JP2014215077A - Light ray property measurement device for light ray directivity control section, and light ray property measurement method for light ray directivity control section - Google Patents

Abstract

PROBLEM TO BE SOLVED: To evaluate an effectiveness of a light ray directivity control section of a light-emitting device without actually fabricating the light-emitting device.SOLUTION: A light ray property measurement device 1 comprises: an evaluation sample 10 including a transparent substrate 13 composed of the same material as a transparent dielectric layer 170 of a light-emitting device 110A, and light ray directivity control sections 11, 12 arranged on the transparent substrate 13 in an annular manner and having the same configuration as light ray directivity control sections 111, 112 of the light-emitting device 110A; a light source 20 irradiating an incidence surface 13a of the transparent substrate 13 with light; and a light detector 30 detecting a light ray emitted from the light ray directivity control sections 11, 12 of the evaluation sample 10 to measure the property. A distance D2 from bottom surfaces of the light ray directivity control sections 11, 12 of the evaluation sample 10 to the incidence surface 13a is equal to a distance D1 from bottom surfaces of the light ray directivity control sections 111, 112 of the light-emitting device 110A to a top face of a light-emitting section 120. The incidence surface 13a of the transparent substrate 13 included in the evaluation sample 10 serves as a diffusion surface.

Description

  The present invention is used in a light emitting element, and includes a light beam characteristic measuring device for a light beam directing control unit and a light beam for a light beam directing control unit for measuring the characteristics of the light beam emitted from a light beam directing control unit that performs light beam formation and direction control. The present invention relates to a characteristic measurement method.

In recent years, an integral photography method (hereinafter referred to as IP) is known as one of three-dimensional image methods that allow a stereoscopic image to be freely viewed without using special stereoscopic glasses from an arbitrary viewpoint.
This IP display system includes a lens array in which a large number of minute lenses (element lenses) that reproduce light rays are arranged, and a display that displays a large number of images (element images) corresponding to each lens. The observer visually obtains partial information corresponding to the position of the observer from one element image corresponding to one element lens, and observes a stereoscopic image in which these are arranged by the number of element lenses. . That is, the resolution of the stereoscopic image is determined by the resolution of the element lens, the resolution of the element image, and the viewing distance, and the performance of the element lens is a dominant factor for the viewing zone angle of the system. Under such circumstances, in order to generate a practical stereoscopic image by the IP method, it is indispensable to increase the definition and function of the light emitting element and the optical element (for example, see Non-Patent Document 1).

  However, even if the definition of the light emitting element and the optical element is increased, there are performance limits that cannot be removed in principle, such as the diffraction limit of the lens and the focal length, in the system using the lens. For example, if the pixel size of the display is smaller than the minimum spot size of the element lens, image blurring occurs, so it is necessary to simultaneously reduce the spot size, but it is impossible in principle to make this smaller than the Abbe diffraction limit. It is. The viewing zone angle in a system using a lens is inversely proportional to the focal length of the element lens, but it cannot be made infinitely small. Furthermore, since the viewing zone angle is also proportional to the pitch of the element lens, there is a trade-off relationship between the resolution and the viewing zone angle in the system using the lens. Therefore, if a light-emitting element that can form a light beam having a minute width according to the surface shape of the element and control the radiation direction without using a lens can be realized, the three-dimensional formation technique can be greatly advanced.

  Based on such an idea, a simple element structure that enables the formation and direction control of light rays with a single light emitting element has been proposed. For example, the applicant of the present application has proposed an element structure as shown in FIG. 5 in Japanese Patent Application No. 2012-38249 and an element structure as shown in FIG. 6 in Japanese Patent Application No. 2012-163779. These element structures will be described with reference to FIGS.

  A light-emitting element 110 illustrated in FIG. 5 includes an n-type semiconductor layer 150, a light-emitting portion 120, and a p-type semiconductor layer 160, and the same material as the p-type semiconductor layer 160 is formed on the p-type semiconductor layer 160. A columnar light beam directing control unit that is formed and serves as a waveguide for the light generated by the light emitting unit 120 is provided. Here, as shown in FIG. 5, the light beam directing control unit is composed of six light beam directing control units, and is arranged on the p-type semiconductor layer 160 in a ring shape. Further, the height of the three light beam direction control units 112 is formed to be different from the height of the other three light beam direction control units 111, and the height of the light beam direction control unit 112 is further set to the light beam direction control. It is formed to be lower than the height of the portion 111.

  In the light emitting element 110 having such a configuration, the light emitting unit 120 emits light generated by recombination of electrons and holes injected from the n-type semiconductor layer 150 and the p-type semiconductor layer 160 as light. The light emitting element 110 can form a light beam by the light emitted from the exit surface of the stigma propagating through the p-type semiconductor layer 160 and the light beam directing control units 111 and 112 to interfere with each other. At this time, the light propagating in the light beam directing control unit 112 having a low height reaches the exit surface of the stigma earlier than the light propagating in the light beam directing control unit 111 having a high height, and thus proceeds faster in the air. . Therefore, the light emitting element 110 can provide a phase difference between the light beam directing control units 111 and 112 having different heights, and can emit a light beam in a direction corresponding to the phase difference. Specifically, as shown in FIG. 5, a light beam inclined with respect to a normal M passing through the center of gravity of the surface of the light emitting element 110 can be formed.

  A light-emitting element 110A illustrated in FIG. 6 is proposed as an element structure that can be more easily manufactured than the light-emitting element 110 illustrated in FIG. In the light emitting element 110A, a transparent dielectric layer 170 formed of a material having a dielectric constant smaller than that of the p-type semiconductor layer 160 is further stacked on the p-type semiconductor layer 160, and a transparent dielectric layer 170 is formed on the transparent dielectric layer 170. It is configured to include columnar light beam directing control units 111 and 112 made of the same material as the body layer 170.

  Here, in the light emitting elements 110 and 110A shown in FIGS. 5 and 6, the light emitting section 120 is uniformly provided on the n-type semiconductor layer 150, but leaks from the element surfaces other than the light beam directing control sections 111 and 112. In order to suppress extraneous interference between the emitted light and the light emitted from the light beam directing control unit and to improve the accuracy of control of the light beam direction, it is preferable to limit the light emitting region to a certain range.

  Therefore, the applicant of the present application provides the light emitting unit 120 in a limited area corresponding to each of the light beam directing control units 111 and 112 as in the light emitting element 110B shown in FIG. A device structure is proposed. Further, in Japanese Patent Application No. 2012-38252, an element structure is proposed in which the light emitting unit 120 is limited to a partial region including directly below the light beam directing control units 111 and 112, as in the light emitting element 110C shown in FIG. ing.

Japan Association for Mechanical Systems Promotion and Japan Optical Industry Technology Promotion Association, “Survey Report on Formation of Spatial Image that Enables Natural Stereoscopic Viewing—Abstract”, System Technology Development Survey 19-R-5, pp .14-16, March 2008

  As shown in FIGS. 5 and 6, the intensity distribution and emission direction (directivity) of the light beam formed by the light beam directing control unit in the conventional light emitting element vary depending on the shape, size, arrangement, etc. of the light beam directing control unit. To do. Therefore, in order to apply such a light emitting element to a pixel or the like of an IP stereoscopic display, precise control of the shape, size, arrangement, etc. of the light beam directing control unit is required. Then, in order to evaluate the validity of the design of the light beam directing control unit and the accuracy of the shape of the light emitting element, it is essential to measure the characteristics of the light beam emitted from the light beam directing control unit.

Here, the conventional light characteristic measuring device of the light beam directing control unit is composed of the light emitting element 110 and the light detecting device 130 like the light characteristic measuring device 101 shown in FIG. 5, for example, as shown in FIG. Like the light characteristic measuring apparatus 101A, the light emitting element 110A and the light detecting apparatus 130 are included. For example, the light characteristic measuring apparatus 101 shown in FIG. 5 has a light beam emitted from the light beam directing control units 111 and 112 of the light emitting element 110 by the light detection device 130 that can move on the orbit as shown by a broken line in FIG. Is detected, and the light intensity distribution and the emission direction (directivity) are measured.
The same applies to the light characteristic measuring apparatus 101A shown in FIG. That is, conventionally, in order to evaluate the validity of the design and the accuracy of the shape of the light beam directing control unit of the light emitting element, the light emitting element has to be actually manufactured and operated. However, it is not easy to evaluate the design validity and the accuracy of the shape of the light beam directing control unit of the light emitting element in this way. The reason is described below.

  For example, in the light emitting device 110 shown in FIG. 5, the light beam directing control units 111 and 112 are formed on the p-type semiconductor layer 160 using a known technique such as a focused ion beam, photolithography, a combination of electron beam lithography and etching. Is formed. Further, for example, by crystal growth or etching of the p-type semiconductor layer 160, the light beam directing control units 111 and 112 made of the same semiconductor material (for example, GaN) are formed on the p-type semiconductor layer 160. However, in this case, strict control of crystal growth conditions is necessary, applicable processing methods are limited depending on the semiconductor material, and physical and chemical damage to the semiconductor is not considered. Therefore, it takes time and labor to manufacture.

  Further, for example, the light emitting element 110A shown in FIG. 6 can be manufactured more easily than the light emitting element 110 shown in FIG. 5, but after the transparent dielectric layer 170 is formed on the p-type semiconductor layer 160, the light beam directing control unit. 111 and 112 are formed by etching, or after the light beam directing control portions 111 and 112 are formed by a transparent dielectric, they must be bonded to the p-type semiconductor layer 160. End up.

  In order to generate light emission in the light emitting portion of these light emitting elements, after the light emitting element is manufactured, an electrode for a p-type semiconductor layer (p-type electrode) and an electrode for an n-type semiconductor layer (n-type electrode) Fine electrodes separated into two are formed, and external wiring from each electrode to an external power supply is required. In the light-emitting element as described above, for example, an electrode for emitting light from the light-emitting portion is provided with a step between the p-type semiconductor layer and the n-type semiconductor layer, as in a general LED element, and is extracted from the step. An ohmic contact is formed on the part. For example, a p-type electrode is provided on the surface of the p-type semiconductor layer, and an n-type electrode is provided on the side surface of the n-type semiconductor layer. Since the p-type electrode and the n-type electrode must be formed of metal materials having different work functions, the number of manufacturing steps increases. Further, since the light emitting element is a fine structure, it takes time and effort to accurately position the electrodes.

  In addition, the characteristics represented by the intensity distribution and the emission direction (directivity) of the light emitted from the light beam directing control unit of the light emitting element are measured by a conventional light characteristic measuring device, and thereby, the design of the light beam directing control unit is measured. If the validity and accuracy of the shape cannot be confirmed, the light emitting element cannot be used as it is for an IP stereoscopic display or the like. Therefore, it takes much more labor and time to find an effective structure as a light beam directing control unit of the light emitting element.

  Further, since the electrodes are formed on the element surface (the p-type semiconductor layer 160 in FIG. 5 and the transparent dielectric layer 170 in FIG. 6) on which the light beam directing control units 111 and 112 are formed, In some cases, the state of light interference changes depending on the shape of the external wiring and the like, which may affect the directivity and shape (thickness) of the light beam. Therefore, even if the characteristics of the light emitted from the light beam directing control unit of the light emitting element are measured, it may be difficult to accurately evaluate the validity of the design of the light beam directing control unit of the light emitting element and the accuracy of the shape. there were.

  As described above, the characteristics of the light beam typified by the intensity distribution and the emission direction of the light beam emitted from the light beam direction control unit of the light emitting element vary due to the shape, size, arrangement, etc. of the light beam direction control unit. . Therefore, if it is known what light rays are emitted from the light beam direction control unit of the light emitting element, the design validity and shape accuracy of the light beam direction control unit of the light emitting element can be obtained without manufacturing the light emitting element itself. Can be evaluated. If the characteristics of the light beam emitted from the light beam directing control unit can be measured without producing a light emitting device, the validity of the design of the light beam directing control unit of the light emitting device and the rapidity and accuracy of the evaluation of the shape accuracy will be dramatically improved. Can be improved. On the other hand, it is not known how the characteristics of the light emitted from the light beam directing control unit of the light emitting element can be measured other than the method of actually manufacturing and operating the light emitting element.

  The present invention has been made in view of the above-described problems. A light beam emitted from the light beam directing control unit of the light-emitting element is simulated and manufactured without actually manufacturing the light-emitting element. It is an object of the present invention to provide a light beam characteristic measuring device of a light beam directing control unit and a light beam characteristic measuring method of a light beam directing control unit capable of measuring characteristics.

  In order to solve the above problem, the light beam characteristic measuring device of the light beam directing control unit according to claim 1, wherein the same light beam directing control unit as the columnar light beam directing control unit formed in the light emitting element to be evaluated is formed of a transparent dielectric. A beam characteristic measuring device of a beam directing control unit that measures the characteristics of a light beam of an evaluation sample formed on a transparent substrate as a light beam characteristic of the light emitting element, wherein the evaluation sample and the evaluation sample And a light detection device for measuring characteristics of light emitted from the light beam directing control unit of the sample for evaluation by light from the light source.

  According to such a configuration, the light beam characteristic measuring apparatus of the light beam directing control unit forms the same light beam directing control unit as the light beam directing control unit of the light emitting element to be evaluated on the transparent substrate formed of the transparent dielectric. Do it. That is, in the sample for evaluation, the light beam directing control unit is made of the same material as the light beam directing control unit of the light emitting element, and has the same size, shape, number, and arrangement.

  Moreover, the light characteristic measuring apparatus of the light beam directing control unit irradiates light directed from the incident surface side of the transparent substrate toward the light beam directing control unit with a light source arranged on the bottom surface side of the sample for evaluation. As described above, since the light characteristic measuring apparatus of the light beam directing control unit uses light generated by the external light source, it is not necessary to form electrodes on the surface of the transparent substrate on which the light beam directing control unit is formed in the sample for evaluation. Therefore, it is not necessary to position the electrodes and install fine wiring for supplying power to the electrodes. Further, it is not necessary to consider the influence on the shape of the light beam due to the formation of the electrode. As the light source, for example, a laser having excellent directivity, an SLD (Super Luminescent Diode), or the like can be used.

  Furthermore, the light beam characteristic measuring device of the light beam directing control unit propagates through the light beam directing control unit of the sample for evaluation by the light detection device, and is formed by interference of light emitted from the exit surface of each stigma. , And the characteristics of this light are measured. Based on the characteristics of the light beam thus measured, it is possible to perform an accurate evaluation such as the validity of the design of the light beam directing control unit of the light emitting element and the accuracy of the shape.

Here, the evaluation sample is such that the distance from the incident surface of the transparent substrate, which is the portion where the light emitted from the light source is incident, to the bottom surface of the light beam directing control unit is from the upper surface of the light emitting unit of the light emitting element to the light beam directing control unit. It is equal to the distance to the bottom. Therefore, the distance until the light incident on the incident surface from the light source is incident on the light beam directing control unit is equal to the distance until the light emitted from the light emitting unit of the light emitting element is incident on the light beam directing control unit. Can do.
In addition, since thickness should just be set suitably about surrounding parts other than the entrance plane in a transparent substrate, if it is sufficient thickness, the intensity | strength of the sample for evaluation can be ensured and handling will become easy.

  By configuring the evaluation sample in this way, the light irradiation pattern irradiated to the light beam directing control unit of the evaluation sample should be the same as the light irradiation pattern irradiated to the light beam directing control unit of the light emitting element. Can do. That is, the light beam directing control unit of the evaluation sample can emit a light beam equivalent to the light beam emitted from the light beam directing control unit of the light emitting element. Therefore, measuring the characteristic of the light beam emitted from the light beam directing control unit of the sample for evaluation can be said to be synonymous with measuring the characteristic of the light beam emitted from the light beam directing control unit of the light emitting element. Therefore, according to the light characteristic measuring apparatus, it is possible to accurately measure the characteristic of light emitted from the light beam directing control unit of the light emitting element without producing the light emitting element. Based on the characteristics of the light beam thus measured, it is possible to perform an accurate evaluation such as the validity of the design of the light beam directing control unit of the light emitting element and the accuracy of the shape.

  According to a second aspect of the present invention, there is provided a light beam characteristic measuring apparatus for a light beam directing control unit according to the first aspect, wherein the evaluation sample has a light incident surface of a transparent substrate as a diffusion surface. Yes. According to this configuration, the light generated by the light source can be diffused on the incident surface to suppress the coherence of the light, and then enter the transparent substrate. When using, for example, a laser having excellent directivity or an SLD (Super Luminescent Diode) as the light source, the light generated by these is much more coherent than the light generated by the light emitting portion of the light emitting element, so that the light is emitted as it is. The same irradiation pattern (far field pattern) as the light generated in the light emitting portion of the element cannot be formed. On the other hand, according to the light beam characteristic measuring apparatus of the light beam directing control unit, the coherence of the light generated by the light source and entering the transparent substrate is suppressed to the same level as the coherence of the light generated by the light emitting unit of the light emitting element. Can do.

  Therefore, by configuring the sample for evaluation in this way, even if the coherence of the light generated by the light source is higher than the coherence of the light generated by the light emitting portion of the light emitting element, it propagates inside the transparent substrate. Thus, the light irradiation pattern applied to the light beam directing control unit can be the same as the light irradiation pattern generated in the light emitting unit of the light emitting element and applied to the light beam directing control unit.

  Furthermore, the light characteristic measuring device of the light beam directing control unit according to claim 3 is the light characteristic measuring device of the light beam directing control unit according to claim 1 or 2, wherein the light detecting device is a light beam of the evaluation sample. The intensity distribution of the light beam emitted from the directivity control unit and the zenith angle of the light beam with respect to the normal passing through the center of gravity of the surface of the evaluation sample are measured as the characteristics of the light beam.

  According to such a configuration, the light characteristic measurement device of the light beam directing control unit detects the light beam emitted from the light beam directing control unit of the evaluation sample by the light detection device, and calculates the shape and the center of gravity of the surface of the evaluation sample. The zenith angle of the ray with respect to the normal passing therethrough is measured as a characteristic of the ray. Based on the characteristics of the light beam thus detected, it is possible to perform an accurate evaluation such as the validity of the design of the light beam directing control unit of the light emitting element and the accuracy of the shape.

  Moreover, in order to solve the said subject, the light beam characteristic measuring method of the light beam direction control part which concerns on Claim 4 of this invention is a light beam of the light beam direction control part as described in any one of Claims 1-3. A beam characteristic measuring method of a beam directing control unit for measuring a characteristic of a light beam emitted from the light beam directing control unit as a characteristic of a light beam emitted from the light beam directing control unit of the light emitting element by a characteristic measuring device. And a light irradiation step and a light characteristic detection step.

  According to such a configuration, the light beam characteristic measuring method of the light beam directing control unit is arranged on the bottom surface of the evaluation sample so that the emission surface of the light source and the incident surface of the transparent substrate of the evaluation sample face each other in the light irradiation step. A light source is disposed, and light is irradiated from the exit surface of the light source to the incident surface. Thereby, a light beam is emitted from the light beam directing control unit of the sample for evaluation. In the light beam characteristic measuring method of the light beam directing control unit, in the light beam characteristic evaluating step, the characteristic of the light beam emitted from the light beam directing control unit of the evaluation sample in the light irradiation step is emitted from the light beam directing control unit of the light emitting element. Measured as the characteristics of the light beam.

  According to such a method of measuring the light beam characteristics of the light beam directing control unit, it is possible to measure the characteristics of the light beam emitted from the light beam directing control unit of the light emitting element without manufacturing the light emitting element itself. Based on the characteristics of the light beam thus measured, it is possible to perform an accurate evaluation such as the validity of the design of the light beam directing control unit of the light emitting element and the accuracy of the shape.

The present invention has the following excellent effects.
According to the first and fourth aspects of the invention, the characteristics of the light beam emitted from the light beam directing control unit of the sample for evaluation can be measured as the characteristics of the light beam emitted from the light beam directing control unit of the light emitting element. Even without manufacturing the light emitting element itself, it is possible to measure the characteristics of light emitted from the light beam directing control unit of the light emitting element. As a result, it is possible to quickly and accurately evaluate the validity of the design of the light beam directing control unit of the light emitting element and the accuracy of the shape. Therefore, it is possible to quickly and easily find a structure effective as the light beam directing control unit of the light emitting element.

  According to the second aspect of the present invention, even when the coherence of the light generated by the light source is higher than the coherence of the light generated by the light emitting unit of the light emitting element, the light beam directing control unit is irradiated by the light source. The light irradiation pattern can be the same as the light irradiation pattern irradiated to the light beam directing control unit by the light emitting unit of the light emitting element.

  According to the invention which concerns on Claim 3, the characteristic of the light ray radiate | emitted from the light beam direction control part of a light emitting element can be measured for the characteristic of the light ray radiate | emitted from the light beam direction control part of the sample for evaluation. As a result, it becomes possible to quickly and accurately evaluate the validity of the design of the light beam directing control unit of the light emitting element and the accuracy of the shape.

It is a block diagram which shows typically the light characteristic measuring apparatus of the light directivity control part which concerns on embodiment of this invention. (A) is a figure which shows the irradiation pattern of the light from the light emission part of the conventional light emitting element to the light beam direction control part, (b) is for evaluation from the light source of the light characteristic measuring apparatus which concerns on embodiment of this invention. It is a figure which shows the irradiation pattern of the light to the light beam orientation control part of a sample. It is a flowchart which shows the method of measuring the characteristic of the light beam of a light beam direction control part by the light beam characteristic measurement apparatus of the light beam direction control part of embodiment of this invention. (A) is a figure which shows the irradiation pattern of the light from the light emission part of the conventional light emitting element to the light beam orientation control part, (b) is the light source of the light characteristic measuring apparatus which concerns on the modification of embodiment of this invention. It is a figure which shows the irradiation pattern of the light to the light beam directing control part of the sample for evaluation. It is a block diagram which shows typically an example of the conventional light characteristic measuring apparatus. It is a block diagram which shows typically an example of the conventional light characteristic measuring apparatus. It is a block diagram which shows typically an example of the conventional light emitting element. It is a block diagram which shows typically an example of the conventional light emitting element.

  Hereinafter, a light characteristic measuring device of a light beam directing control unit according to an embodiment of the present invention will be described with reference to the drawings. In addition, the dimension of the member which each drawing shows, the positional relationship, etc. may be exaggerated for convenience of explanation. Furthermore, in the following description, the same name and reference sign indicate the same or the same members in principle, and the detailed description will be omitted as appropriate.

The configuration of the light characteristic measuring device of the light directivity control unit according to the embodiment of the present invention will be described.
As shown in FIG. 1, the light characteristic measurement device 1 includes an evaluation sample 10, a light source 20, and a light detection device 30. In FIG. 1, the light source 20 is shown in a simplified manner. In the following, the configuration of the evaluation sample 10 shown in FIG. 2B will be referred to as appropriate with reference to FIGS. 2A and 2B and appropriately compared with the conventional light emitting device 110A shown in FIG. Will be explained. Note that the structure of the light-emitting element 110A illustrated in FIG. 2A is similar to the structure of the light-emitting element 110A described with reference to FIG. In the light emitting device 110A shown in FIG. 2A, a p-type electrode 180 is formed on the upper surface of the transparent dielectric layer 170, and an n-type electrode 190 is formed on the lower surface of the n-type semiconductor layer 150.

  As shown in FIG. 1 and FIG. 2 (b), an evaluation sample 10 includes a columnar light beam directing control unit 11, 12, a transparent substrate 13 formed below the light beam directing control unit 11, 12, It is configured with.

  The light beam directing control units 11 and 12 have the same configuration as the light beam directing control units 111 and 112 of the light emitting element 110A shown in FIG. That is, the light directivity control units 11 and 12 of the evaluation sample 10 shown in FIG. 2B are formed of the same transparent dielectric as the light directivity control units 111 and 112 of the light emitting element 110A shown in FIG. And are composed of the same dimensions, shapes and numbers. Further, the arrangement of the light beam directing control units 11 and 12 on the surface of the evaluation sample 10 shown in FIG. 2B corresponds to the arrangement of the light beam directing control units 111 and 112 on the surface of the light emitting element 110A shown in FIG. It is the same as the arrangement.

In the light emitting device 110A shown in FIG. 2A, when the n-type semiconductor layer 150 and the p-type semiconductor layer 160 are made of, for example, GaN, the light beam directing control units 111 and 112 and the transparent dielectric layer 170 are It is formed of a transparent dielectric material such as SiO ₂ , SiO, SiN, MgF ₂ , ZrO ₂ or the like having a dielectric constant and refractive index lower than those of GaN. Therefore, the light beam directing control units 11 and 12 of the evaluation sample 10 shown in FIG. 2B are also formed of any one of these transparent dielectrics. The detailed configuration of the light emitting element 110A shown in FIG. 2A is as described in the already filed Japanese Patent Application No. 2012-163779, and thus detailed description thereof is omitted here.

  As shown in FIG. 1, the light beam directing control units 11 and 12 are formed at different heights for every three. That is, as shown in FIG. 1, the light beam direction control units 11 and 12 are arranged such that the heights of the three light beam direction control units 12 arranged adjacent to each other are the other three light beam directions arranged adjacent to each other. It is formed to be different from the height of the control unit 11, and here, the height of the light beam directing control unit 12 is formed to be lower than the height of the light beam directing control unit 11.

  Thus, by setting the three light beam directing control units 12 and the other three other light beam directing control units 11 to different heights, the light emission direction (zenith angle) is changed according to the height difference. Can be controlled. As shown in FIG. 1, the zenith angle means an angle in the light emission direction with respect to the normal M passing through the center of gravity of the surface of the evaluation sample 10. When the heights of the light beam directing control units 11 and 12 are all the same (when there is no difference in height), the light beam formed by the light beam directing control units 11 and 12 is perpendicular to the surface of the evaluation sample 10. Radiated in the direction.

  The light beam directing control units 11 and 12 function as a waveguide for light generated by the light source 20. Here, for example, when an SLD is used as the light source 20, since the coherence length of the SLD is generally about 10 μm, light having a different path length in a minute space forms a spatial distribution due to the interference effect. Therefore, the light propagating through the light beam directing control units 11 and 12 passes from the exit surfaces 11a and 12a (see FIG. 2B) which are the uppermost surfaces of the light beam directing control units 11 and 12 to the surface of the evaluation sample 10. After being radiated in the vertical direction, that is, in the upward direction in FIG. 1, one light beam is emitted from the center of gravity of the surface of the evaluation sample 10 in the direction perpendicular to the surface of the evaluation sample 10 due to the light interference effect. Generated. In addition, the surface of the sample 10 for evaluation here specifically means the upper surface of the transparent substrate 13 shown in FIG. In addition, the light beam here means light that spreads.

  The beam directing control units 11 and 12 are each formed in a circular shape in plan view, and are formed on the transparent substrate 13 with the same cross-sectional area. The light beam directing control units 11 and 12 are formed so that the diameters thereof are equal to each other, and specifically, are set to about the wavelength of light in free space (in the air). The light beam directing control units 11 and 12 are arranged in an annular shape so that the central axes of the respective columns are positioned at equal intervals on the same circumference.

The height of the light beam directing control unit 11 and the height of the light beam directing control unit 12 are set to about the wavelength of light propagating through the light beam directing control units 11 and 12, or several times as high as that. Here, the height of the light beam directing control unit 11 is “H”, the height difference between the light beam directing control unit 11 and the light beam directing control unit 12 is “d”, and the height difference d with respect to the height H is The ratio (= d / H) is “δ”. In this case, the height difference d between the light beam directing control unit 11 and the light beam directing control unit 12 can be expressed by d = δH. In the following description, the ratio δ of the column height difference d with respect to the height H of the beam directing control unit 11 will be described as “column height difference ratio δ”. Increasing the column height difference ratio δ increases the angle θ ₁ (hereinafter referred to as the zenith angle θ ₁ , see FIG. 2B) formed by the light beam in the direction perpendicular to the surface of the sample 10 for evaluation. Details of the direction control of the light beam by the light beam direction control units 11 and 12 are the same as the direction control of the light beam by the light beam direction control units 111 and 112 of the light emitting element 110A shown in FIG. The detailed explanation is omitted.

  The transparent substrate 13 supports the light beam directing control units 11 and 12. The transparent substrate 13 is formed of a transparent dielectric, has a flat surface, and has a rectangular surface shape. The surface area of the transparent substrate 13 is formed to be equal to the surface area of the transparent dielectric layer 170 of the light emitting device 110A shown in FIG. Here, the transparent substrate 13 is formed of the same transparent dielectric as the light beam direction control units 11 and 12. The transparent substrate 13 is not limited to this, and may be formed using glass or a resin material such as a thermoplastic resin or a photo-curing resin.

As shown in FIG. 2B, the transparent substrate 13 includes an incident surface 13a on which light generated by the light source 20 is incident.
Here, as with the light emitting element 110B shown in FIG. 7, one incident surface 13 a is provided in a partial region including the portion directly below the light beam directing control units 11 and 12 on the bottom surface of the transparent substrate 13. The incident range of the incident surface 13a (the area of the cross section of the incident surface 13a) is designed so that the light from the light source 20 can be sufficiently incident on all the light beam directing control units 11 and 12.

  For example, the area of the cross section of the incident surface 13a may be formed so as to be equal to or less than the area of a circumscribed circle including all of the light beam directing control units 11 and 12. If it does in this way, it can suppress that the light which injected from the entrance plane 13a leaks out from the surface of the sample 10 for evaluation other than the light beam direction control parts 11 and 12. FIG. Therefore, it is possible to suppress an extra interference effect caused by the light leaking from the surface of the evaluation sample 10 and the light emitted from the emission surfaces 11a and 12a of the light beam directing control units 11 and 12, respectively. .

  Further, for example, the area of the cross section of the incident surface 13a may be formed to be equal to or greater than the sum of the areas of the cross sections of the columns of the light beam directing control units 11 and 12. In this way, most of the light incident from the incident surface 13 a can be incident on the light beam directing control units 11 and 12. Therefore, it is possible to increase the intensity of light emitted from the emission surfaces 11a and 12a of the beam directing control units 11 and 12.

  As shown in FIG. 2B, the transparent substrate 13 has a distance D2 from the bottom surface (incident interface) of the light beam directing control units 11 and 12 to the incident surface 13a of the light emitting element 110A shown in FIG. It is equal to the distance D1 from the bottom surface (incident interface) of the light beam directing control units 111 and 112 to the top surface of the light emitting unit 120.

  By configuring the transparent substrate 13 in this way, the light generated by the light source 20 shown in FIG. 2B propagates through the transparent substrate 13 of the evaluation sample 10 to the light beam directing control units 11 and 12. The distance until the light enters and the light generated in the light emitting unit 120 of the light emitting element 110A shown in FIG. 2A propagates through the p-type semiconductor layer 160 and the transparent dielectric layer 170, and the light beam directing control unit. It is possible to make the distances until they are incident on 111 and 112 equal.

  As shown in FIG. 2 (b), the incident surface 13a of the transparent substrate 13 is a known ion beam (FIB: Focused Ion Beam), a combination of photolithography, electron beam lithography and etching, anisotropic etching, or the like. It can be formed by technology. For example, by etching a predetermined amount from the bottom surface side to the front surface side so as to form a concave hole having the same diameter as that of the incident surface 13a at a predetermined position of the transparent substrate 13, the thickness of the transparent substrate 13 is increased. The incident surface 13a can be formed at a predetermined position.

  In the transparent substrate 13, the thickness of the portion other than the incident surface 13a is not particularly limited. For example, the thickness of the transparent substrate 13 from the front surface to the bottom surface is equal to the thickness from the surface of the transparent dielectric layer 170 of the light emitting element 110A shown in FIG. 2A to the bottom surface of the n-type semiconductor layer 150. It may be formed. Thus, by forming the transparent substrate 13 with a sufficient thickness, the strength of the evaluation sample 10 can be ensured, and the handling becomes easy.

  As shown in FIG. 2B, the incident surface 13a of the transparent substrate 13 is a diffusing surface. For example, the surface can be roughened by making fine scratches on the incident surface 13a, so that the diffusion surface can be obtained. The degree of diffusion can be appropriately set according to the degree of coherence of light generated by the light source 20.

  When a laser or SLD with excellent directivity is used as the light source 20, for example, the light generated by these is much more coherent than the light generated by the light emitting unit 120 of the light emitting element 110A shown in FIG. high. Since the degree of coherence is different in this way, even if the light generated by the light source 20 is irradiated on the incident surface 13a without any modification, the same irradiation pattern as the light generated by the light emitting unit 120 of the light emitting element 110A is formed. It is not possible. On the other hand, in the sample 10 for evaluation shown in FIG. 2B, since the incident surface 13a of the transparent substrate 13 is a diffusing surface, highly coherent light generated by the light source 20 is diffused by the incident surface 13a. Then, the coherence of the light generated by the light source 20 is suppressed to the same level as the coherence of the light generated by the light emitting unit 120 of the light emitting element 110A shown in FIG. 13 can be incident.

As described above, the evaluation sample 10 shown in FIG. 2B has the light beam directing control units 111 and 112 of the light emitting element 110A shown in FIG. 2A on the surface (the surface of the transparent substrate 13). The beam directing control units 11 and 12 having the same configuration are provided.
Further, in the evaluation sample 10 shown in FIG. 2B, the distance D2 from the surface (the surface of the transparent substrate 13) to the incident surface 13a is such that the surface of the light emitting element 110A shown in FIG. It is equal to the distance D1 from the surface of the body layer 170 to the upper surface of the light emitting unit 120.
Further, in the evaluation sample 10 shown in FIG. 2B, the incident surface 13a of the transparent substrate 13 is a diffusion surface.

  By configuring the evaluation sample 10 in this way, the irradiation pattern of the light irradiated from the light source 20 to the light beam directing control units 11 and 12 is changed from the light emitting unit 120 of the light emitting element 110A shown in FIG. It can be the same as the irradiation pattern of the light irradiated to the directivity control units 111 and 112.

  Therefore, the light rays that propagate through the light beam directing control units 11 and 12 of the evaluation sample 10 shown in FIG. 2B and are formed by the interference of the light emitted from the emission surfaces 11a and 12a are shown in FIG. The light beam propagates through the light beam directing control units 111 and 112 of the light emitting element 110A shown in a), and is equivalent to a light beam formed by interference of light emitted from the emission surfaces 111a and 112a. Therefore, measuring the characteristics of the light beam formed by the light beam directing control units 11 and 12 of the evaluation sample 10 shown in FIG. 2B is the light beam directing control of the light emitting element 110A shown in FIG. It can be said that it is synonymous with measuring the characteristics of the light beam formed by the portions 111 and 112.

  The sample 10 for evaluation can be formed by processing a rectangular transparent dielectric material having a total thickness of the heights of the light beam directing control units 11 and 12 and the thickness of the transparent substrate 13. Specifically, the beam directing control units 11 and 12 use, for example, a known technique such as a focused ion beam (FIB), photolithography, a combination of electron beam lithography and etching, or the like to form a transparent dielectric material. It can be easily formed by processing. Further, the incident surface 13a of the transparent substrate 13 can be easily formed by using a known technique such as anisotropic etching.

  Here, as shown in FIG. 1, such an evaluation sample 10 is mounted on a mounting table 40 that supports the transparent substrate 13 from the bottom surface side. Since the light source 20 is disposed immediately below the incident surface 13a of the transparent substrate 13, the mounting table 40 is provided except for this portion.

  As shown in FIGS. 1 and 2B, the light source 20 generates light by power supplied from an external power source (not shown), and the generated light is incident on the incident surface 13a of the transparent substrate 13 of the evaluation sample 10. Irradiation. The light source 20 is disposed immediately below the incident surface 13a of the evaluation sample 10, and is disposed such that the light exit surface 20a faces the incident surface 13a. In the light source 20, the area of the cross section of the light irradiated by the exit surface 20a is substantially equal to the area of the cross section of the incident surface 13a of the evaluation sample 10. Accordingly, the light generated by the light source 20 can be incident on the entire incident surface 13a of the evaluation sample 10.

  As the light source 20, for example, a laser or an SLD can be used. Since the light formed by the laser or SLD has high directivity, the light source 20 and the sample 10 for evaluation are arranged apart from each other, and the distance from the light emission surface of the light source 20 to the incident surface 13a of the transparent substrate 13 is long. Even in this case, a sufficient amount of light can be incident on the incident surface 13a while suppressing the spread of the light beam.

  The light detection device 30 is disposed above the evaluation sample 10 at a predetermined distance, detects the light beam formed by the light beam directing control units 11 and 12, and measures its characteristics. The light detection device 30 is connected to a drive device via an arm (not shown). Although not shown here, the light detection device 30 includes a camera unit that captures the light beam formed by the light beam directing control units 11 and 12 of the evaluation sample 10 and a control unit that integrates the intensity distribution of the captured light beam. I have. Note that the control unit need not be included in the light detection device 30, and a control device (not shown) connected to the light detection device 30 may perform processing by the control unit.

Here, a hemisphere arranged so as to cover the evaluation sample 10 is assumed. The sample 10 for evaluation shall be arrange | positioned at the inner bottom face of a hemisphere so that a gravity center may be located coaxially with the zenith part of a hemisphere. At this time, the light detection device 30 can detect light rays from various directions by moving along a predetermined trajectory so as to trace the surface of the hemisphere. The predetermined trajectory is a trajectory that goes from a point A on the circumference of the bottom surface of the hemisphere to a point B that passes through the reference position (the zenith portion) and faces the point A on the circumference.
In the light detection device 30, the reference position is a position where the zenith portion of the hemisphere and the center of the lens surface (not shown) are coaxial. The light detection device 30 determines the zenith angle θ ₁ of the light beam from its own position (distance and direction from the reference position) when the light beam emitted from the light beam directing control units 11 and 12 of the evaluation sample 10 is incident. It is designed to measure as a characteristic. The light detection device 30 captures a light beam incident perpendicularly to a lens surface (not shown) of the camera unit, and measures the intensity distribution of the light beam as a characteristic of the light beam.

Further, the light detection device 30 has a zenith angle of the light beam with respect to the normal M passing through the center of gravity of the surface of the evaluation sample 10 on which the light beam directing control units 11 and 12 of the evaluation sample 10 shown in FIG. Measure θ ₁ . The light detection device 30 measures the zenith angle θ _{1 of the} light beam for each of the plurality of evaluation samples 10 having different column height difference ratios δ.

In this way, by evaluating the characteristics of the light beam measured by the light detection device 30, it is possible to confirm whether the design validity and the shape accuracy of the light beam directing control units 11 and 12 are ensured. .
Note that the evaluation of the characteristics of the light beam described above may be performed by a control unit (not shown) of the light detection device 30.

A method of measuring the characteristics of the light beam emitted from the light beam directing control unit of the light emitting element by using the light beam characteristic measuring apparatus 1 will be described with reference to FIG. 3 and FIGS.
First, light generated by the light source 20 by placing the evaluation sample 10 on the upper side of the light source 20 so that the emission surface 20a of the light source 20 and the incident surface 13a of the transparent substrate 13 of the evaluation sample 10 face each other. Irradiate the incident surface 13a of the transparent substrate 13 (step S1: light irradiation step).
Thereby, the light generated by the light source 20 is incident on the inside of the transparent substrate 13 and propagated, and is incident on the inside from the bottom surfaces of the light beam directing control units 11 and 12. Then, light is propagated by the light beam directing control units 11 and 12 of the evaluation sample 10 and is emitted from the exit surfaces 11a and 12a of the stigma into the air. A light beam is formed by mutual interference of light emitted from the exit surfaces 11a and 12a. In this way, light rays are emitted from the light beam directing control units 11 and 12 of the evaluation sample 10.

Then, the light detector 30 detects the light beams emitted from the light beam directing control units 11 and 12 of the evaluation sample 10 in step S1, and determines the light intensity distribution (light beam shape) and the light beam zenith angle θ _1. Measurement is performed (step S2: light characteristic measurement step). The light detection device 30 measures the intensity distribution of the light beam and the zenith angle θ _{1 of the} light beam for each of the plurality of evaluation samples 10 having different column height difference ratios δ.

  According to the light beam characteristic measuring apparatus and the light beam characteristic measuring method of the light beam directing control unit according to the embodiment of the present invention described above, the characteristics of the light beam formed by the light beam directing control unit of the sample for evaluation are changed to the light beam directivity of the light emitting element. Since it can be measured as the characteristic of the light beam formed by the control unit, the characteristic of the light beam formed by the light beam directing control unit of the light emitting element can be measured without manufacturing the light emitting element itself. As a result, it is possible to quickly and accurately evaluate the validity of the design of the light beam directing control unit of the light emitting element and the accuracy of the shape.

Further, according to the light beam characteristic measuring device and the light beam characteristic measuring method of the light beam directing control unit, since the evaluation sample can form a light beam by the light generated by the light source, the light beam directing control unit is formed in the evaluation sample. It is not necessary to form electrodes on the surface of the transparent substrate. Therefore, it is not necessary to position the electrodes and install fine wiring for supplying power to the electrodes. Further, it is not necessary to consider the influence on the shape of the light beam due to the formation of the electrode. Thereby, it becomes possible to perform quicker and more accurate evaluation of the validity of the design of the light beam directing control unit of the light emitting element and the accuracy of the shape.
Thus, according to the light beam characteristic measuring apparatus and the light beam characteristic measuring method of the light beam directing control unit, it is possible to quickly and easily find an effective structure as the light beam directing control unit of the light emitting element.

  Then, according to the light beam characteristic measuring device and the light beam characteristic measuring method of the light beam directing control unit, when the effectiveness of the light beam directing control unit of the evaluation sample is confirmed, the light beam directing control unit is moved to the light beam directing control of the evaluation sample. By manufacturing the light emitting element having the same configuration as the unit, it is possible to reduce the waste of materials as compared with the case where the light emitting element itself is manufactured and the effectiveness of the light beam directing control unit is confirmed.

As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to above-described embodiment.
For example, the light characteristic measuring apparatus 1 may use an evaluation sample 10A shown in FIG. 4B instead of the evaluation sample 10 shown in FIG. The evaluation sample 10A shown in FIG. 4B is different from the evaluation sample 10 shown in FIG. 2B on the transparent substrate 13 on the incident surface 13a corresponding to each of the beam directing control units 11 and 12. Is different. That is, the evaluation sample 10 </ b> A shown in FIG. 4B has six incident surfaces 13 a formed on the bottom surface of the transparent substrate 13 corresponding to the number of the light beam directing control units 11 and 12.

  In the evaluation sample 10A shown in FIG. 4B, the cross-sectional area of each incident surface 13a of the transparent substrate 13 is sufficient to allow the light from the light source 20 to be incident on the corresponding beam directing control units 11 and 12. It is designed to be large enough. The method of setting the cross-sectional area of the incident surface 13a with respect to the cross-sectional area of the beam directing control units 11 and 12 is performed in the same manner as the light emitting element 110C shown in FIG. 8 (see Japanese Patent Application No. 2012-38250 already filed). be able to. The light emitting element 110A illustrated in FIG. 4A is the same as the light emitting element 110A illustrated in FIG. 2A, but the light emitting unit 120 is provided for each column in the same idea as the light emitting element 110C illustrated in FIG. Is divided.

1,1A light characteristic measuring device (light characteristic measuring device of light directivity control unit)
10, 10A Evaluation Sample 11 Light Direction Control Unit 11a Emission Surface 12 Light Direction Control Unit 12a Emission Surface 13 Transparent Substrate 13a Incidence Surface 20 Light Source 30 Photodetector 40 Mounting Base 110, 110A, 110B, 110C Light Emitting Element 111 Light Direction Control Unit 112 beam directing control unit 120 light emitting unit 130 photodetector 150 n-type semiconductor layer 160 p-type semiconductor layer 170 transparent dielectric layer 180 p-type electrode 190 n-type electrode

Claims (4)

The light beam characteristics of the sample for evaluation formed on the transparent substrate in which the same light beam directing control unit as the columnar light beam directing control unit formed in the light emitting element to be evaluated is formed of a transparent dielectric material, the light beam characteristics of the light emitting element A beam characteristic measuring device of a beam directing control unit to measure as
The evaluation sample;
A light source installed on the bottom side of the sample for evaluation;
A light detecting device that detects light emitted from the light beam directing control unit of the sample for evaluation by light from the light source and measures the characteristics of the light; and
In the transparent substrate of the sample for evaluation, the distance from the incident surface on which light emitted from the light source is incident to the bottom surface of the light beam directing control unit is from the upper surface of the light emitting unit of the light emitting element to the light beam directing control unit. The light beam characteristic measuring device of the light beam directing control unit characterized by being equal to the distance to the bottom surface of the light beam.   2. The light characteristic measuring apparatus for a light beam directing control unit according to claim 1, wherein in the evaluation sample, the incident surface of the transparent substrate is a diffusion surface. 3.   The light detection device includes: an intensity distribution of the light beam as a characteristic of the light beam emitted from the light beam directing control unit of the evaluation sample; and a zenith angle of the light beam with respect to a normal passing through the center of gravity of the surface of the evaluation sample. The light characteristic measuring device for a light beam directing control unit according to claim 1, wherein the light characteristic measuring device measures the light characteristic. The light beam emitted from the light beam directing control unit by the light beam characteristic measuring device of the light beam directing control unit according to any one of claims 1 to 3, and the light beam emitted from the light beam directing control unit of the light emitting element. A beam characteristic measuring method of a beam directing control unit for detecting as
The light source is arranged on the bottom surface of the evaluation sample so that the emission surface of the light source and the incidence surface of the transparent substrate of the evaluation sample face each other, and light is emitted from the emission surface of the light source to the incidence surface. A light irradiation step for irradiating;
A light characteristic measuring step of measuring a characteristic of a light beam emitted from the light beam directing control unit by the photodetecting device;

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