CN105240735A - Parallel light source - Google Patents

Abstract

The invention discloses a parallel light source which comprises a light-emitting element and a light-permeable panel. Light rays emitted by the light-emitting element pass through the light-permeable panel and are converted into parallel light. Birefringent crystals are arranged inside the light-permeable panel regularly. The dimension of the birefringent crystals is the wavelength magnitude of the light rays emitted by the light-emitting element. By means of the parallel light source, the problem that in the prior art, a parallel light source is prone to being diffused is solved, an artificial parallel light source with the larger diameter can be provided, the condition of parallel illumination of sunlight in the natural environment can be simulated perfectly, and the parallel light source has great significance on the development of solar photovoltaic products.

Description

A kind of source of parallel light

Technical field

The present invention relates to artificial directional light in optical field.It is widely used in photocatalysis, Industrial Catalysis, photodissociation aquatic products hydrogen, photochemical catalysis, photochemical syntheses, light degradation pollutant, water pollutions process, biological illumination, the research fields such as optical detection, condensation photovoltaic, acceleration by light experiment.

Background technology

Solar energy have the restriction of clean, No Assets region, concerning the mankind forever without good characteristics such as exhaustions, be more and more subject to the favor of people, wherein solar energy photovoltaic utilization and the sunshine technology that is directly changed into electric energy by photovoltaic device is especially noticeable.

At present, a complete light gathering photovoltaic power generating system mainly comprises several parts such as photovoltaic concentrator module, sun tracker, power storage or contravariant equipment.Photovoltaic concentrator module, as photoelectric conversion part, formed with the circuit board being provided with photovoltaic battery wafers primarily of transmission-type or reflection-type beam condenser.Collector lens is made substantially just to sunniness direction by sun tracker during use, then respectively sunshine converged by these collector lenses and project on the receiving plane of photovoltaic battery wafers corresponding with each collector lens on circuit board, thus making generation current in each photovoltaic battery wafers, these electric currents are exported by the circuit on circuit board.

The photovoltaic concentrator module disclosed in Chinese patent application file that publication number is CN101640502A has representativeness.The point light-focusing Fresnel lens adopted in this battery component has become the first-selection of the collector lens that industry is generally acknowledged.In addition also have many disclosing to adopt light-focusing Fresnel lens to make the bibliography of the concentrating photovoltaic power generation technology of collector lens, do not repeat them here.

Condensation photovoltaic, when testing, needs a kind of source of parallel light, in order to simulated solar irradiation, but is difficult to the good source of parallel light of acquisition one in the lab at present.Its reason is that current source of parallel light bright dipping bore is difficult to do greatly, and general light source bore is only when φ about 100mm, and the usual angle of divergence has reached 5 degree.If strengthen light source bore further, its angle of divergence also can increase further.Even if the angle of divergence controlled at about 5 °, artificial light sources is also difficult to the sunshine parallel radiation situation in perfect simulating natural environment, causes serious restriction for photovoltaic product development.

Summary of the invention

The object of the invention is to overcome above-mentioned deficiency existing in prior art, a kind of a kind of optical element that external stray light can be converted to directional light is provided, thus obtains the unrestricted parallel light generator of a kind of bore.

In order to realize foregoing invention object, the invention provides following technical scheme:

A kind of source of parallel light, comprise light-emitting component and light-transmitting plate, the light that light-emitting component excites is converted into directional light through light-transmitting plate.Described light-transmitting plate internal rule is placed with birefringece crystal.Described birefringece crystal is of a size of the wavelength magnitude of the light that light-emitting component excites, and preferred birefringece crystal is of a size of 300 ~ 900nm, preferred, and crystalline size is 400 ~ 800nm.

The present invention utilizes the light selectivity characteristic of birefringece crystal to realize the object that veiling glare is converted to directional light.Its principle is that employing is of a size of wavelength magnitude in the arrangement of light-transmitting plate internal rule and has the crystal of birefringence.When light wave runs into the particulate of wavelength magnitude, Mie scattering can be there is.And light runs into birefringece crystal is to be separated into ordinary light o light and extraordinary ray e light.And e light, due to its particularity, directly through particulate on a special direction, can not change the direction of propagation of e light in principal section of crystal.Simultaneously suitable for dull and stereotyped and birefringece crystal by selecting, this direction of propagation is exceeded or equals the angle of total reflection of transparent plate, then e light will at light-transmitting plate internal communication to outlet, ensure that simultaneously the direction of propagation by exporting light always can special angle directly through birefringece crystal consistent.And scattering occurs in inside the light of other these special angle non-, until meet the special angle condition exported, thus outgoing.

Compared with prior art, beneficial effect of the present invention: source of parallel light of the present invention solves the problem that source of parallel light in prior art is easily dispersed, more bigbore artificial source of parallel light can be provided, sunshine parallel radiation situation in perfect simulating natural environment, is significant for photovoltaic product development.

Accompanying drawing illustrates:

Fig. 1 is source of parallel light generator architecture schematic diagram.

Fig. 2 is the schematic diagram that light wave runs into the particulate generation Mie scattering of wavelength magnitude.

Fig. 3 is the light path of light in source of parallel light generator inside.

Fig. 4 is the propagation parameter of e light on birefringece crystal surface.

Fig. 5 is the internal structure of source of parallel light generator.

Fig. 6 is a kind of traditional mode principle signal realizing source of parallel light.

Mark in figure: 1-light-transmitting plate, 2-birefringece crystal, 3-light source.

Detailed description of the invention

Birefringence is when ordinary ray enters in anisotropic substance (as calcite, cotton fiber, staple fibre etc.), have except reverberation except on surface, enter each light to foreign substances and can become two light, a light observes the law of refraction, be called ordinary ray, be called for short O light; Another light also reflects not in accordance with the angle of the law of refraction, is called extraordinary ray, is called for short E light.Namely this phenomenon is called birefringence.The specific refractivity of these two light, is just called birefringence.For cotton fiber (positive crystal), the speed of ordinary ray (light of also expressing one's gratification) is greater than extraordinary ray (also known as slower rays).

The anisotropy of crystal is namely along the different directions of lattice, and periodicity and the density degree of atomic arrangement are not quite similar, and causes crystal also different in the physicochemical characteristics of different directions thus, the anisotropy of Here it is crystal.

Light in birefringece crystal meets following propagation rule:

$tan\left(\mathrm{\α}\right)=\frac{n_e^2}{n_o^2}tan\left(\mathrm{\β}\right)$ ①

$n\sin \left(\mathrm{\Φ}\right)=\frac{\sqrt{n_o^2{\cos }^2\left(\mathrm{\β}\right)+n_e^2{\sin }^2\left(\mathrm{\β}\right)}}{\cos \left(\mathrm{\α}-\mathrm{\β}\right)}\cos \left(\mathrm{\θ}+\mathrm{\α}\right)$ ②

Wherein n is the refractive index of transparent plate, n ₀, n _ethe refractive index that in crystal, o light is corresponding with e light respectively.θ is the angle at the optical axis of crystal and interface, and Φ is incidence angle, and α is the angle of e wave normal and optical axis, and β is the angle of e light light and optical axis.

Birefringece crystal arranges at light-transmitting plate inner homogeneous.Light-transmitting plate refractive index is n.Make the optical axis of crystal towards unanimously, and plane of incidence need be parallel to.Namely θ angle is knownly equal 0 °; Due to e light emergent ray and incident light conllinear, and θ=0, then β=90 °-Φ; Equation only has two unknown numbers and α, β thus.Namely 1., 2. solve by formula.β is outgoing optic angle.

During use, by regulating concentrator sensitive surface vertical with β angle, then can obtain the hot spot of concentrator.Thus the detection means realized in laboratory to concentrator and concentrating component.

Further, the structure of described light-transmitting plate is cuboid.Light-transmitting plate is rectangular structure, and its inside arranges birefringece crystal for interception of rays, and light-transmitting plate, mainly as the carrier of crystal, uses as light channel simultaneously.Preferably, the direction of the non-parallel light incidence/outgoing of light-transmitting plate is minute surface (reflecting surface), there is reflection and then again carried out decomposition refraction by birefringece crystal in light, and finally realizes the object of light-transmitting plate injection parallel rays when running into these planes.Namely light-transmitting plate is the light channel structure of beeline channel formula, and its four ring-type walls are reflectings surface.

Further, the refractive index of described birefringece crystal is n _o=1.618, n _e=1.843.N _othe refractive index of o light in crystal, n _ethe refractive index of e light in crystal.

Further, described birefringece crystal is liquid crystal molecule.When liquid crystal molecule is arranged in light-transmitting plate, have the advantages that to be easy to filling and to arrange, queueing discipline degree is good, and the effect focusing on parallel rays is remarkable.

Further, the direction that described light-transmitting plate inside arranges birefringece crystal is that the optical axis of crystal is parallel with plane of light incidence, and the interval anyhow of arrangement is 400 ~ 800nm.When the optical axis of crystal is parallel with plane of light incidence, in the light source injected, the parallel light of major part can directly break-even penetrating and mistake, non-parallel light then reflects between liquid crystal molecule, reflection, transmission be finally converted into the parallel rays of target.

Further, the light direction of light source and light-transmitting plate links together, and fixing structure ensures that connection is between the two more solid and reliable.Preferably, be bonded together by the plane of light incidence of light source and light-transmitting plate, bonding mode is simple, and steadiness is excellent.

Below in conjunction with test example and detailed description of the invention, the present invention is described in further detail.But this should be interpreted as that the scope of the above-mentioned theme of the present invention is only limitted to following embodiment, all technology realized based on content of the present invention all belong to scope of the present invention.

Embodiment 1

As shown in Figure 1, select xenon lamp as the excitation source of source of parallel light 3, the light conduction direction of light source arranges a light-transmitting plate 1, and described light-transmitting plate 1 internal rule is placed with the birefringece crystal calcite (not drawing in Fig. 1) that crystal is of a size of the wavelength magnitude of the light that light-emitting component excites.As shown in Figure 5, birefringece crystal rule be arranged in light-transmitting plate inside.As shown in Figure 2, because the size of birefringece crystal and wavelength of light are at the same order of magnitude, so there is Mie scattering in the calcite of the light that light-emitting component excites in light-transmitting plate.As shown in Figure 4, the light after scattering is separated into ordinary light o light and extraordinary ray e light in birefringece crystal calcite.As shown in Figure 3, e light directly through particulate, does not change and nyctitropicly directly to penetrate from light-transmitting plate light emission side on a special direction; And o light reflects, reflects in transparent plate, and finally transform into the direction injection same with o light, and then make the light of light source activation be converted into directional light.

Embodiment 2

Adopt the birefringece crystal of liquid crystal molecule, be prepared into the crystal fine particle being of a size of 400 ~ 800nm, by the inside being arranged in light-transmitting plate of this birefringece crystal rule, crystal pitch 500nm.Then, this light-transmitting plate is arranged on the light injection port of xenon source, after the original light of light source activation enters light-transmitting plate, is converted into parallel rays, from the opposite side outlet injection of light-transmitting plate.Adopt convex lens to focus on, observe focus size, the angle of divergence of known light source is at about 1 °.

Comparative example 1

Adopt the birefringece crystal being of a size of the crystal fine particle liquid crystal molecule of 1 ~ 5 μm, the inside being arranged in light-transmitting plate of rule, light-transmitting plate is arranged on the light injection port of xenon source, after original light enters light-transmitting plate, from the opposite side outlet injection of light-transmitting plate.

Adopt convex lens to focus on, observe focus size, the depth of parallelism of assessment light.Result shows, and when the diameter of source of parallel light light prepared by this comparative example reaches 100mm, its angle of divergence is at about 2 °.

Comparative example 2

Adopt the method for prior art, directly coordinate convex lens to realize the source of parallel light of 100mm by spot light, it realizes principle as shown in Figure 6.Adopt the depth of parallelism of analysis of test methods its light identical with comparative example 1, result shows, and the angle of divergence of light source, at about 5 °, is difficult to the source of parallel light environment for use meeting high-precision requirement.

The light ray parallel degree of the light-transmitting plate in comparative example 2 and comparative example 2, result display crystal source of parallel light is obviously better than source of parallel light prepared by conventional method.Its depth of parallelism is also obviously better than traditional light source, and the source of parallel light depth of parallelism basic controlling of 100mm of processing preparation, within ± 2 °, can to reach in most preferred situation ± about 1 °.Meanwhile, when adopting crystal source of parallel light, be easy to realize large format source of parallel light.Because only need the size of appearing controlling light source can obtain the source of parallel light of corresponding size.

Comparative example 2 and comparative example 1, when result shows the liquid crystal particle as employing 400 ~ 800nm, because the size of liquid crystal particle is substantially suitable with the wavelength injecting light, the centrifugation of the o light e light of light better can be realized, the effective depth of parallelism ensureing light.And when the size of liquid crystal particle reaches micron level, the size of liquid crystal particle and the wavelength difference of light larger, light is when entering in crystal the separation realizing o light e light, and light refraction transforms insufficient, and the depth of parallelism surface of emergent ray is slightly worse than the less embodiment of size 2.

Claims (4)

1. a source of parallel light, comprises light-emitting component and light-transmitting plate, and the light that light-emitting component excites is converted into directional light through light-transmitting plate;

Described light-transmitting plate internal rule is placed with birefringece crystal;

Described birefringece crystal is of a size of the wavelength magnitude of the light that light-emitting component excites.

2. source of parallel light according to claim 1, is characterized in that, described light-transmitting plate is cuboid.

3. source of parallel light according to claim 1, is characterized in that, described birefringece crystal is liquid crystal molecule.

4. source of parallel light according to claim 1, is characterized in that, the size of described birefringece crystal is 300 ~ 900nm.