CN203455546U - System generating hollow gauss beam - Google Patents

Abstract

The utility model discloses a system generating hollow gauss beams; the system is provided with a beam expander, a spatial light modulator and a vortex phase plate arranged in sequence in a light transmission direction of a light source generating linearly polarized light; the spatial light modulator is loaded with a calculation holographic raster, thereby modulating the linearly polarized light beam-expanded by the beam expander into laguerre-Gauss light beam having vortex phase, and further eliminating the vortex phase of the Laguerre-Gauss light beam through a vortex phase plate, and finally obtaining the hollow gauss beam. The system generating the hollow gauss beam can fast and conveniently generate hollow gauss beam, thereby investing the obtained hollow gauss beam into applicable a plurality of technical fields.

Description

A kind of system that produces hollow Gaussian beam

Technical field

The utility model relates to optical technical field, relates in particular a kind of system that produces hollow Gaussian beam.

Background technology

In recent years, along with widespread use and the fast development of laser technology, the using value of hollow beam has obtained paying close attention to widely and studying.

Hollow Gaussian beam is to be a kind ofly the light beam of Gaussian distribution except center remainder light intensity.Because hollow Gaussian beam has a lot of novel unique physical propertys, as barreled intensity distributions, less blackening size, propagate indeformable, there is spinning and orbit angular momentum etc., therefore hollow Gaussian beam is as laser catheter, optics signature and optics spanner, become and realized the powerful that microscopic particle is accurately controlled, thereby all had a wide range of applications scene in many-sides such as laser optics, calculation holographic, the imprison of microscopic particle optics, material science and biomedicines.

Can find out in sum, those skilled in the art are a kind of system that can produce hollow-Gaussian beam urgently, to obtain easily and fast hollow Gaussian beam, thereby the hollow Gaussian beam obtaining can be put into applicable technical field.

Utility model content

In view of this, the utility model provides a kind of system that produces hollow Gaussian beam, to realize, obtains easily and fast hollow Gaussian beam.

For achieving the above object, the utility model provides following technical scheme:

A system that produces hollow Gaussian beam, comprising:

Produce the light source of linearly polarized light;

There is certain distance with described light source, be arranged on the described polarized light direction of propagation and described linearly polarized light expanded to the beam expander of processing;

There is certain distance with described beam expander, receive the linearly polarized light after described beam expander expands and pass through the spatial light modulator that calculation holographic grating produces Laguerre-Gaussian beam;

There is certain distance with described spatial light modulator, receive described Laguerre-Gaussian beam and eliminate the vortex phase-plate of the vortex phase place of described Laguerre-Gaussian beam.

Optionally, also comprise:

Be arranged between described light source and described beam expander, regulate the optical attenuator of the luminous energy of described linearly polarized light.

Optionally, described light source is for producing the helium-neon laser of the linearly polarized light of vertical direction polarization.

Optionally, described spatial light modulator is the spatial light modulator that is loaded with computed hologram.

Optionally, the spatial light modulator that described spatial light modulator is transmission-type.

Optionally, also comprise:

Produce computed hologram, and described computed hologram is loaded in described spatial light modulator, so that described spatial light modulator forms the computing machine of calculation holographic grating.

Optionally, described vortex phase-plate is that topological charge is 2 vortex phase-plate.

Known via above-mentioned technical scheme, compared with prior art, the utility model embodiment openly provides a kind of system that produces hollow Gaussian beam, and this system sets gradually beam expander, spatial light modulator and vortex phase-plate along the light transmission direction that produces the light source of linearly polarized light.Wherein, in spatial light modulator, be loaded with calculation holographic grating, thereby the linearly polarized light after beam expander expands is modulated to the Laguerre-Gaussian beam with vortex phase place, and then by vortex phase-plate, eliminates the vortex phase place of Laguerre-Gaussian beam, obtain hollow Gaussian beam.The system of described generation hollow Gaussian beam can produce hollow Gaussian beam easily and fast, thereby the hollow Gaussian beam obtaining can be put into applicable a plurality of technical field.

Accompanying drawing explanation

In order to be illustrated more clearly in the utility model embodiment or technical scheme of the prior art, to the accompanying drawing of required use in embodiment or description of the Prior Art be briefly described below, apparently, accompanying drawing in the following describes is only embodiment of the present utility model, for those of ordinary skills, do not paying under the prerequisite of creative work, other accompanying drawing can also be provided according to the accompanying drawing providing.

Fig. 1 is the system architecture schematic diagram of the disclosed generation hollow Gaussian beam of the utility model embodiment;

Fig. 2 is the computed hologram loading in the disclosed spatial light modulator of the utility model embodiment;

Fig. 3 is the disclosed hollow Gaussian beam light distribution of the utility model embodiment circle of equal altitudes;

Fig. 4 is that disclosed another of the utility model embodiment produces the system architecture schematic diagram of hollow Gaussian beam.

Embodiment

Below in conjunction with the accompanying drawing in the utility model embodiment, the technical scheme in the utility model embodiment is clearly and completely described, obviously, described embodiment is only the utility model part embodiment, rather than whole embodiment.Embodiment based in the utility model, those of ordinary skills are not making the every other embodiment obtaining under creative work prerequisite, all belong to the scope of the utility model protection.

Fig. 1 is the system architecture schematic diagram of the disclosed generation hollow Gaussian beam of the utility model embodiment, shown in Figure 1, and the system of described generation hollow Gaussian beam can comprise:

Produce the light source 101 of linearly polarized light;

Wherein, described light source 101 can be for producing the helium-neon laser of the linearly polarized light of vertical direction polarization, thereby can produce the linearly polarized light of vertical direction polarization.

There is certain distance with described light source, be arranged on the described polarized light direction of propagation and described linearly polarized light expanded to the beam expander 102 of processing;

There is certain distance with described beam expander, receive the linearly polarized light after described beam expander expands and pass through the spatial light modulator 103 that calculation holographic grating produces Laguerre-Gaussian beam;

The linearly polarized light expanding after processing through described beam expander 102 impinges perpendicularly on spatial light modulator.Wherein, in described spatial light modulator, need to be loaded with computed hologram, to produce calculation holographic grating, generate Laguerre-Gaussian beam.Described spatial light modulator 103 can be the spatial light modulator of transmission-type.

There is certain distance with described spatial light modulator, receive described Laguerre-Gaussian beam and eliminate the vortex phase-plate 104 of the vortex phase place of described Laguerre-Gaussian beam.

The Laguerre-Gaussian beam that described spatial light modulator 103 produces is with vortex phase place, in order to obtain hollow Gaussian beam, must be by the vortex elimination of the phase in Laguerre-Gaussian beam, by described vortex phase-plate 104, eliminate after the vortex phase place of described Laguerre-Gaussian beam, obtain hollow Gaussian beam.

Wherein, the topological charge of described vortex phase-plate 104 can be 2, but the utility model embodiment is not to the restriction that fixes of the topological charge numerical value of vortex phase-plate 104, concrete, can suitable topological charge numerical value be set according to practical application scene.

In order better to understand the scheme of the present embodiment, the disclosed scheme of the present embodiment is done to clear, complete introduction below.

The light field of hollow Gaussian beam can represent with formula below:

$E_n(r,0)=G_0{\left(\frac{r^2}{{\mathrm{\ω}}_0^2}\right)}^n\exp (-\frac{r^2}{{\mathrm{\ω}}_0^2})---\left(1\right)$

Wherein, ω ₀the waist radius of light beam, G ₀a constant,

point on (x, y) xsect.For the light field above experimentally realizing, the present embodiment has proposed to adopt calculation holographic and the technology of the vortex phase place that disappears to realize the generation of hollow Gaussian beam.

Along the radiation direction that produces the light source 101 of linearly polarized light, place successively beam expander 102, spatial light modulator 103 and vortex phase-plate 104.Computed hologram is loaded in described spatial light modulator 103 and forms calculation holographic grating, when the linearly polarized light through expanding processing is irradiated in described spatial light modulator 103, computed hologram is fork like grating, its effect is exactly the PHASE DISTRIBUTION that changes incident light, thereby produces Laguerre-Gaussian beam.Fig. 2 is the computed hologram loading in the disclosed spatial light modulator of the utility model embodiment, and wherein, the density of grating can regulate by calculating parameter.The expression formula of Laguerre-Gaussian beam can be:

$E_n(r,\mathrm{\φ})=G_0{\left(\frac{r^2}{{\mathrm{\ω}}_0^2}\right)}^n\exp (-\frac{r^2}{{\mathrm{\ω}}_0^2})\exp \left(\mathrm{il\φ}\right)---\left(2\right)$

Wherein, φ is gyrobearing angle.Contrast equation (1) and (2), can find out that hollow Gaussian beam (target beam) and the Laguerre-Gaussian beam producing by spatial light modulator differ a vortex position phase exp (il φ).

Laguerre-Gaussian beam has vortex phase place.In order to eliminate vortex phase place, need in light path, insert a vortex phase-plate 104.Vortex phase-plate 104 distributes its phase structure and the phase structure of spatial light modulator 103 Laguerre-Gaussian beam out distributes on the contrary, thereby has eliminated the vortex phase place of Laguerre-Gaussian beam, obtains hollow Gaussian beam.

The vortex phase-plate transparent panel that to be a thickness deltat h be directly proportional to gyrobearing angle φ with respect to plate center.As Δ h=φ (n-1) l λ/2 π, l is integer, and λ is incident light wave length, the refractive index that n is transparent plate material.When light beam passes through such transparent panel, helical surface due to spiral phase plate, the change amount of diverse location place transmitted light beam light path is different, causes that the change of phase mass is also different, can make like this transmitted light beam produce a phase factor with vortex feature.The space structure that can calculate scroll plate according to the refractive index of material, wavelength and integer l distributes, and then under the control of exact instrument, by micro-processing, obtains finished product.If the complex amplitude of incident light is u ₀, the complex amplitude u through light beam after spiral plate can be expressed as u=u ₀exp (il φ).If l is integer, be for example 1, a vortex corrugated that spiral winding number is l just in time can be got up to form continuously in outgoing corrugated.In the present embodiment, through spatial light modulator 103 Laguerre-Gaussian beam out, be with vortex phase place, but Gaussian beam do not have vortex phase place, so the present embodiment adopts a vortex phase-plate 104 to carry out the vortex phase place of cancellation hollow Gaussian beam.By adjusting the direction of spiral phase plate, the vortex PHASE DISTRIBUTION of its generation is just mended mutually with the PHASE DISTRIBUTION of hollow Gaussian beam, then adjust the position of vortex phase-plate, so just can eliminate vortex phase place.The hollow Gaussian beam of eliminating vortex phase place can be expressed as formula (1), that is:

$E_n(r,\mathrm{\φ})=G_0{\left(\frac{r^2}{{\mathrm{\ω}}_0^2}\right)}^n\exp (-\frac{r^2}{{\mathrm{\ω}}_0^2})---\left(1\right)$

Contrast equation (1), can find out that it is hollow Gaussian beam really that this programme obtains light beam.Fig. 3 is the disclosed hollow Gaussian beam light distribution of the utility model embodiment circle of equal altitudes.

In the present embodiment, the system of described generation hollow Gaussian beam sets gradually beam expander, spatial light modulator and vortex phase-plate along the light transmission direction that produces the light source of linearly polarized light.Wherein, in spatial light modulator, be loaded with calculation holographic grating, thereby the linearly polarized light after beam expander expands is modulated to the Laguerre-Gaussian beam with vortex phase place, and then by vortex phase-plate, eliminates the vortex phase place of Laguerre-Gaussian beam, obtain hollow Gaussian beam.The system of described generation hollow Gaussian beam can produce hollow Gaussian beam easily and fast, thereby the hollow Gaussian beam obtaining can be put into applicable a plurality of technical field.

Fig. 4 is that disclosed another of the utility model embodiment produces the system architecture schematic diagram of hollow Gaussian beam, and as shown in Figure 4, the system of described generation hollow Gaussian beam can comprise:

Produce the light source 101 of linearly polarized light;

Wherein, described light source 101 can be for producing the helium-neon laser of the linearly polarized light of vertical direction polarization.

Regulate the optical attenuator 401 of the luminous energy of described linearly polarized light;

For the quality of the hollow Gaussian beam that guarantees finally to obtain, the luminous energy of the linearly polarized light that can produce described light source 101 as required be done corresponding adjusting.

There is certain distance with described light source, be arranged on the described polarized light direction of propagation and described linearly polarized light expanded to the beam expander 102 of processing;

There is certain distance with described beam expander, receive the linearly polarized light after described beam expander expands and pass through the spatial light modulator 103 that calculation holographic grating produces Laguerre-Gaussian beam;

Wherein, described spatial light modulator 103 can be for being loaded with the spatial light modulator of the transmission-type of computed hologram.

There is certain distance with described spatial light modulator, receive described Laguerre-Gaussian beam and eliminate the vortex phase-plate 104 of the vortex phase place of described Laguerre-Gaussian beam.

Wherein, the topological charge of described vortex phase-plate 104 can be 2.

In other embodiment, the system that produces hollow Gaussian beam can also comprise generation computed hologram, and described computed hologram is loaded in described spatial light modulator, so that described spatial light modulator forms the computing machine of calculation holographic grating.So also be convenient to regulate at any time by described computing machine the calculating parameter of computed hologram, to control the density degree of calculation holographic grating in described spatial light modulator, further obtain desirable Laguerre-Gaussian beam.

In the present embodiment, the system of described generation hollow Gaussian beam sets gradually optical attenuator, beam expander, spatial light modulator and vortex phase-plate along the light transmission direction that produces the light source of linearly polarized light.Wherein, in spatial light modulator, be loaded with calculation holographic grating, thereby the linearly polarized light after beam expander expands is modulated to the Laguerre-Gaussian beam with vortex phase place, and then by vortex phase-plate, eliminates the vortex phase place of Laguerre-Gaussian beam, obtain hollow Gaussian beam.The system of described generation hollow Gaussian beam can produce hollow Gaussian beam easily and fast, thereby the hollow Gaussian beam obtaining can be put into applicable a plurality of technical field.

In this instructions, each embodiment adopts the mode of going forward one by one to describe, and each embodiment stresses is the difference with other embodiment, between each embodiment identical similar part mutually referring to.

Above-mentioned explanation to the disclosed embodiments, makes professional and technical personnel in the field can realize or use the utility model.To the multiple modification of these embodiment, will be apparent for those skilled in the art, General Principle as defined herein can, in the situation that not departing from spirit or scope of the present utility model, realize in other embodiments.Therefore, the utility model will can not be restricted to these embodiment shown in this article, but will meet the widest scope consistent with principle disclosed herein and features of novelty.

Claims (7)

1. a system that produces hollow Gaussian beam, is characterized in that, comprising:

Produce the light source of linearly polarized light;

There is certain distance with described light source, be arranged on the described polarized light direction of propagation and described linearly polarized light expanded to the beam expander of processing;

There is certain distance with described beam expander, receive the linearly polarized light after described beam expander expands and pass through the spatial light modulator that calculation holographic grating produces Laguerre-Gaussian beam;

There is certain distance with described spatial light modulator, receive described Laguerre-Gaussian beam and eliminate the vortex phase-plate of the vortex phase place of described Laguerre-Gaussian beam.

2. the system of generation hollow Gaussian beam according to claim 1, is characterized in that, also comprises:

Be arranged between described light source and described beam expander, regulate the optical attenuator of the luminous energy of described linearly polarized light.

3. the system of generation hollow Gaussian beam according to claim 1, is characterized in that, described light source is for producing the helium-neon laser of the linearly polarized light of vertical direction polarization.

4. the system of generation hollow Gaussian beam according to claim 1, is characterized in that, described spatial light modulator is the spatial light modulator that is loaded with computed hologram.

5. the system of generation hollow Gaussian beam according to claim 1, is characterized in that, the spatial light modulator that described spatial light modulator is transmission-type.

6. the system of generation hollow Gaussian beam according to claim 1, is characterized in that, also comprises:

Produce computed hologram, and described computed hologram is loaded in described spatial light modulator, so that described spatial light modulator forms the computing machine of calculation holographic grating.

7. the system of generation hollow Gaussian beam according to claim 1, is characterized in that, described vortex phase-plate is that topological charge is 2 vortex phase-plate.

Images