CN203773077U - LED lens capable of generating single bottle beam - Google Patents

Abstract

The utility model discloses an LED lens capable of generating a single bottle beam. The LED lens comprises a lens body in an ellipsoidal shape. One end of the lens body in the long axis direction thereof presents a flat shape and a circular cross section vertical to the long axis of the lens body is formed. The center of the circular cross section comprises an inwardly-recessed spherical surface used as an incidence surface. An LED light source is arranged at the spherical center of the inwardly-recessed spherical surface. The outline curved surface of the lens body is an exitance surface which comprises a central part and a peripheral part. The central part and the peripheral part generate two conical waves with different conical angles. The two conical waves are respectively coherent and superposed to form two similar Bessel beams. The bottle beam is generated between the two similar Bessel beams. Compared with a product generating the bottle beam by using other methods, the LED lens obtains a single bottle beam with a single element, and is easy in element processing, high in transformation efficiency, simple in structure, and low in cost.

Description

A kind of LED lens that produce single bottle beams

Technical field

The utility model relates to a kind of LED lens that can produce single bottle beams (Bottle beam) using light emitting diode (LED) as light source, can be used for producing hollow beam, catch and manipulate particulate as light tweezer, there is high using value at the aspect such as particle confinement, atom cooling, also can be used for the aspects such as scientific research.

Background technology

Bottle beams (Bottle beam) be a branch of be the light beam of zero three-dimensional closed area along there being intensity on optical propagation direction, around round high-intensity light.Bottle beam can be used as the powerful such as light tweezer and optics spanner, also can be used for imprisoning microscopic particle, neutral atom, molecule and biological cell etc., in life science and nanosecond science and technology field, has important application.

Tradition produces Bottle beam and adopts the high laser of coherence as light source.But the Bottle beam that incoherent light source produces has the advantages such as Wave-front phase is difficult for distorting, light distribution is more even, has high using value for particle confinement, atom cooling etc.

Utility model content

The purpose of this utility model is to provide a kind of LED lens that produce single bottle beams, it adopts incoherent light source LED to produce Bottle beam, just can directly obtain single Bottle beam by single element, there is conversion efficiency high, cost is low, advantage simple in structure, element processing is relatively easy, cost is low.

To achieve these goals, the utility model adopts following technical scheme:

A kind of LED lens that produce single bottle beams, there is the lens body of quasi-ellipsoid shape, the Length Ratio of its major axis and minor axis is 10-11:2-3, this lens body is truncation shape along of its long axis direction, form the circular transverse cross-sectional of a major axis perpendicular to lens body, the middle part of this circular transverse cross-sectional has the interior concave spherical surface as the plane of incidence, the sphere center position of this interior concave spherical surface therewith home position of circular transverse cross-sectional overlaps, LED light source correspondence is positioned over the sphere center position of concave spherical surface in this, and the outline curved surface of this lens body is exit facet.

Described exit facet is divided into two parts, the center section that deflection angle to incident ray of the major axis of close described lens body is larger and the less periphery of the deflection angle to incident ray around this center section of encirclement.

Taking any point of described center section and the line of described sphere center position as incident ray, Jia Jiao≤45 ° of the major axis of this incident ray and described lens body.

Said lens body is PMMA lens.

Adopt after such scheme, the utility model can produce the LED lens of single bottle beams, the plane of incidence of lens is sphere, LED light source is placed on the centre of sphere place of this sphere, light direction of propagation after this sphere is constant, light after exit facet by exit facet being divided into two parts to the difference of deflection of light ability, near the center section of lens body major axis with around the periphery that surrounds center section, light is after center section, deflection angle is larger, is irradiated on objective plane the absolute value of coordinate larger; Light is after periphery, and deflection angle is less, is irradiated on objective plane the absolute value of coordinate less.Center section and periphery will produce the conical wave of two bundle different cone angle, and two bundle conical waves coherence stack respectively forms the approximate Bezier light of two bundles, between the approximate Bezier light of two bundles, has occurred a region that does not have light to pass through, i.e. Bottle beam.Regulating the coordinate figure of light beam irradiates on objective plane is the size of adjustable Bottle beam.

The utility model has the advantage of by single element and can directly obtain single Bottle beam, conversion efficiency is high, cost is low, simple in structure, element processing is relatively easy, and LED as the novel incoherent light source of one have that volume is little, power consumption is low, the life-span is long, high brightness is low in calories, sturdy and durable, the cost that produces Bottle beam is reduced greatly.The utility model provides a kind of new method of succinct practicality for obtaining Bottle beam.

Brief description of the drawings

Fig. 1 is the exit facet resolution principle figure of lens in the utility model.

Fig. 2 is the light path schematic diagram that in the utility model, lens produce Bottle beam.

Fig. 3 is the bus figure of lens in the utility model.

Fig. 4 is the stereographic map of lens in the utility model.

Fig. 5 is the stereographic map of another angle of lens in the utility model.

Embodiment

Below in conjunction with accompanying drawing and example, structure and the principle to the utility model New LED lens done the detailed explanation of a nearly step.

A kind of LED lens that produce single bottle beams of the present utility model, as in Figure 3-5, there is the lens body 100 that the PMMA material of quasi-ellipsoid shape is made, the major axis of lens body 100 and the Length Ratio of minor axis are 10-11:2-3, this lens body 100 is truncation shape along of its long axis direction, form the circular transverse cross-sectional 11 of a major axis perpendicular to spheroid, the middle part of this circular transverse cross-sectional 11 has the interior concave spherical surface 111 as the plane of incidence, the sphere center position of this interior concave spherical surface 111 therewith home position of circular transverse cross-sectional 11 overlaps, LED light source correspondence is positioned over the sphere center position of concave spherical surface 111 in this, the outline curved surface 12 of this lens body 100 is exit facet.This exit facet is divided into two parts, the center section that deflection angle to incident ray of the major axis 13 of close lens body 100 is larger and the less periphery of the deflection angle to incident ray around this center section of encirclement.Taking any point of this center section and the line of described sphere center position as incident ray, Jia Jiao≤45 ° of the major axis 13 of this incident ray and lens body.

As shown in Figure 1, set up rectangular coordinate system taking light source position as initial point, taking the wafer place plane of LED light source, as XY plane, (wherein Y-axis is perpendicular to XZ place plane, perpendicular to paper, therefore, in figure, Y-axis does not mark), vertical wafer in-plane is Z axis. taking XZ place plane as example, h is the distance of objective plane and light source. the intersection point of incident ray and lens exit facet is A, and coordinate is (x, z), the intersection point of emergent ray and objective plane is B, coordinate is (r, h), can obtain:

The unit vector of incident ray: $\stackrel{\→}{\mathrm{in}}=\frac{1}{\sqrt{x^2+z^2}}(x,z)---\left(1\right)$ The unit vector of emergent ray: $\stackrel{\→}{\mathrm{out}}=\frac{1}{\sqrt{{(r-x)}^2+{(h-z)}^2}}(r-x,h-z)---\left(2\right)$

In 1/4th exit facets shown in Fig. 1 by the angle m decile in (0, pi/2), corresponding to incident ray i ₀-i _mwith the angle of Z axis be θ ₀-θ _m, after the refraction of lens exit facet, θ ₀-θ _m/2point: x=-r on objective plane shown in corresponding diagram 2 ₂, θ _m/2-θ _mpoint on corresponding objective plane: x=-r ₁.

If initial light i ₀along Z axis forward, on its travel path, select an initial point S ₀(0, Z ₀) as the starting point of exit facet, i ₀after exit facet refraction corresponding to the some H (r in target face ₂, h), by this coordinate of 2, by formula (1), (2) can obtain the unit vector of initial light incident direction and exit direction.Can obtain free form surface at initial point S by refraction law ₀the normal vector at place:

$\stackrel{\→}{N_0}=n\·\stackrel{\→}{{\mathrm{in}}_0}-\stackrel{\→}{{\mathrm{out}}_0}---\left(3\right)$

N is the refractive index of lens material, obtains S by normal vector and starting point coordinate ₀the section T of point ₀.

Obtain light i ₁with section T ₀point of intersection S ₁(X ₁, Z ₁), and by the corresponding point H (r on objective plane ₂, h) obtain a S ₁the incident ray at place and the unit vector of emergent ray obtain at S according to (3) formula again ₁the normal vector that point is surperficial by normal vector and S ₁the coordinate of point is obtained section T ₁, then obtain light i ₂with section T ₁point of intersection S ₂(X ₂, Z ₂), according to above-mentioned steps, iteration is obtained the discrete data point S of lens exit facet on XZ the section curve ₀, S ₁... S _mcoordinate, determined the transversal of lens exit facet in XZ plane. in iterative process, angle bisecting is less, and result of calculation and re-set target are more approaching, and error is less.

As shown in Figure 2, be divided into four parts after being positioned at light that LED pointolite that O orders the sends exit facet through lens body, tetrameric light beam is focused on respectively from x=r on the objective plane at a certain distance h of lens place ₁, r ₂,-r ₁,-r ₂place.AB on the exit facet of the light scioptics body that wherein LED sends ₁section (OB ₁with approximately 45 ° of the angles of Z axis, AB ₁section is center section) after converge at x=-r on objective plane ₂place, deflection angle is larger.B on the exit facet of lens body ₂after C section (periphery), converge at x=-r on objective plane ₁place, deflection angle is less.And the exit facet of lens body is about Z axis Rotational Symmetry, therefore the zone line intersecting at this four segment beam, can produce one and there is no the region that light passes through (in Fig. 2 shown in the PQRS of shadow region), thereby form bottle beams, be Bottle beam. (terminal A P in the region at the two ends of Bottle beam, the quadrilateral area that RT is folded), there are respectively two conical waves superimposed, form approximate non-diffraction Bessel beam.The start position of Bottle beam is Fig. 2 middle conductor B ₁the intersection point P of H and Z axis, final position is line segment B ₂the intersection point R of G and Z axis, the dark territory maximum radius location of Bottle beam and maximum dark territory radius can be by line segment D ₁e and B ₂the intersection point Q of G calculates.Adjusting the coordinate position of light beam irradiates on objective plane is the size of capable of regulating Bottle beam.

Claims (4)

1. one kind can produce the LED lens of single bottle beams, it is characterized in that: the lens body with quasi-ellipsoid shape, the Length Ratio of its major axis and minor axis is 10-11:2-3, this lens body is truncation shape along of its long axis direction, form the circular transverse cross-sectional of a major axis perpendicular to lens body, the middle part of this circular transverse cross-sectional has the interior concave spherical surface as the plane of incidence, the sphere center position of this interior concave spherical surface therewith home position of circular transverse cross-sectional overlaps, LED light source correspondence is positioned over the sphere center position of concave spherical surface in this, the outline curved surface of this lens body is exit facet.

2. a kind of LED lens that produce single bottle beams according to claim 1, it is characterized in that: described exit facet is divided into two parts the center section that deflection angle to incident ray of the major axis of close described lens body is larger and the less periphery of the deflection angle to incident ray around this center section of encirclement.

3. a kind of LED lens that produce single bottle beams according to claim 2, it is characterized in that: taking any point of described center section and the line of described sphere center position as incident ray, Jia Jiao≤45 ° of the major axis of this incident ray and described lens body.

4. according to a kind of LED lens that produce single bottle beams described in claim 1-3 any one, it is characterized in that: said lens body is PMMA lens.