CN1614353A - System for generating structured light with sinusoidal light intensity distribution - Google Patents

Abstract

The invention relates to a system for generating structured light with sine light intensity distribution, which comprises a coherent light source and a diffraction optical element, wherein the coherent light source is used for providing an incident light source to the diffraction optical element, the incident light source generates an interference pattern with the sine light intensity distribution after being modulated by the diffraction optical element, and the diffraction optical element is optimized and designed by utilizing a mathematical model according to the light field distribution of the incident light source on an input plane and the light field distribution of an output plane.

Description

Produce the system of the structured light of sinusoidal light intensity distributions

Technical field

The invention relates to a kind of light projection system, refer to a kind of system that is applicable to the structured light that produces sinusoidal light intensity distributions especially.

Background technology

The conoscope image of sinusoidal light intensity distributions is the projective patterns of normal use in the mechanical type interference system, is the three-dimensional appearance that can be used to measure body surface because of it.Yet this kind projective patterns also is not easy to obtain, and the volume that produces the light projector device of this kind projective patterns or relevant system is often too huge, and the light service efficiency is low.

The light projector device that produces the conoscope image of sinusoidal light intensity distributions at present is to adopt following several modes to reach: 1. utilize too graceful Green (Twyman Green) interferometer or other forms of interferometer, projected the candy strip of sinusoidal light intensity distributions by the angle that tilts.2. utilize laser, beam expander and penetration one dimension amplitude sinusoidal grating to project the candy strip of sinusoidal light intensity distributions.3. utilize projector equipment to add that black-white grating and out-of-focus projection's lens (DefocusProjection Lens) project the candy strip of sinusoidal light intensity distributions.4. utilize projector equipment to add that penetration one dimension amplitude sinusoidal grating projects the candy strip of sinusoidal light intensity distributions.

Therefore, how to provide a kind of light projector device of conoscope image of simple in structure, the sinusoidal light intensity distributions of optical efficiency is high and cost is low generation, become the problem of needing solution badly.

Summary of the invention

The objective of the invention is is providing a kind of system that produces the structured light of sinusoidal light intensity distributions, and it can provide compact, light extraction efficiency is high and can project the light projection system of the candy strip of sinusoidal light intensity distributions.

For reaching above-mentioned purpose, the present invention produces the system of the structured light of sinusoidal light intensity distributions, comprising: light modulation source together is in order to the incident light source of tool same tone to be provided; And at least one diffractive optical elements, be that modulation people having the same aspiration and interest light source makes its intensity variation conversion be sinusoidal wave Strength Changes, wherein optimizing mathematical model comprises one at least and has the relief surface of the phase type diffractive optical elements of phase modulation (PM) function, light beam input plane and light beam output plane, first wave function is at the light beam input plane, second wave function is at the light beam output plane, between first wave function and second wave function is to have transfer function, and the relation that has error function between first wave function and transfer function phase result of product and second wave function, error function sees through relief surface for people having the same aspiration and interest light source and is modulated to the conoscope image that the light beam output plane produces sinusoidal light intensity distributions via optimizing mathematical model to produce relief surface.

Wherein, this sine light intensity distributions can be represented by following mathematical expression

Wherein, I ₀Be basic light intensity item, Y is the modulate light intensity item,

Be a locus vector function, can represent with rectangular coordinates $\stackrel{\→}{r}=r(x,y,z)$ , the column type coordinate represents $\stackrel{\→}{r}=r(\mathrm{\ρ},\mathrm{\θ},z)$ Or circle coordinates is represented

Wherein, this people having the same aspiration and interest light source is to can be gas laser.

Wherein, this people having the same aspiration and interest light source can be diode laser.

Wherein, this people having the same aspiration and interest light source can be the wall emission diode laser.

Wherein, this people having the same aspiration and interest light source can be solid-state laser.

Wherein, this people having the same aspiration and interest light source can be diode group Pu solid-state laser.

Wherein, this people having the same aspiration and interest light source can be frequency multiplication or multifrequency laser.

Wherein, this people having the same aspiration and interest light source can be liquid dye laser.

Wherein, this people having the same aspiration and interest light source can be single mode or multi-mode laser.

Wherein, this diffractive optical elements can be the phase type diffractive optical elements.

Wherein, this diffractive optical elements can be amplitude formula diffractive optical elements.

Wherein, this diffractive optical elements can be phase place and the hybrid diffractive optical elements of amplitude.

Wherein, this conoscope image can be the sinusoidal light intensity distributions of linear pattern.

Wherein, this conoscope image can be circular sinusoidal light intensity distributions.

Wherein, this conoscope image can be the sinusoidal light intensity distributions of point-like.

Wherein, this conoscope image can be the sinusoidal light intensity distributions of grid point-like.

Wherein, this conoscope image can be coincidence formula

Description of drawings

For further specifying technology contents of the present invention, below in conjunction with embodiment and accompanying drawing describes in detail as after, wherein:

Fig. 1 is the configuration diagram of one embodiment of the invention.

Fig. 2 is the mathematical model synoptic diagram of the phase type diffraction element of one embodiment of the invention.

Fig. 3 is the relief surface figure of the analog result of one embodiment of the invention.

Fig. 4 is the sectional view of relief surface on X-axis of the analog result of one embodiment of the invention.

Fig. 5 is the X-axis upper section figure of the actual relief surface of one embodiment of the invention.

Fig. 6 is the conoscope image sectional view of the sinusoidal light intensity distributions on the continuous X-direction of the ideal of one embodiment of the invention.

Fig. 7 is the conoscope image sectional view that shows the sinusoidal light intensity distributions on the realistic simulation X-direction of one embodiment of the invention.

Fig. 8 is the shape synoptic diagram of conoscope image of the various sinusoidal light intensity distributions of a preferred embodiment of the present invention.

Embodiment

Relevant embodiments of the present invention, please be with reference to the system architecture synoptic diagram of Fig. 1 demonstration, it is made of people having the same aspiration and interest light source 11 and 12 two major parts of phase type diffractive optical elements, people having the same aspiration and interest light source 11 is used to provide an incident light source to phase type diffractive optical elements 12, projects the conoscope image 13 of a sinusoidal light intensity distributions via phase type diffractive optical elements 12.In present embodiment; people having the same aspiration and interest light source 11 can be gas laser, diode laser, wall emission diode laser, solid-state laser, diode group Pu solid-state laser, and laser aid such as liquid dye laser; be preferably gas laser, its kind can be frequency multiplication or multifrequency laser, single mode or multi-mode laser.Relevantly how see through the explanation that phase type diffractive optical elements 12 produces the conoscope image 13 of sinusoidal light intensity distributions, will be in following explanation in detail.Wherein, sinusoidal light intensity distributions can be represented by following mathematical expression:

I ₀Be basic light intensity item, Y is the modulate light intensity item,

Be a locus vector function, can represent with rectangular coordinates $\stackrel{\→}{r}=r(x,y,z)$ , the column type coordinate represents $\stackrel{\→}{r}=r(\mathrm{\ρ},\mathrm{\θ},z)$ Or circle coordinates is represented

Fig. 2 is the mathematical model synoptic diagram that display design produces above-mentioned phase type diffractive optical elements 12, and relevant its explanation please comprise light beam input plane 21 and light beam output plane 22 in the lump with reference to Fig. 1, and wherein, diffractive optical elements is positioned at input plane 21.This light beam input plane 21 receives the incident light source 200 that people having the same aspiration and interest light source 11 is provided, after the diffractive optical elements modulation, produce the conoscope image 13 of a sinusoidal light intensity distributions in this light beam output plane 22, wherein, the one first wave function U1 that represents this plane is arranged on the light beam input plane 21, the first wave function U1 can be expressed as U1 (x1, y1)=A (x1, y1) exp[i φ (x1, y1)]; The one second wave function U2 that represents this plane is then arranged on the light beam output plane 22, the second wave function U2 can be expressed as U2 (x2, y2)=A (x2, y2) exp[i φ (x2, y2)], and be to have a transfer function G between the first wave function U1 and the second wave function U2, the relation of transfer function G and the first wave function U1 and the second wave function U2 is to be expressed as follows:

$U2(x2,y2)=\∫G(x2,y2;x1,y1)U2(x2,y2)\mathrm{dx}1\mathrm{dy}1=\hat{G}U1$

Because above-mentioned this mathematical notation formula is the continuous integration function, therefore in order to simplify the calculated amount that reduces design, be to get N1 sampling spot at light beam input plane 21, get N2 sampling spot at light beam output plane 22, win wave function U1 and the second wave function U2 are changed into matrix form to be represented, transfer function G then becomes the matrix of one N1 * N2, and then the conversion of mathematical notation formula is as follows:

$U_{2i}=\underset{j-1}{\overset{N1}{\mathrm{\Σ}}}{G}_{\mathrm{ij}}{U}_{1j},$

Define an error function D (figure does not show) by the above-mentioned first wave function U1, the second wave function U2 and transfer function G:

$D\≡\left|\right|U2-\hat{G}U1\left|\right|$

Then behind definition error function D, be that this error function D is carried out an optimization process, relevant this optimization process is to adopt suitable optimization algorithm, as G-S algorithm, direct binary search method, simulated annealing algorithm, genetic algorithm or poplar-Gu algorithm etc.In present embodiment, adopt poplar-Gu algorithm to be optimized processing, with the relief surface of design one tool phase modulation (PM) function on phase type diffractive optical elements 12.

Fig. 3 is relief surface Figure 31 of an analog result, and it is to be positioned at above-mentioned light beam input plane, and is to be a desirable continuous design in the relief surface 31 that this manifested.Fig. 4 then is the sectional view of relief surface 31 on X-axis of Fig. 3.Fig. 5 then is the sectional view of relief surface on X-axis in the actual processing procedure, and it is to adopt three road light shields, is 8 so quantize step number.Fig. 6 is the conoscope image sectional view that shows the sinusoidal light intensity distributions on the desirable X-direction.Fig. 7 is the conoscope image sectional view of the sinusoidal light intensity distributions of display simulation result on X-direction.The different shape synoptic diagram of the conoscope image of the sinusoidal light intensity distributions that Fig. 8 then shows the present invention and throwed.See through phase type diffraction element 12, the conoscope image of the sinusoidal light intensity distributions of being throwed is to present different shapes such as linear, point-like, grid point-like, parallel wire, dotted line shape, single toroidal, concentric circles, cross-shaped or single rectangular shape, and conoscope image also can use following mathematical expression represented:

In addition, except using phase type diffraction element 12, also can use the hybrid diffractive optical elements of amplitude formula diffractive optical elements or phase place and amplitude, to reach identical or similar effects.

By above explanation as can be known, the present invention is that the sinusoidal wave optical field distribution that changes that is of the optical field distribution of the people having the same aspiration and interest light source that received with the light beam input plane and desire output designs embossment structure on the diffractive optical elements, in order to do the conoscope image that produces sinusoidal light intensity distributions for people having the same aspiration and interest light source via diffractive optical elements, to provide compact, light extraction efficiency is high and can projects the light projection system of the figure of sinusoidal light intensity distributions.

The foregoing description only is to give an example for convenience of description, and the interest field that the present invention advocated should be as the criterion so that claim is described certainly, but not only limits to the foregoing description.

Claims (18)

1. a system that produces the structured light of sinusoidal light intensity distributions is characterized in that, comprising:

Together the light modulation source is in order to the incident light source of a tool same tone to be provided; And

At least one diffractive optical elements is that this people having the same aspiration and interest light source of modulation makes its intensity variation conversion be a sinusoidal wave Strength Changes, wherein

One optimization mathematical model comprises one at least and has a relief surface of the phase type diffractive optical elements of phase modulation (PM) function, an one light beam input plane and a light beam output plane, one first wave function is at this light beam input plane, one second wave function is at this light beam output plane, be to have a transfer function between this first wave function and this second wave function, and the relation that has an error function between this first wave function and this transfer function phase result of product and this second wave function, this error function, sees through this relief surface for this people having the same aspiration and interest light source and is modulated to the conoscope image that the light beam output plane produces this sine light intensity distributions to produce this relief surface via this optimization mathematical model.

2. the system of the structured light of the sinusoidal light intensity distributions of generation as claimed in claim 1 is characterized in that, wherein, this sine light intensity distributions can be represented by following mathematical expression

Wherein, I ₀Be basic light intensity item, Y is the modulate light intensity item, Be a locus vector function, can represent with rectangular coordinates $\stackrel{\→}{r}=r(x,y,z),$ The column type coordinate is represented $\stackrel{\→}{r}=r(\mathrm{\ρ},\mathrm{\θ},z)$ Or circle coordinates is represented

3. the system of the structured light of the sinusoidal light intensity distributions of generation as claimed in claim 1 is characterized in that, wherein, this people having the same aspiration and interest light source is to can be gas laser.

4. the system of the structured light of the sinusoidal light intensity distributions of generation as claimed in claim 1 is characterized in that, wherein, this people having the same aspiration and interest light source can be diode laser.

5. the system of the structured light of the sinusoidal light intensity distributions of generation as claimed in claim 1 is characterized in that, wherein, this people having the same aspiration and interest light source can be the wall emission diode laser.

6. the system of the structured light of the sinusoidal light intensity distributions of generation as claimed in claim 1 is characterized in that, wherein, this people having the same aspiration and interest light source can be solid-state laser.

7. the system of the structured light of the sinusoidal light intensity distributions of generation as claimed in claim 1 is characterized in that, wherein, this people having the same aspiration and interest light source can be diode group Pu solid-state laser.

8. the system of the structured light of the sinusoidal light intensity distributions of generation as claimed in claim 1 is characterized in that, wherein, this people having the same aspiration and interest light source can be frequency multiplication or multifrequency laser.

9. the system of the structured light of the sinusoidal light intensity distributions of generation as claimed in claim 1 is characterized in that, wherein, this people having the same aspiration and interest light source can be liquid dye laser.

10. the system of the structured light of the sinusoidal light intensity distributions of generation as claimed in claim 1 is characterized in that, wherein, this people having the same aspiration and interest light source can be single mode or multi-mode laser.

11. the system of the structured light of the sinusoidal light intensity distributions of generation as claimed in claim 1 is characterized in that, wherein, this diffractive optical elements can be the phase type diffractive optical elements.

12. the system of the structured light of the sinusoidal light intensity distributions of generation as claimed in claim 1 is characterized in that, wherein, this diffractive optical elements can be amplitude formula diffractive optical elements.

13. the system of the structured light of the sinusoidal light intensity distributions of generation as claimed in claim 1 is characterized in that, wherein, this diffractive optical elements can be phase place and the hybrid diffractive optical elements of amplitude.

14. the system of the structured light of the sinusoidal light intensity distributions of generation as claimed in claim 1 is characterized in that, wherein, this conoscope image can be the sinusoidal light intensity distributions of linear pattern.

15. the system of the structured light of the sinusoidal light intensity distributions of generation as claimed in claim 1 is characterized in that, wherein, this conoscope image can be circular sinusoidal light intensity distributions.

16. the system of the structured light of the sinusoidal light intensity distributions of generation as claimed in claim 1 is characterized in that, wherein, this conoscope image can be the sinusoidal light intensity distributions of point-like.

17. the system of the structured light of the sinusoidal light intensity distributions of generation as claimed in claim 1 is characterized in that, wherein, this conoscope image can be the sinusoidal light intensity distributions of grid point-like.

18. the system of the structured light of the sinusoidal light intensity distributions of generation as claimed in claim 1 is characterized in that, wherein, this conoscope image can be coincidence formula

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