b.Present embodiment comprises transparent solid spiral phase-plate 1 (by thick left-handed to approaching), index-matching fluid 2, cylindricality transparent vessel 3.The baseplane of solid spiral phase-plate 1 is close to the bottom plane of incidence 4 of cylindricality transparent vessel 3.Be full of index-matching fluid 2 in the upper surface 5 of cylindricality transparent vessel 3 and the cavity between the spiral phase-plate 1.Side at cylindrical container has matching fluid filling orifice 6.In the present embodiment, need select the matching fluid of different refractivity in advance, and inject by filling orifice 6.Solid spiral phase-plate is made by transparent material, is example with the crown glass in the present embodiment, makes the solid spiral phase-plate of thickness difference Δ d=0.02mm.Under the irradiation of 632nm wavelength laser, the crown glass refractive index is n _S=1.520; Present existing index-matching fluid can provide n _L=1.300～1.700 adjustable extent, precision reach ± and 0.0002.Export topological charge and be 1 optical eddy, the refractive index difference that needs is

$\mathrm{\&Delta;}{\mathrm{<figure-callout\; id="1"\; label="n"\; filenames="HSA00000488447500012.png,HSA00000488447500034.png"\; state="\{\{state\}\}">n</figure-callout>}}_1=\frac{\mathrm{\&lambda;}}{\mathrm{\&Delta;d}}=\frac{0.632}{30}=0.0316---\left(5\right)$

If will obtain the optical eddy that topological charge is m, only needing to regulate refractive index difference is Δ n=n _S-n _Lm=m Δ n ₁, that is to say that index-matching fluid need satisfy

n _Lm＝n _S-mΔn ₁＝1.520-m0.0316 (6)

N wherein _LmBe and obtain the matching fluid refractive index that topological charge is the optical eddy needs of m.When selecting different wave length laser for use, only need know the refractive index value of solid spiral phase-plate under this wavelength, just can similarly obtain the relation of matching fluid refractive index and optical eddy topological charge.In addition, the difference in height Δ d that suitably reduces solid spiral phase-plate 1 can reduce the accuracy requirement of refractive index matching fluid.

In use, at first select the refractive index of matching fluid, inject and be full of the cavity of cylindricality transparent vessel by hole 6 according to formula (6).Use the bottom plane of incidence 4 of wavelength then, be the optical eddy that has the particular topology lotus at the light beam of the upper surface of device 5 outgoing as 632nm laser beam vertical irradiation cylindricality transparent vessel 3.For example: when the matching fluid refractive index n _L=1.4568 o'clock, the optical eddy topological charge was 2, works as n _L=1.6148 o'clock, the optical eddy topological charge was-3.It should be noted that when laser beam and during 5 incidents, will behind bottom face 4, obtain having the optical eddy of opposite topological charge from the upper surface.As n _L=1.4568 o'clock, the optical eddy topological charge was-2, works as n _L=1.6148 o'clock, the optical eddy topological charge was 3.

Embodiment two:

Consult Fig. 3-a to Fig. 4-b.Present embodiment comprises transparent solid spiral phase-plate 1 (by thick left-handed to approaching), index-matching fluid 2, cylindrical transparent containers 3.The incident end face 4 of cylindrical container and the outside surface of upper surface 5 are covered with transparency electrode 7 and 8 respectively.The bottom plane of incidence 4 of cylindricality transparent vessel 3 is close in the baseplane of solid spiral phase-plate 1.Be full of index-matching fluid 2 in the upper surface 5 of cylindricality transparent vessel 3 and the cavity between the spiral phase-plate 1.Transparent solid spiral phase-plate 1 is made by electro-optic crystal, and one of its electric field induction dielectric main shaft (being designated as z ' axle) points to the top perpendicular to the bottom surface of phase-plate, and parallel with incident beam, the applied field direction is parallel to z ' axle, promptly adopts vertical electrooptical modulation.Incident light is a linearly polarized light, and one of two other induction dielectric main shaft of its polarization direction and electro-optic crystal (be designated as x ' and y ', as shown in Figure 4) parallel.The specific inductive capacity of index-matching fluid is identical at the specific inductive capacity of z ' direction of principal axis (direction of an electric field) with electro-optic crystal, therefore can eliminate the crooked and sudden change of electric field at both interfaces, when between first transparency electrode 7 and second transparency electrode 8, adding voltage, will produce uniform electric field in this device.With symmetry be

Electro-optic crystal (as the KDP crystal) using method of this device is described for example.

Under certain specified temp and wavelength condition, along crystal z direction of principal axis added electric field.The z axle is

The optical axis of crystal, corresponding induction major axes orientation constant (being that z ' axle overlaps with the z axle) behind the added electric field, corresponding electrooptical coefficient is r ₆₃The principal refractive index of crystal is respectively n _oAnd n _e, z axle specific inductive capacity is ε.The specific inductive capacity of index-matching fluid is all ε under uniform temp and the wavelength condition, and refractive index is n _LMaking alive U between transparent first transparency electrode 7 and second transparency electrode 8 is then along the axial electric field of z

$E_z=\frac{U}{\mathrm{\&epsiv;D}}---\left(7\right)$

Wherein D is a distance (thickness of ignoring bottom face 4 and upper surface 5) between two electrodes.According to The electro-optical characteristic of the crystal refractive index on x ' axle and the y ' axle as can be known is respectively

$n_{x^{\&prime;}}=n_o+\frac{n_o^3}{2}{r}_{63}{E}_z=n_o+\frac{n_o^3{r}_{63}}{2\mathrm{\&epsiv;D}}U---\left(8\right)$

$n_{y^{\&prime;}}=n_o+\frac{n_o^3}{2}{r}_{63}{E}_z=n_o-\frac{n_o^3{r}_{63}}{2\mathrm{\&epsiv;D}}U---\left(9\right)$

Be parallel to the situation of x ' axle for the polarization direction of incident laser, the refringence of solid spiral phase-plate 1 and index-matching fluid 2 is

$\mathrm{\&Delta;n}=n_S-n_L=n_{x^{\&prime;}}-n_L=n_o+\frac{n_o^3{r}_{63}}{2\mathrm{\&epsiv;D}}U-n_L---\left(10\right)$

Arrangement (10) formula gets

$U=(\mathrm{\&Delta;n}+n_L-n_o)\frac{2\mathrm{\&epsiv;D}}{n_o^3{r}_{63}}---\left(11\right)$

According to formula (4), when the thickness difference of solid spiral phase-plate is Δ d, export the optical eddy that topological charge is m, the refractive index difference that needs is

Voltage should be between the electrode at this moment

$U_m=(\frac{\mathrm{m\&lambda;}}{\mathrm{\&Delta;d}}+n_L-n_o)\frac{2\mathrm{\&epsiv;D}}{n_o^3{r}_{63}}---\left(12\right)$

Therefore, in the present embodiment, be parallel to the bottom plane of incidence 4 of the laser beam irradiation device of x ' axle with the polarization direction, and regulate voltage between first transparency electrode 7 and second transparency electrode 8 according to formula (12), outgoing beam is the optical eddy that topological charge is m.In addition, when the polarization direction of incoming laser beam was parallel to y ' axle, equally by formula (12) regulated the voltage between the transparency electrode 7,8, will obtain the optical eddy of topological charge for-m.

Embodiment three:

Consult Fig. 5-a to 6-b.Present embodiment comprise transparent solid spiral phase-plate 1 (rectangular parallelepiped, bottom surface are that the length of side is the square of l, spiral part by thick to thin left-handed, as shown in Figure 6), index-matching fluid 2, cuboid container 3.The baseplane of solid spiral phase-plate 1 is close to the bottom plane of incidence 4 of square container 3.Be full of index-matching fluid 2 in the upper surface 5 of square container 3 and the cavity between the spiral phase-plate 1.The outside surface of the two opposite side surfaces of cuboid container 3 is covered with first opaque electrode 9 and second opaque electrode 10 respectively.Transparent solid spiral phase-plate 1 is made by electro-optic crystal, and one of its electric field induction dielectric main shaft (being designated as z ' axle) is parallel to the bottom surface of phase-plate, and perpendicular to incident beam, the applied field direction promptly adopts the transverse electric optical modulation along z ' axle.Two other induction dielectric main shaft is designated as x ' and y ' axle respectively, wherein x ' axle be parallel to the bottom surface of phase-plate and y ' axle perpendicular to bottom surface sensing direction of beam propagation.Incident light is a linearly polarized light, and its polarization direction is parallel to x ' axle, perpendicular to z ' axle.The specific inductive capacity of index-matching fluid is identical with the specific inductive capacity of electro-optic crystal z ' direction of principal axis (direction of an electric field), therefore can eliminate the crooked and sudden change of electric field at both interfaces, when between first opaque electrode 9 and second opaque electrode 10, adding voltage, will produce horizontal uniform electric field in this device.With symmetry be

Electro-optic crystal (as the KDP crystal) using method of this device is described for example.

Under certain specified temp and wavelength condition, along crystal z direction of principal axis added electric field.The z axle is

The optical axis of crystal, corresponding induction major axes orientation constant (be z ' axle with z axle with overlap) behind the added electric field, the electrooptical coefficient of correspondence is r ₆₃The principal refractive index of crystal is respectively n _oAnd n _e, z axle specific inductive capacity is ε.The specific inductive capacity of index-matching fluid should be ε under uniform temp and the wavelength condition, and refractive index is n _LMaking alive U between first opaque electrode 9 and second opaque electrode 10 is then along the axial electric field of z

$E_z=\frac{U}{\mathrm{\&epsiv;l}}---\left(13\right)$

Wherein l is a distance (ignoring the square container wall thickness) between two electrodes.According to

The electro-optical characteristic of the crystal refractive index on x ' axle as can be known is

$n_{x^{\&prime;}}=n_o+\frac{{\mathrm{<figure-callout\; id="3"\; label="n\; o"\; filenames="HSA00000488447500011.png,HSA00000488447500021.png"\; state="\{\{state\}\}">n</figure-callout>}}_o^{}}{2}{r}_{63}{E}_z=n_o+\frac{n_o^3{r}_{63}}{2\mathrm{\&epsiv;l}}U---\left(14\right)$

For the incoming laser beam that the polarization direction is parallel to x ' axle, the refringence of solid spiral phase-plate 1 and index-matching fluid 2 is

$\mathrm{\&Delta;n}=n_S-n_L=n_{x^{\&prime;}}-n_L=n_o+\frac{n_o^3{r}_{63}}{2\mathrm{\&epsiv;l}}U-n_L---\left(15\right)$

Arrangement (15) formula gets

$U=(\mathrm{\&Delta;n}+n_L-n_o)\frac{2\mathrm{\&epsiv;l}}{n_o^3{r}_{63}}---\left(16\right)$

According to formula (4), when the thickness difference of solid spiral phase-plate is Δ d, export the optical eddy that topological charge is m, the refractive index difference that needs is

Voltage should be between the electrode at this moment

$U_m=(\frac{\mathrm{m\&lambda;}}{\mathrm{\&Delta;d}}+n_L-n_o)\frac{2\mathrm{\&epsiv;l}}{n_o^3{r}_{63}}---\left(17\right)$

Therefore, in the present embodiment, be parallel to the bottom plane of incidence 4 of the laser beam irradiation device of x ' axle with the polarization direction, and regulate voltage between first opaque electrode 9 and second opaque electrode 10 according to formula (17), outgoing beam is the optical eddy that topological charge is m.

Claims (4)

1. spiral phase-plate that parameter is adjustable is characterized in that comprising solid spiral phase-plate (1), index-matching fluid (2), transparent vessel (3), the bottom plane of incidence (4) and upper surface (5); Solid spiral phase-plate is fixed on the end face of cylindricality transparent vessel one side, and helicoid is inside; Be full of index-matching fluid in the container, form a liquid spiral phase-plate with the complementation of solid spiral phase-plate; The topological charge value m of the refringence of described solid spiral phase-plate and matching fluid and optical eddy satisfies relational expression:

Wherein: Δ n _m=n _S-n _L, n _SBe the refractive index of solid spiral phase-plate, n _LBe the refractive index of index-matching fluid, footmark m represents the topological charge value of required optical eddy; Δ d=d _Max-d _Min, d _MaxBe the thickness in solid spiral phase-plate thickness, d _MinThickness for solid spiral phase-plate thinnest part; λ is an optical wavelength; Described solid spiral phase-plate (1) is the transparent body.

2. the spiral phase-plate adjustable according to the described parameter of claim 1 is characterized in that: described solid spiral phase-plate (1) adopts crown glass, and described transparent vessel (3) adopts right cylinder or rectangular parallelepiped, and is provided with filling orifice (6) on transparent vessel.

3. the spiral phase-plate adjustable according to the described parameter of claim 1, it is characterized in that: described solid spiral phase-plate (1) adopts electro-optic crystal and adopts vertical electrooptical modulation, transparent vessel (3) is cylinder or rectangular parallelepiped, and the outside surface of incident end face (4) and upper surface (5) is covered with first transparency electrode (7) and second transparency electrode (8) respectively.

4. the spiral phase-plate adjustable according to the described parameter of claim 1, it is characterized in that: described solid spiral phase-plate (1) adopts electro-optic crystal and adopts the transverse electric optical modulation, transparent vessel (3) is a rectangular parallelepiped, and first opaque electrode (9) and second opaque electrode (10) are in two relative sides of rectangular parallelepiped.

Images