CN204832559U - Sheet structure capable of realizing all-dimensional full transmission of p polarized light - Google Patents

Abstract

The utility model provides a can realize all-round full transmission's of p polarized light sheet structure. The thin plate structure is a curved transparent medium plate, and light from a point light source or a linear light source can reach any point of two interfaces of the medium plate and can be incident at the Brewster angle. That is, by designing the shape curves of the two interfaces of the dielectric plate, the incident angle is exactly equal to the brewster angle when the light emitted from the light source reaches any point of the first interface. When the fully transmitted p-polarized light reaches the second interface, the angle of incidence is also the corresponding brewster angle (the brewster angles of the two interfaces are different and complementary). The utility model discloses a structure is not only simple, graceful, can realize the all-round total transmission of p polarized light moreover to greatly restrain the reflection loss of light. Due to the suppression of Fresnel reflection loss, the structure can improve the light transmission efficiency of the device and can be used for designing and manufacturing a lampshade, a lamp box and a specific optical device.

Description

A kind of thin-slab construction realizing the comprehensive total transmissivity of p polarized light

Technical field

The utility model relates to a kind of bending plate structure realizing the comprehensive total transmissivity of p polarized light.This structure can make the p polarized component of incident light all by dielectric layer, thus reduces total reflection loss.Different according to light source form, this structure can be made to embody column or rotational symmetry.This structure can be used for the designing and making of the protective cover, advertising lamp box etc. of light source.

Background technology

In lighting engineering, people have carried out a lot of research in order to the utilization ratio pursuing light source.Use business software to carry out optical numerical value simulation, people can design the structure of illuminator and size and optimize, to obtaining desirable illuminating effect.In addition, by improving the transparency of dielectric material self, people can improve the efficiency of transmission of light.Such as, utilize light to spread PC material, the transmittance of lampshade can reach 80-90% (concrete numerical value depends on the character of material self, the thickness of lampshade, shape and method of testing).

But, except the character of material self, the Fresnel reflection loss (as cover surface) of light is also the problem of Lighting Design Important.We know, will produce reflected light and refract light when light incides the interface of different materials composition.For one deck Dielectric slab, this effect is present in two interfaces of thin plate simultaneously, thus weakens the transmission capacity of light.The ratio of reflected light is decided by the contrast of incident angle, polarisation of light direction and boundary material refractive index.As far back as 1812, Scotland physicist's Brewster found, when the incident tangent of an angle of natural light equals the relative index of refraction of interfaceable media, reflection ray will for complete polarized light and polarization direction perpendicular to the plane of incidence.Now, p polarized light will produce total transmissivity, and namely the efficiency of its reflected light is 0.This phenomenon has been used to make the laser window without Fresnel loss.In the technology such as illumination, Fresnel loss (such as suppressing the reflection loss of p polarized light completely), further the raising efficiency of transmission that this effect can be utilized to suppress two, lampshade surperficial? problem is, the light that light source sends is dispersed often, is difficult to ensure that light all equals Brewster angle in the incident angle of all directions.

Summary of the invention

The technical problems to be solved in the utility model is the total transmissivity effect suppressing the Fresnel reflection in light communication process, realize p polarized light, thus provides a kind of thin-slab construction realizing the comprehensive total transmissivity of p polarized light.

The utility model solves the technical scheme that its technical matters adopts:

Realize a thin-slab construction for the comprehensive total transmissivity of p polarized light, this thin-slab construction is the dielectric-slab of curved transparent, and the refractive index of dielectric-slab is n; The incidence surface shape of described dielectric-slab meets equation: r=r ₀e ^{-n θ}, wherein r is incident angle when being θ, and light source arrives the distance of incidence surface, r ₀for light source during incidence angle θ=0 arrives the distance of incidence surface; The exit surface shape of described dielectric-slab meets equation: with wherein, r ' and θ ' reach that polar coordinates of exit surface for the refracted ray of light after incidence surface; T=t ₀e ^-θ/nfor the distance that the refracted ray of light after incidence surface passes through in dielectric-slab, t ₀for the distance passed through during incidence angle θ=0; θ _bfor Brewster angle θ _b=tan ^-1n.

Described light source adopts pointolite or line source.

Further, when light source is pointolite, described thin-slab construction is rotational symmetric shape, and when light source is line source, described thin-slab construction is column.

The utility model provides a kind of bending Dielectric slab structure, can with brewster angle incidence from the arbitrfary point at light arrival dielectric-slab two interfaces that pointolite or line source come.That is, by designing the pattern curve at dielectric-slab two interfaces, the light that light source is sent arrives the arbitrfary point place at first interface, and incident angle equals Brewster angle all just.When the p polarized light of total transmissivity arrives second interface, incident angle is equally also corresponding Brewster angle (Brewster angle at two interfaces is different, and both are remaining mutually).Structure of the present utility model is not only simple, graceful, and can realize the comprehensive total transmissivity of p polarized light, thus greatly inhibits the reflection loss of light.Due to the suppression of Fresnel reflection loss, this structure can improve the throughput of device, can be widely used in the designing and making of lampshade, lamp box and particular optical device.

Accompanying drawing explanation

Fig. 1 structure of the present utility model and light refraction schematic diagram;

The utility model thin sheet surface pattern curve figure of Fig. 2 theory calculate.

Embodiment

Embodiment of the present utility model is as follows, and the cross section curve of thin plate is provided by following equation.

Fig. 1 gives the shape of bending Dielectric slab and the refraction schematic diagram of light, and two heavy lines represent two curved surfaces of dielectric layer.Wherein, the refractive index of thin plate dielectric layer is n, and its complementary space is assumed to air.Light source is positioned at true origin O place, and incident ray OA enters dielectric layer first interface A point place refraction, and refracted ray AB reflects again at second interface B point place and outgoing.Here the two-dimensional case of first quartile is only drawn.

Make A point be any point of inside surface, its coordinate is (x, y); The angle of light OA and x-axis is θ, and the length of line segment OA is r; All the time Brewster angle θ is fixed as through the surface normal of A point and the angle of light OA _b=tan ^-1n; Be θ through the surface tangent of A point and the angle of x-axis _t(θ _t=θ+θ _b+ pi/2).Easily push away the equation at first interface is

r＝r ₀e ^-nθ(1)

Wherein r ₀for the distance of inside surface during θ=0 and light source.

Light OA obtains refracted ray AB through refraction, refract light AB be made again to produce total transmissivity, then require that AB should equal corresponding Brewster angle relative to the incident angle of outside surface.Easy proof, is now parallel to each other through the surface tangent of A, B 2 or normal direction.Make the coordinate of B point for (x', y'), its polar coordinates are (r', θ '); The angle of refracted ray AB and x-axis is θ ₁(θ ₁=θ+2 θ _b-pi/2), the length of line segment AB is t.Can be calculated

t＝t ₀e ^-θ/n(2)

Wherein t ₀for the distance that refracted ray AB during θ=0 passes through in dielectric layer.

Once incident angle θ is given, then the numerical value of r, t and the coordinate of B point also will be determined (assuming that r ₀and t ₀also selected words).Can obtain by calculating

$r^{\′}=\sqrt{r^2+t^2+2rtsin2{\mathrm{\θ}}_B}---\left(3\right)$

${\mathrm{\θ}}^{\′}=\mathrm{\θ}+\mathrm{\π}/2+{\tan }^{-1}(\frac{r}{t}\sec 2{\mathrm{\θ}}_B+tan2{\mathrm{\θ}}_B)---\left(4\right)$

Like this, the shape of second curved surface also can be decided.

Above formula (1) (2) (3) (4) are the concrete form of cross section curve equation inside and outside thin plate.

Get r ₀=100mm, t ₀the refractive index n=1.5 of=5mm, medium, Fig. 2 give the surfaces externally and internally pattern curve figure of the bending Dielectric slab of theory calculate.In this case, the incident light component (field parallel is in the plane of incidence) for arbitrary incident angle θ, p polarization all by dielectric layer, can cause omnibearing total transmissivity effect.It should be noted that, for s polarization (E-field normal is in the plane of incidence), still there is Fresnel reflection in said structure.But, due to the comprehensive total transmissivity of p polarization, the reflection loss of light obtains suppression generally.

Can with brewster angle incidence when the light that light source adopts pointolite or line source to send arrives two interfaces of thin plate, the p polarized component of incident light can produce total transmissivity on any or multiple direction of propagation.When light source is pointolite (small lamp bulb as less in size), the surface curve of two in Fig. 1 is rotated a circle around y-axis as bus, rotational symmetric thin plate dielectric layer can be obtained; When light source is line source (as thinner fluorescent tube, placing along the z-axis direction), the surface curve of two in Fig. 1 can be obtained the thin plate dielectric layer of column along z-axis translation.The dielectric layer in other region can utilize Mirror Symmetry to obtain as required.Like this, structure can work in the angular range of θ=0 ~ 180 degree or 0 ~ 360 degree.

Claims (3)

1. can realize a thin-slab construction for the comprehensive total transmissivity of p polarized light, it is characterized in that, this thin-slab construction is the dielectric-slab of curved transparent, and the refractive index of dielectric-slab is n; The incidence surface shape of described dielectric-slab meets equation: r=r ₀e ^{-n θ}, wherein r is incident angle when being θ, and light source arrives the distance of incidence surface, r ₀for light source during incidence angle θ=0 arrives the distance of incidence surface;

The exit surface shape of described dielectric-slab meets equation: with wherein, r ' and θ ' reach that polar coordinates of exit surface for the refracted ray of light after incidence surface; T=t ₀e ^-θ/nfor the distance that the refracted ray of light after incidence surface passes through in dielectric-slab, t ₀for the distance passed through during incidence angle θ=0; θ _bfor Brewster angle θ _b=tan ^-1n.

2. a kind of thin-slab construction realizing the comprehensive total transmissivity of p polarized light according to claim 1, is characterized in that, described light source adopts pointolite or line source.

3. a kind of thin-slab construction realizing the comprehensive total transmissivity of p polarized light according to claim 2, is characterized in that, when light source is pointolite, described thin-slab construction is rotational symmetric shape, and when light source is line source, described thin-slab construction is column.