JP2006214818A - Flaw detecting method of optical component and flaw detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flaw detecting method of an optical component capable of detecting the flaw of the optical component, which is constituted by laminating a plurality of layers having light perviousness, without being restricted by the size of the optical component, and a flaw detector. <P>SOLUTION: Detecting light 38 is emitted from a light source 36 that is made to enter one surface part 35a of the optical component 35 from the light source 36, on the basis of the refractive indexes of the respective layers of the optical component 35 by a prism 32, to decide the waveguide route of the detecting light 38. By using this method, the detecting light 38 can be made to enter so as to induce a multiple bonds by at least one of the respective layers of the optical component 35, and a part of the detecting light 38 is guided to the layer of which the flaw should be detected to detect the flaw 45. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical component defect detection method and a defect detection device for detecting a defect of an optical component configured by laminating a plurality of layers having translucency.

  FIG. 7 is a perspective view showing a transparent substrate defect detection apparatus 1 according to the first prior art. Laser light 2 a emitted from the laser 2 is guided to the end surface of the transparent substrate 5 through the plurality of mirrors 3 and the condenser lens 4, and is repeatedly reflected at both end surfaces in the thickness direction of the transparent substrate 5. When the transparent substrate 5 has a defect, the light is scattered due to the defect, and the scattered light is emitted to the outside of the transparent substrate 5. The scattered light is guided to the CCD 7 by the imaging lens 6, and the presence or absence of a defect is determined based on the amount of light received by the CCD 7 (see, for example, Patent Document 1).

  FIG. 8 is a block diagram schematically showing a control system of the defect detection apparatus 10 of the second prior art. In this detection apparatus 10, since the thin film portion 12 of the inspection object 11 is very thin, it is inspected using a pseudo surface wave. The emitted laser beam 13 is introduced into the inside of the crystal substrate 11 by the prism 14, guided to the opposite side of the introduction surface, and becomes a pseudo surface wave that advances the surface of the multilayer film 12. When the pseudo surface wave passes near the defect, diffracted light or scattered light is generated, and the diffracted light or scattered light is detected by the light receiving element 15. Therefore, the presence / absence of a defect is determined by the amount of light detected by the light receiving element 15 (see, for example, Patent Document 2).

  FIG. 9 is a front view showing the relationship between the prism coupler 21 and the substrate used in the third conventional defect detection apparatus. In the prism coupler 21, an optical waveguide layer 22, a gap adjusting layer 23, and a high refractive index layer 24 are sequentially stacked on a substrate, and the refractive index of the surface portion of the high refractive index is higher than that of the high refractive index layer 24. A high high refractive index prism 25 is formed. Therefore, when the light 26 is incident on the prism coupler 21, the waveguide mode light of the optical waveguide layer 22 is incident on the incident light via the evanescent wave generated at the interface between the high refractive index layer 24 and the gap adjusting layer 23. And it couple | bonds with emitted light (for example, refer patent document 3).

Japanese Patent Laid-Open No. 11-190700 JP-A 64-23144 JP-A-2-213808

  In the first prior art, when the optical component is a laminated optical component, if there is non-uniformity in the layers constituting the laminated optical component for which a defect is to be detected, multiple coupling of light occurs, Since the attenuation rate of the antenna increases, it cannot propagate over a long distance. Therefore, in the first conventional technique in which light is incident from the end face of the optical component, there is a problem that as the surface area, that is, the size of the optical component increases, the vicinity of the center of the optical component separated from the end face cannot be inspected. is there.

  As in the second prior art, a method for detecting defects by introducing light into an object to be detected from other than the end face of the optical component to generate a pseudo surface wave has a certain thickness. In the inspection of a laminated optical component in which layers are laminated, there is a problem in that the surface to be inspected is only the uppermost surface portion in the pseudo surface wave, and the inside of the laminated optical component including other layers cannot be inspected. is there.

  The third conventional technique is one of the techniques that can introduce light into a laminated optical component as well as the second conventional technique in the prism coupling technique used for the optical waveguide device. This is a technique for guiding light by using an evanescent wave oozing effect that occurs only when the layer is in between, for example, a layer having a thickness of air of sub-micron or less. Therefore, as in the second conventional technique, the present invention can be applied only to a thin film device such as an optical waveguide device in which the light guide portion is only near the surface of the device, and it detects a defect inside the laminated optical component. I can't.

  Further, in the second and third conventional techniques, even when the defect is detected through the film in a state where the surface of the optical component is protected by the film, the optical coupling by the evanescent wave and the pseudo surface wave are also used. I can't. Therefore, there is a problem that the defect of the optical component whose surface is protected by the film cannot be detected.

  Accordingly, an object of the present invention is to provide an optical component defect detection method capable of detecting a defect of an optical component formed by laminating a plurality of layers having translucency without being restricted by the size of the optical component, and It is to provide a defect detection apparatus.

The present invention provides a method for detecting a defect in an optical component in which a plurality of layers are stacked.
An optical component defect comprising a waveguide path determining step for determining a waveguide path of detection light by making detection light incident from one surface portion of the optical component based on the refractive index of each layer It is a detection method.

  According to the present invention, based on the refractive index of each layer, detection light is incident from one surface portion of the optical component, and the waveguide path of the detection light is determined. As a result, the detection light can be incident on at least one of the layers constituting the optical component so as to induce multiple coupling. Therefore, even if the incident angle of the optical component for the detection light is incident at an angle that is not totally reflected at the intermediate boundary, a part of the detection light is guided by another guide that takes a waveguide path due to total reflection due to multiple coupling. The phenomenon of changing to light can be caused. In other words, a part of the detection light can be changed to a light guide path different from the incident light path by the action of multiple coupling. As a result, part of the detection light can be guided to the layer where the defect is to be detected.

  In the invention, it is preferable that the waveguide path determination step includes a step of causing detection light to be incident on the one surface portion from a light source through an optical coupling unit.

  According to the present invention, the waveguide path determination step includes a step of causing detection light to enter the one surface portion from the light source via the optical coupling means. Therefore, the amount of attenuation can be reduced by making the amount of light for detection incident through the optical coupling means rather than entering the optical component through air.

  According to the present invention, the waveguide path determination step includes a step of inducing multiple coupling by an optical component.

  According to the present invention, the waveguide path determination step includes the step of inducing multiple coupling by the optical component, so that the detection light incident from one surface portion of the optical component is introduced into the optical component as described above. Can be guided reliably.

  In the invention, it is preferable that the waveguide path determination step includes a step of inducing a leaky wave with an optical component.

  According to the present invention, the waveguide path determination step includes a step of inducing a leaky wave in the optical component. Thus, even when a gap is formed between the optical coupling means and the optical component, the detection light can be easily incident on the inside of the optical component at an angle that is not totally reflected by the bottom surface of the optical coupling means. In addition, the detection light that enters the optical component also changes from the leaky wave that propagates without total reflection to the light that guides the layer to be detected while performing total reflection. Even when a gap is generated between the coupling means and the optical component, the detection light inside the optical component can be guided and a defect can be detected.

  Furthermore, the present invention further includes a relative displacement step of relatively displacing the light source with respect to one surface portion of the optical component.

  According to the invention, there is further provided a relative displacement step of relatively displacing the light source with respect to one surface portion of the optical component. As a result, even if the optical component has a strong multi-coupling property and a short light guide distance, the incident position of the light for detection into the optical component is not limited. Defects in the shape of optical components can also be detected.

Furthermore, the present invention provides an apparatus for detecting a defect in an optical component in which a plurality of layers are stacked.
A light source;
An optical system comprising: a waveguide path determining unit that determines the waveguide path of the detection light by causing detection light to enter the surface of the optical component from the light source based on the refractive index of each layer. This is a component defect detection apparatus.

  According to the present invention, the detection light is emitted from the light source, and the detection light is incident on the one surface portion of the optical component from the light source based on the refractive index of each layer of the optical component by the waveguide determining unit. Determine the waveguide path of the detection light. As a result, the detection light can be incident on at least one of the layers constituting the optical component so as to induce multiple coupling. Therefore, even if the incident angle of the optical component for the detection light is incident at an angle that is not totally reflected at the intermediate boundary, a part of the detection light is guided by another guide that takes a waveguide path due to total reflection due to multiple coupling. The phenomenon of changing to light can be caused. In other words, a part of the detection light can be changed to a light guide path different from the incident light path by the action of multiple coupling. As a result, part of the detection light can be guided to the layer where the defect is to be detected.

Further, according to the present invention, the waveguide path determination means includes an optical coupling means,
The detection light from the light source is incident on the optical component through the optical coupling means.

  According to the present invention, since the detection light from the light source is incident on the optical component via the optical coupling means, the amount of light of the detection light is less attenuated than that on the optical component via the air. be able to. Therefore, it is possible to easily secure the necessary light quantity.

  Furthermore, the present invention is characterized by further comprising a relative displacement means for relatively displacing the light source and the waveguide path determining means with respect to one surface portion of the optical component.

  According to the present invention, the light source and the waveguide path determining means are relatively displaced with respect to one surface portion of the optical component by the relative displacement means. As a result, even if the optical component has a strong multi-coupling property and a short light guide distance, the incident position of the light for detection into the optical component is not limited. Defects in the shape of optical components can also be detected.

  According to the present invention, even if a film is provided on one surface portion of an optical component, detection light can be guided to the inside of the optical component. Even in the case of an optical component having a laminated structure, a defect in the optical component can be detected by guiding detection light to the inner layer.

  Also, since the detection light is incident from one surface part of the optical component, the incident position is changed even if the light attenuation rate is high due to multiple coupling and the detection light cannot be guided to the entire optical component. Thus, it is possible to detect a defect in the entire optical component. Therefore, even a large-sized optical component can detect a defect without inconvenience. That is, the defect of the optical component can be detected without being restricted by the size of the optical component. Therefore, the versatility of this defect detection method can be improved.

  Further, according to the present invention, the amount of attenuation can be reduced by making the light amount of the detection light incident through the optical coupling means rather than entering the optical component through the air. Further, by making the light incident through the optical coupling means, the waveguide path can be determined easily, and the present invention can be realized with a simple configuration. Therefore, the reproducibility of the present defect detection method can be simplified, and the number of work steps can be reduced.

  Furthermore, according to the present invention, since the optical component includes the step of inducing multiple coupling, the detection light incident from one surface portion of the optical component can be reliably guided to the inside of the optical component as described above. .

  Furthermore, according to the present invention, even when a gap is formed between the optical coupling means and the optical component, the detection light can be easily incident on the inside of the optical component. In addition, the detection light that enters the optical component also changes from the leaky wave that propagates without total reflection to the light that guides the layer to be detected while performing total reflection. Even when a gap is generated between the coupling means and the optical component, the detection light inside the optical component can be guided and a defect can be detected. As a result, a gap can be opened between the optical coupling means and the optical component to facilitate relative displacement.

  Further, according to the present invention, even if the optical component has a high multi-coupling property and a short light guide distance, the incident position of the detection light into the optical component is not limited, so that the defect detectable range is sequentially displaced. And defects in large optical components can also be detected.

  Furthermore, according to this invention, even if a film is provided in one surface part of an optical component, the light for a detection can be guide | induced to the inside of an optical component. Even in the case of an optical component having a laminated structure, a defect in the optical component can be detected by guiding detection light to the inner layer.

  Also, since the detection light is incident from one surface part of the optical component, the incident position is changed even if the light attenuation rate is high due to multiple coupling and the detection light cannot be guided to the entire optical component. Thus, it is possible to detect a defect in the entire optical component. Therefore, even a large-sized optical component can detect a defect without inconvenience. That is, the defect of the optical component can be detected without being restricted by the size of the optical component. Therefore, the versatility of this defect detection apparatus can be improved.

  Furthermore, according to the present invention, it is possible to easily secure the necessary light quantity. Further, by making the light incident through the optical coupling means, the waveguide path can be determined easily, and the present invention can be realized with a simple configuration.

  Further, according to the present invention, even if the optical component has a high multi-coupling property and a short light guide distance, the incident position of the detection light into the optical component is not limited, so that the defect detectable range is sequentially displaced. And defects in large optical components can also be detected.

  FIG. 1 is a perspective view showing an optical component defect detection apparatus 30 according to an embodiment of the present invention. FIG. 2 is a diagram illustrating the relationship between the optical component defect detection apparatus 30 and the optical component 35. An optical component defect detection device (hereinafter, also simply referred to as “defect detection device”) 30 includes a light irradiation means 31, a prism 32, a light detection unit 33, and a determination unit 34. The defect detection device 30 is a device that detects a defect 45 of an optical component 35 that is configured by laminating a plurality of light-transmitting layers, in this embodiment, six layers.

  The light irradiation means 31 includes a light source 36 and a lens 37 that condenses the light emitted from the light source 36, and the light source 36 directs detection light 38 toward one surface portion 35 a of the optical component 35 in the stacking direction. Exit. The detection light 38 emitted from the light source 36 is collected by the lens 37 and guided to the prism 32. The light source 36 is realized by a semiconductor laser, for example.

  The prism 32 has a function as a waveguide path determination means, and makes detection light 38 incident on one surface portion 35a of the optical component 35 from the light source 36 based on the refractive index of each layer of the optical component 35. The waveguide path of the working light 38 is determined. The prism 32 is an optical coupling means, and makes the detection light 38 from the light source 36 incident on one surface portion 35 a of the optical component 35. The prism 32 is arranged in the vicinity of one end surface of the optical component 35 in the stacking direction, and is detection light emitted from the light source 36 so as to induce multiple coupling in at least one of the layers constituting the optical component 35. 38 enters the optical component 35.

  For the prism 32, a glass material having a high refractive index such as LaSF03 is used. When a red semiconductor laser (wavelength 655 nm) is used as the light source, the refractive index of the prism is 1.8. The higher the refractive index material of the prism 32, the smaller the incident angle θ1, which is preferable for optical coupling.

  The light detection unit 33 is a light detection unit that detects light emitted from the optical component 35, and in the present embodiment, detects light emitted from the one surface 35a in the stacking direction of the optical component 35. The light detection unit 33 is realized by, for example, a light receiving element and a charge coupled device (abbreviated as CCD). The light detection unit 33 gives information based on the detected light to the determination unit 34.

  The determination unit 34 determines the presence or absence of the defect 45 of the optical component 35 based on the information given from the light detection unit 33. The determination unit 34 gives information indicating the determination result to a notification unit, for example, a display device or a sound generation unit, so that information based on the presence or absence of the defect 45 is notified.

  The optical component 35 is composed of a plurality of materials. In the present embodiment, the sheet-shaped material is laminated in the thickness direction. For example, when light is allowed to pass in the thickness direction, which is the lamination direction, To transmit only polarized light in one polarization direction. Hereinafter, in the present embodiment, for ease of description, the layer closest to one end in the stacking direction of the optical component 35 is referred to as a first layer 39, and sequentially toward the other end in the stacking direction, the second layer 40, The third layer 41, the fourth layer 42, the fifth layer 43, and the sixth layer 44 may be referred to. As an example of the refractive index of each layer, the refractive index of the first layer 39 is 1.51, the refractive index of the second layer 40 is 1.52, and the refractive index of the third layer 41 is 1. .505, the refractive index of the fourth layer 42 is 1.515, the refractive index of the fifth layer 43 is 1.5, and the refractive index of the sixth layer 44 is 1.52. When the defect 45 is present in the layer to which the detection light 38 is guided, refractive index, transmittance, and reflectance fluctuations are optically generated in the vicinity of the defect 45. When the detection light 38 passes through the defect 45, the detection light 38 is scattered in the vicinity of the defect 45. By detecting the scattered light by the light detection unit 33, the determination unit 34 determines that the defect 45 is a defect 45 when the light amount difference between the defect 45 and the surrounding area exceeds a predetermined value based on the detected scattered light. Thereby, the determination unit 34 can detect the defect 45.

  The principle of guiding the detection light 38 by causing multiple coupling to the second layer 40 of the optical component 35 as shown in FIG. 2 using the prism 32 will be described. First, the detection light 38 emitted from the light irradiation means 31 enters the first layer 39 of the optical component 35 from the prism 32 and reaches the second layer 40. When the detection light 38 from the light irradiation means 31 reaches the second layer 40 via the prism 32, the detection light 38 is set to an incident angle θ1 in the vicinity of the angle at which the light is totally reflected and guided through the second layer 40. 32. The incident angle θ1 is set in the vicinity of the angle at which the total reflection light is guided, particularly when the refractive index is equal among the first layer 39, the second layer 40, and the prism 32 at the time of incidence of the laminated optical component 35. This is because the angle at which the light is reflected and guided cannot be set. In other words, since the optical component 35 has a laminated structure, total reflection incidence is impossible except for special conditions such as a thin film device. Therefore, the detection light 38 is incident at an incident angle θ1 that does not totally reflect the second layer 40 as described above. When the incident angle θ1 is too far from the condition for totally reflecting the second layer 40, the multiple coupling inside the laminated optical component 35 cannot be used, so the incident angle θ1 to the prism 32 is totally reflected in the second layer 40. It is set near the angle of light.

  In each layer of the optical component 35, when there is in-layer non-uniformity that causes a decrease in light transmittance, multiple coupling can occur. In other words, the phase constant of the light changes with a plurality of combinations, and the light is divided into a plurality of different lights having different traveling directions.

  When multiple coupling occurs in the second layer 40, first, the incident angle θ1 to the prism 32 is close to the angle at which total reflection light is guided through the second layer 40, and the boundary between the prism 32 and the first layer 39, The detection light 38 is incident on the optical component 35 through the prism 32 at an angle that does not totally reflect at the boundary between the first layer 39 and the second layer 40. As a result, coupling between the light that has entered and a large number of mode groups that guide the second layer 40 easily occurs. In other words, under the above-described conditions, the phase constant of the light that has entered and the phase constant of each of the multiple lights that are guided through the second layer 40 are close to each other, and energy exchange between these lights is likely to occur.

  Since multiple coupling occurs due to non-uniformity in the second layer 40, for example, a part of the light passing through the optical component 35 by the first light guide path L1 as shown in FIG. Light having a phase velocity, in other words, light having a different propagation direction due to multiple coupling, is guided through the second layer 40 using the second light guide path L2 as an optical path.

  Below, the light guide conditions by the multiple coupling used in this embodiment will be specifically described. When each layer has a laminated structure satisfying the above refractive index relationship, the total reflection light is guided in the layer 40 because the incident angle θ2 at the boundary between the first layer 39 and the second layer 40 in FIG. Since this is the case of θ2C (83.4 degrees, derived from the total reflection conditional expression) or more, the incident angle θ1 to the prism 32 is set so that the incident angle θ2 is in this condition.

Next, a method for determining the incident angle θ1 to the prism 32 of the present embodiment will be described. An average diffusion angle (a value indicating how much the parallel light changes to diffused light due to non-uniformity in the layer) when the parallel light is incident on the laminated structure is a value Δθ that can be measured by entering the parallel light. Since the change of the propagation direction occurs within this angle, if the incident angle θ2 is equal to or larger than (θ2C−Δθ), light guide by multiple coupling can be generated. Further, as the incident angle θ2 is decreased, the transmittance at the boundary between the prism 32 and the first layer 39 is increased, so that multiple coupling is caused and the transmittance at the boundary between the prism 32 and the first layer 39 is also increased. Assuming that the incident angle θ2 to be secured is the incident angle θ2b, the incident angle θ2b is preferably a value obtained by subtracting the value of half of the average diffusion angle Δθ from the critical angle θ2C in the relationship of the following equation (1).
θ2b = θ2C−Δθ / 2 (1)
Therefore, when the average diffusion angle Δθ in the second layer 40 is 4 degrees, a preferable θ2 is 81.2 degrees.
When the prism refractive index is np and the refractive indexes of the first layer 39 and the second layer 40 are n39 and 40, respectively, the incident angle θ1 can be obtained by the following equation (2).
θ1 = asin (n40 · sin θ2b / np) (2)
That is, if 81.2 degrees is substituted for the incident angle θ2b, the incident angle θ1 to the prism 32 is 56.6 degrees.

  As described above, when the detection light 38 is incident on the prism 32 at an incident angle θ1 degree in the vicinity of the angle at which the light is totally reflected and guided in the second layer 40, multiple coupling is generated in the optical component 35. Since the light guided through the second layer 40 includes light whose phase changes, the amount of light for defect detection can be ensured.

  FIG. 3 is a flowchart illustrating a defect detection method for the optical component 35. In step a0, the optical component 35 is placed at a predetermined position, and the process proceeds to step a1. Step a1 is a waveguide path determination step, in which the detection light 38 is incident from one surface portion 35a of the optical component 35 based on the refractive index of each layer of the optical component 35, and the detection light 38 is guided. Determine the route. The detection light 38 enters the one surface portion 35a of the optical component 35 via the prism 32, and proceeds to step a2. In step a2, the light detection unit 33 detects scattered light emitted from the optical component 35, and the process proceeds to step a3. In step a3, the determination unit 34 determines the presence or absence of the defect 45 based on the scattered light intensity detected by the light detection unit 33, and proceeds to step a4. In step a4, the series of detection procedures from step a1 is terminated. The defect 45 is detected by such a detection procedure.

  As described above, in the defect detection device 30 according to the present embodiment, the detection light 38 is emitted from the light source 36, and the prism 32 uses the optical component 35 to the optical component based on the refractive index of each layer of the optical component 35. The detection light 38 is made incident on one surface portion 35 a of 35 to determine the waveguide path of the detection light 38. Thereby, the prism 32 can make the detection light 38 enter so as to induce multiple coupling in at least one of the layers constituting the optical component 35. Therefore, even if the incident angle θ1 of the detection light 38 to the prism 32 is incident at an angle where it is not totally reflected at the intermediate boundary, a part of the detection light 38 travels through the waveguide path due to total reflection by the action of multiple coupling. The phenomenon of changing to another light guide takes. In other words, a part of the detection light 38 is changed to another light guide, unlike the waveguide path when incident, due to the action of multiple coupling. As a result, part of the detection light 38 can be guided to the layer where the defect is to be detected. Even if the optical component 35 has a laminated structure in which the light guide layer is not near the surface, the defect 45 of the optical component 35 can be detected by guiding the detection light 38 to the light guide layer.

  Further, since the detection light 38 enters from the end face of the optical component 35 in the stacking direction, even if the light attenuation factor is high due to multiple coupling and the detection light 38 cannot be guided to the entire optical component 35, it is incident. The defect 45 of the entire optical component 35 can be detected by changing the position to be applied. Therefore, even if the optical component 35 has a large size, the defect 45 can be detected without any inconvenience. That is, the defect 45 of the optical component 35 can be detected without being restricted by the size of the optical component 35. Therefore, the versatility of this defect detection method and this defect detection apparatus can be improved.

  In addition, when the refractive indexes of the second layer 40 and the third layer 41 are not equal but close, there may be light propagating through both layers. Light that guides the layer 40 and the third layer 41 is generated, and the defect 45 can be detected.

  In the case of increasing the area of the laminated optical component 35, the material selected for the optical component 35 may not necessarily have a high transmittance with respect to the detection light 38 due to area restrictions. In addition, when the detection light 38 is guided to the laminated optical component 35 to detect the defect 45, there are a plurality of boundaries by laminating a plurality of layers. It is also necessary to reduce the number of reflections as much as possible to suppress the attenuation of the detection light 38 caused by the boundary. For this reason, the detection light 38 is not incident from the end face of the laminated optical component 35 as in the existing technology, but the detection light 38 is incident from the surface as in the above-described embodiment. The light can be guided efficiently, and the defect 45 of the optical component 35 can be detected.

  FIG. 4 is a diagram showing the relationship between the defect detection device 50 and the optical component 35 according to another embodiment of the present invention. The defect detection device 50 according to the present embodiment is similar to the defect detection device 30 of FIGS. 1 to 3 described above, and the configuration of the present embodiment is the same as the corresponding configuration of the defect detection device 30 described above. Reference numerals are attached, only different configurations are described, and description of similar configurations is omitted. In the present embodiment, the configuration of the optical component 35 is different.

  The optical component 35 is provided with a protective film 51 that covers one end portion in the stacking direction. The protective film 51 is a film having translucency, and protects the optical component 35 from being damaged by an external force. Even with such an optical component 35, the defect 45 can be detected.

  When the detection light 38 incident on the prism 32 is incident at an incident angle θ1 degree reaching the second layer 40 of the optical component 35, the light that has entered the second layer 40 passes through the second layer 40 by multiple coupling. It also changes to light that can be totally reflected and propagated. As a result, part of the detection light 38 propagates in the second layer 40, and if there is a defect 45 in a region where the light can reach, the light detection unit 33 detects the scattered light. be able to.

  As described above, the light guide method for detecting defects in the optical component 35 according to the present invention is a light guide method that causes multiple coupling. Therefore, even if the surface of the optical component 35 is protected by the protective film 51, the prism is used. 32, the defect 45 can be detected using the detection light 38 from the light irradiation means 31.

  FIG. 5 is a diagram showing the relationship between the defect detection device 60 and the optical component 35 according to still another embodiment of the present invention. The defect detection apparatus 60 of the present embodiment is similar to the defect detection apparatuses 30 and 50 of FIGS. 1 to 4 described above, and the configuration of the present embodiment corresponds to the defect detection apparatuses 30 and 50 described above. The same reference numerals as those in the configuration are attached, only different configurations are described, and description of similar configurations is omitted. In the present embodiment, the positions of the prisms 32 are different.

  As illustrated in FIG. 5, the optical component 35 and the prism 32 may not contact each other, and a gap may be generated between the optical component 35 and the prism 32. The angle at which the detection light 38 enters the gap through the prism 32 is set to an angle at which total reflection does not occur on the bottom surface of the prism 32. For example, in the prism 32 using the glass material LaSF03, since the incident angle θ for total reflection is 33.7 degrees and the average diffusion angle is 4 degrees, if the incident angle θ1 is 31 degrees, the present embodiment It is possible to guide the light into the laminated structure without causing total reflection at the bottom surface of the prism 32 in the form.

  The detection light 38 enters the second layer 40 of the optical component 35, and inside the optical component 35, a partial interlayer boundary, for example, the boundary between the second layer 40 and the first layer 39, and the second layer 40. The light is guided in a leaky wave state while passing through the boundary between the first layer 41 and the third layer 41. Since such a leaky wave has a phase constant close to that of light that is originally guided through the entire laminated structure (light that is guided back and forth between the first layer 39 and the sixth layer 44), several times of multiple coupling Is repeated between the first layer 39 and the sixth layer 44, the light that guides the second layer 40 inside the second layer 40 and multiple coupling can also occur. Therefore, a part of the incident detection light 38 can be changed from the leaky wave to the light guided through the second layer 40. If the reciprocation process is completed 10 times, the coupling proceeds sufficiently, so that the conversion from the leaky wave to the light guide into the second layer 40 is sufficiently generated.

  Due to such a phenomenon, even when there is a gap between the optical component 35 and the prism 32, the incident angle θ1 is a condition that allows the detection light 38 to reach the optical component 35, that is, a condition for guiding light with a leaky wave. Thus, the detection light 38 is incident on the optical component 35 by using the prism 32, and the light sufficiently guided can be secured. This can be used as light for defect detection.

  As described above, in the defect detection device 60 according to the present embodiment, the prism 32 and the optical component are made to enter the detection light 38 so as to induce the leaky wave into the optical component 35. Even if a gap is formed between the optical component 35 and the detection light 38, the detection light 38 can be easily incident on the optical component 35 at an angle that is not totally reflected by the bottom surface of the prism 32.

  In addition, the detection light 38 that has entered the optical component 35 partially changes from a leaky wave, which is a light that propagates without being totally reflected, to a light that guides a layer where a defect is to be detected while repeating multiple coupling. Therefore, the defect 45 can be detected.

  In addition, since the defect 45 can be detected even if a gap is formed between the prism 32 and the optical component 35, the relative displacement between the prism 32 and the optical component 35 can be facilitated. Therefore, the reproducibility of the defect detection method and the defect detection apparatus can be simplified, and the number of work steps can be reduced.

  FIG. 6 is a diagram showing the relationship between the defect detection apparatus 70 and the optical component 35 according to still another embodiment of the present invention. The defect detection device 70 of the present embodiment is similar to the defect detection devices 30, 50, 60 of FIGS. 1 to 5 described above, and the configuration of the present embodiment includes the defect detection devices 30, 50, 60 described above. The same reference numerals are assigned to the corresponding components in 60, and only different components will be described, and description of similar components will be omitted. In the present embodiment, the defect detection device 70 is further configured to include a moving unit 71, and the light source 36 and the prism 32 can be relatively displaced by the moving unit 71 with respect to the one surface portion 35 a of the optical component 35. Is done.

  The defect detection device 70 further includes a moving means 71 for moving the light source 36 and the prism 32. The moving means 71 moves the prism 32 substantially in parallel to the light guiding direction when the light is guided to the optical component 35 (the term “substantially parallel” includes parallel). For example, the position is moved from the position indicated by the broken line in FIG. 6 to the position indicated by the solid line. The light detection unit 33 is configured to move in conjunction with the prism 32. The light detection unit 33 can be miniaturized by interlocking with the prism 32, and the entire configuration of the defect detector becomes simpler.

  As described above, in the present embodiment, the prism 32 is the direction in which the detection light 38 is emitted in the present embodiment with respect to the one surface portion 35a of the optical component 35, and the direction intersecting the stacking direction. The component can be displaced. As a result, even if the optical component 35 has a high multi-coupling property and a short light guide distance, the incident position of the detection light 38 into the optical component 35 is not limited. The defect 45 of the large optical component 35 can also be detected.

  Each of the embodiments described above is merely an example of the present invention, and the configuration can be changed within the scope of the present invention. Further, for example, the above-described embodiments may be appropriately combined.

  In each of the above-described embodiments, the detection light 38 is incident on the optical component 35 via the prism 32, but the detection light 38 from the light source 36 is directly passed through the optical component 35 without passing through the prism 32. You may comprise so that it may inject into. When the detection light 38 is incident on the optical component 35 without passing through the prism 32, the light amount and the incident angle θ1 of the detection light 38 are appropriately selected.

It is a perspective view which shows the defect detection apparatus 30 of the optical component of one Embodiment of this invention. FIG. 3 is a diagram illustrating a relationship between an optical component defect detection apparatus 30 and an optical component 35; 3 is a flowchart showing a method for detecting a defect in an optical component 35. It is a figure which shows the relationship between the defect detection apparatus 50 and the optical component 35 of other form of implementation of this invention. It is a figure which shows the relationship between the defect detection apparatus 60 of the further another form of implementation of this invention, and the optical component 35. FIG. It is a figure which shows the relationship between the defect detection apparatus 70 of the further another form of implementation of this invention, and the optical component 35. FIG. It is a perspective view which shows the defect detection apparatus 1 of the transparent substrate of the 1st prior art. It is a block diagram which shows schematically the control system of the defect detection apparatus 10 of the 2nd prior art. It is a front view which shows the relationship between the prism coupler 21 used for the defect detection apparatus of a 3rd prior art, and a board | substrate.

Explanation of symbols

30, 50, 60, 70 Optical component defect detection device 32 Prism 33 Photodetection unit 34 Judgment unit 35 Optical component 36 Light source 38 Detection light 45 Defect 51 Protective film 71 Moving means

Claims (8)

In a method for detecting a defect in an optical component in which a plurality of layers are laminated,
An optical component defect comprising a waveguide path determining step for determining a waveguide path of detection light by making detection light incident from one surface portion of the optical component based on the refractive index of each layer Detection method.   The optical component defect detection method according to claim 1, wherein the waveguide path determination step includes a step of causing detection light to be incident on the one surface portion from a light source through an optical coupling unit.   3. The optical component defect detection method according to claim 1, wherein the waveguide path determination step includes a step of inducing multiple coupling in the optical component.   The optical component defect detection method according to claim 1, wherein the waveguide path determination step includes a step of inducing a leaky wave in the optical component.   The optical component defect detection method according to claim 1, further comprising a relative displacement step of relatively displacing the light source with respect to one surface portion of the optical component. In an apparatus for detecting a defect in an optical component in which a plurality of layers are laminated,
A light source;
An optical system comprising: a waveguide path determining unit that determines the waveguide path of the detection light by causing detection light to enter the surface of the optical component from the light source based on the refractive index of each layer. Component defect detection device. The waveguide path determining means includes optical coupling means,
7. The optical component defect detection apparatus according to claim 6, wherein the detection light from the light source is incident on the optical component through an optical coupling means.   The optical component defect detection device according to claim 6, further comprising a relative displacement unit that relatively displaces the light source and the waveguide path determination unit with respect to one surface portion of the optical component.

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