JP2015081779A - Detection method for light and measurement method for optical transmission loss - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a detection method for light, by which intensity of light to be used for measurement of a transmission loss of light per unit length of a waveguide can be easily detected, and a measurement method for an optical transmission loss by which a transmission loss of light per unit length of a waveguide can be easily calculated based on the above intensity.SOLUTION: The detection method for light comprises measuring intensity of light to be used for measurement of a transmission loss of light in a waveguide. The detection method for light includes: a first step of preparing an optical waveguide 8A in which cores 84a to 84d having different lengths from one another are arranged in parallel to one another; and a second step of inputting light to each one end of the cores 84a to 84d, allowing the light to exit from each other end of the cores 84a to 84d, and receiving the output light to detect the intensity.

Description

  The present invention relates to a light detection method and a light transmission loss measurement method.

  In recent years, optical communication using optical signals to transfer data has become increasingly important. In such optical communication, an optical waveguide is used as a means for guiding light propagating a signal from one point to another point.

  The optical waveguide is composed of, for example, a core layer and a pair of clad layers provided on both sides of the core layer. The core layer has a linear core portion and a clad portion that transmit light, and these are alternately arranged.

  In general, in an optical waveguide, the insertion loss increases as the length of the core portion increases. A cutback method is known as a method for measuring the transmission loss of light per unit length by using this (for example, see Non-Patent Document 1).

  The cutback method described in Non-Patent Document 1 includes the following steps (1) to (4).

(1) The light is incident from one end of the optical waveguide, the intensity of the light emitted from the other end is measured by an optical power meter, and the insertion loss is calculated.
(2) One end of the optical waveguide is cut to form an optical waveguide shorter than the optical waveguide in (1).

  (3) Light is incident from one end of the optical waveguide obtained in (2), the intensity of the light emitted from the other end is measured by an optical power meter, and the insertion loss is calculated.

  (4) Based on the difference in length of the optical waveguide in the steps (1) and (3) and the difference in insertion loss obtained in the steps (1) and (3), per unit length of the optical waveguide. Calculate the optical transmission loss.

  However, in order to calculate the accurate transmission loss of light, it is necessary to repeat the above steps (1) to (4) many times and calculate the transmission loss based on the measurement results. In addition, the cost increases.

Japan Electronic Circuits Association, JPCA Standard “Testing Method for Polymer Optical Waveguide” [online], June 2008, [February 14, 2013 search], Internet <URL: http: // www. jpca.net/hikari/pdf/jpca-pe02-05-01s-2008.pdf>

  An object of the present invention is to provide a light detection method capable of easily detecting the intensity of light used for measuring the transmission loss of light per unit length of the light guide and the light per unit length of the light guide based on the intensity. An object of the present invention is to provide an optical transmission loss measuring method capable of easily calculating transmission loss.

Such an object is achieved by the present inventions (1) to (11) below.
(1) A method for measuring the intensity of light used for measuring light transmission loss of a light guide,
A first step of preparing a light guide path object in which a plurality of core portions each having a different length are provided;
And a second step of detecting the intensity of light incident on one end of each core part, emitting light from the other end of each core part, and receiving the emitted light. Detection method.

  (2) The unit length of the light guide object based on the intensity of the emitted light of each core part detected in the second step by the light detection method according to claim 1 and the length of each core part An optical transmission loss measurement method further comprising a third step of calculating a transmission loss of light per unit.

  (3) The light guide path subject has a plurality of core portions each having the same length, and at least one end surface of the light guide path base material having a rectangular shape in plan view has at least one end surface of the light guide path base. The optical transmission loss measuring method according to the above (2), wherein the optical transmission loss measurement is performed so as to form an inclined surface inclined with respect to the longitudinal direction of the plurality of core portions of the material.

  (4) The optical transmission loss measuring method according to (3), wherein in the second step, light is incident from the inclined surface side.

  (5) The optical transmission loss measuring method according to (3) or (4), wherein the inclined surfaces are provided at both ends of the light guide path subject.

  (6) The optical transmission loss measurement method according to (5), wherein each of the inclined surfaces is inclined in different directions with respect to a longitudinal direction of the plurality of core portions.

  (7) The optical transmission loss measuring method according to any one of (3) to (6), wherein the inclined surface is inclined by 5 to 65 degrees with respect to an extending direction of the core portions.

  (8) The optical transmission loss measuring method according to any one of (3) to (7), wherein the light guide path subject is processed by cutting the light guide path base material.

  (9) The optical transmission loss measuring method according to any one of (2) to (8), wherein in the second step, light is incident on the respective core portions from a single light source that emits light. .

  (10) In the third step, an end face from which the light of each core part is emitted is imaged, and a luminance difference between the images of the emitted light in the obtained image and a difference in length of the core parts are obtained. The light transmission loss measurement method according to any one of (2) to (9), wherein a light transmission loss per unit length of the light guide path subject is calculated based on the above.

  (11) The optical transmission loss measurement method according to (10), wherein in the third step, a plurality of images are captured while moving in parallel with the end face from which the light of each core portion is emitted.

  According to the present invention, it is possible to easily detect the intensity of light used for measuring the transmission loss of light per unit length of the light guide, and to transmit light per unit length of the light guide based on the intensity. Loss can be easily calculated.

It is a perspective view which shows the measuring apparatus used for 1st Embodiment of the optical detection method and optical transmission loss measuring method of this invention. It is a schematic block diagram of the measuring apparatus shown in FIG. It is a perspective view of the light guide path base material before processing the light guide object shown in FIG. It is a perspective view of the light guide path base material shown in FIG. It is a figure which shows the detection result by the measuring apparatus shown in FIG. It is a perspective view which shows the measuring apparatus used for 2nd Embodiment of the optical detection method and optical transmission loss measuring method of this invention. It is a schematic block diagram which shows the measuring apparatus used for 3rd Embodiment of the optical detection method and optical transmission loss measuring method of this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a detection apparatus and a detection method of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

<First Embodiment>
FIG. 1 is a perspective view showing a measuring apparatus used in the first embodiment of the light detection method and the optical transmission loss measuring method of the present invention, FIG. 2 is a schematic configuration diagram of the measuring apparatus shown in FIG. 1, and FIG. 4 is a perspective view of the light guide path base material before processing the light guide path specimen shown in FIG. 1, FIG. 4 is a perspective view of the light guide path base material shown in FIG. 1, and FIG. 5 is a detection result by the measurement apparatus shown in FIG. FIG.

  In the following, for convenience of explanation, the upper side of FIGS. 1 to 4 is referred to as “upper” and the lower side is referred to as “lower”. Moreover, the right side of FIGS. 1-4 is called "one end", and the left side is called "other end".

  First, the measurement apparatus 1 used in the light detection method and the optical transmission loss measurement method of the present invention will be described.

  A measuring apparatus 1 shown in FIG. 1 is an apparatus that detects the intensity of light emitted from a light guide and calculates (measures) an optical transmission loss per unit length of the light guide based on the detection result. Here, examples of the light guide used for detection and measurement by the measuring apparatus 1 include an optical fiber and an optical waveguide, and the form thereof is not particularly limited. However, in the following description, for convenience of explanation, the light guide is a light guide. The description will be made assuming that the waveguide is a waveguide. In addition, the description about the optical waveguide mentioned later is applicable to an optical fiber as it is.

  The measuring apparatus 1 includes a stage 2, a light source 3, a camera 4, and a control unit 100. This measuring apparatus 1 has optical waveguides (light guide path covers) that are processed such that their lengths are equal to each other and the optical waveguides (light guide path base materials) 8 having parallel core portions 84a to 84d are different from each other. Specimen) Light is incident on one end of 8A and the intensity of outgoing light emitted from the other end is detected. Based on the intensity, light propagation loss per unit length of optical waveguide 8A (hereinafter simply referred to as “transmission loss”) ) Is calculated.

Hereinafter, the structure of each part of the measuring apparatus 1 of this invention is demonstrated.
(Stage 2)
As shown in FIG. 1, the stage 2 is composed of a plate member and has a function of stably supporting the optical waveguide 8A and the like.

  Moreover, it is preferable that an adhesive layer is provided on the upper surface 21 of the stage 2 at a portion that contacts the optical waveguide 8A (not shown). Thereby, the optical waveguide 8A can be easily fixed to the stage 2 through the adhesive layer.

  As a constituent material of such an adhesive layer, for example, silicone-based adhesive, polyvinyl chloride-based adhesive, polyester-based adhesive, elastomer-based adhesive, rubber-based adhesive, acrylic resin-based adhesive, polyvinyl ether resin-based An adhesive etc. are mentioned, Among these, the 1 type, or 2 or more types of mixture is used. As the adhesive layer, for example, a magic resin (manufactured by Daisho Electronics), a bonding sheet, a dicing film, or the like can be used.

  In the present embodiment, the method of fixing the optical waveguide 8A to the stage 2 uses an adhesive layer. However, for example, a method of pressing against the stage 2 with an urging member such as a leaf spring, or the optical waveguide 8A There may be a method of providing a slit to be inserted, energizing from the inner side surface of the groove in the width direction of the optical waveguide, and holding it.

  Examples of the material constituting the stage 2 include various metals, various glasses, various ceramics, and various resins.

(Light source 3)
As shown in FIGS. 1 and 2, the light source 3 is provided on one end side of the stage 2, that is, on one end side of the optical waveguide 8A. The light source 3 emits light so that the light is incident on the core portions 84a to 84d in a lump.

  This light source 3 is comprised by light emitting elements, such as a light emitting diode (LED), various lamps, and various laser light sources, for example. Further, the light source 3 may be a complex (unit) in which, for example, a bandpass filter, a collimating lens, a polarizer, and the like are incorporated.

  The maximum peak wavelength of the emission spectrum of the light emitted from the light source 3 is preferably about 200 to 1300 nm, and more preferably about 300 to 1100 nm. The light emitted from the light source 3 is preferably monochromatic light. As a result, blurring or the like of the image due to mixing of wavelengths is suppressed, and thus the image discrimination of the core portions 84a to 84d on the image is improved.

  The light source 3 has a built-in driver 30 that controls the characteristics of the emitted light. The driver 30 is electrically connected to a control unit 100 described later. Based on the signal from the control unit 100, the driver 30 controls the light amount, wavelength, presence / absence of emission, and the like.

(Camera 4)
As shown in FIGS. 1 and 2, the camera 4 is provided on the other end side of the optical waveguide 8 </ b> A and the stage 2. The camera 4 images the other end surface of the optical waveguide 8A from the other end side of the core portions 84a to 84d.

  As the camera 4, for example, a CCD (Charge Coupled Device) camera can be used. Thereby, a light and shade (light / dark) image can be obtained. Therefore, in the image captured by the camera 4, an image of each part of the core parts 84a to 84d is obtained by this brightness difference, and the position of the maximum brightness value in the image of the emitted light of the core parts 84a to 84d is specified. Can do.

  In addition to the CCD, the camera 4 may use an imaging means such as a CMOS, an imaging plate, or a film. The camera 4 may be a complex (unit) in which, for example, a band-pass filter, a collimating lens, a polarizer, and the like are incorporated.

  As shown in FIG. 2, the camera 4 captures an image by the linear actuator 40 while moving in parallel along the other end surface of the optical waveguide 8A. By capturing a plurality of images while the camera 4 is moving, the camera 4 can ensure a wide field even when capturing at a relatively high magnification. Therefore, the resolution of each image is improved. As a result, the detection position accuracy of the light intensity of the core portions 84a to 84d in the image is improved.

  The linear actuator 40 moves the camera 4 based on a signal from the control unit 100 described later. Then, the plurality of images captured by the camera 4 are transmitted to the control unit 100, and are synthesized and analyzed based on the position information of the linear actuator 40 as necessary.

(Control unit 100)
As shown in FIG. 2, the control unit 100 has a function of controlling each unit of the detection device 1. The control unit 100 includes light detection means 5 and light transmission loss calculation means 6. Further, as described above, the control unit 100 is electrically connected to the linear actuator 40 that moves the driver 30 and the camera 4. Thereby, the control part 100 can synchronize the drive of the light source 3 and the camera 4. FIG.

  The control unit 100 further includes a calculation unit (not shown) that performs calculation processing such as image analysis and matching. Specific examples of the calculation unit include an LSI, an IC, a CPU, an MPU, and a personal computer. Further, if necessary, an input unit (such as a keyboard) for inputting setting values and the like, a storage unit (RAM, ROM, etc.) for storing setting values and programs, and the like may be provided.

  The control unit 100 may perform image processing on the image captured by the camera 4 as necessary. Examples of this image processing include binarization processing, noise removal, pattern matching, and the like. Thereby, the detection precision of the emitted light of the core parts 84a-84d can be improved.

  The light detection means 5 is software built in the control unit 100. The light detection means 5 receives the light emitted from the core portions 84a to 84d and detects the intensity. Specifically, the intensity is detected based on the luminance value of the image of the light emitted from the cores 84a to 84d in the image captured by the camera 4.

  The optical transmission loss calculation means 6 is software built in the control unit 100. The optical transmission loss calculation means 6 is based on the length (difference in length) of the core portions 84a to 84d and the intensity of the emitted light from the core portions 84a to 84d detected by the light detection means 5. Calculate the optical transmission loss per unit length.

  The light detection means, the optical transmission loss calculation means, and the coupling loss estimation means of each embodiment are software built in the control unit, but the present invention is not limited to this, and hardware having similar functions Etc.

(Optical waveguide 8)
The overall shape (rectangular shape) of the optical waveguide 8 shown in FIG.

  The optical waveguide 8 includes a clad layer (first clad layer (clad part)) 83a, a core layer 82, and a clad layer (second clad layer (clad part)) 83b. They are laminated in order from the bottom.

  The core layer 82 includes a plurality of (four in the present embodiment) core portions (waveguide channels) 84a, 84b, 84c, and 84d, and a plurality (five in the present embodiment). Side cladding portions (cladding portions) 85 a, 85 b, 85 c, 85 d, and 85 e are provided, and these are alternately arranged in the width direction of the optical waveguide 8. Thus, the optical waveguide 8 is a multi-channel type having a plurality of core portions.

  The core portions 84a to 84d are made of a material having a higher refractive index than the side clad portions 85a to 85e, and are also made of a material having a higher refractive index than the cladding layers 83a and 83b.

  The constituent materials of the core portions 84a to 84d and the side clad portions 85a to 85e are not particularly limited.

  Cladding layers 83a and 83b are disposed on both surfaces of the core layer 82 shown in FIG. The clad layers 83 a and 83 b constitute clad portions located below and above the core layer 82, respectively, and are in contact with the core layer 82. Thereby, core part 84a-84d becomes a structure by which all the outer surfaces are surrounded by a clad part, respectively. Therefore, each of the core portions 84a to 84d functions as a light guide path.

(Optical waveguide 8A)
The optical waveguide 8A is a measurement material obtained by cutting one end portion of the optical waveguide 8 described above obliquely with respect to the longitudinal direction of the core portions 84a to 84d. As a result, the lengths of the core portions 84a to 84d of 8A are different from each other.

(Optical detection method and optical transmission loss measurement method)
Next, a light detection method and a light transmission loss measurement method will be described. The light detection method and the optical transmission loss measurement method include: [1] a preparation step of processing the optical waveguide 8 to prepare 8A; [2] a light emission step of emitting light so that light enters the optical waveguide 8A; [3] An imaging process for imaging (receiving) light emitted from the optical waveguide 8A, [4] a light detection process for detecting the intensity of light emitted from the optical waveguide 8A, and [5] obtained in the light emission process. It has an optical transmission loss calculation step of calculating an insertion loss from the intensity of the emitted light and calculating a transmission loss based on the calculation result and the length of the core portions 84a to 84d. Hereinafter, each process will be described sequentially.

[1] Preparation step (first step)
First, one end portion of the optical waveguide 8 is cut and processed obliquely with respect to the longitudinal direction of the core portions 84a to 84d. At this time, the inclined surface 80 which is the cut end surface is preferably inclined by 5 to 65 ° with respect to the longitudinal direction (extending direction) of the core portions 84a to 84d, and is inclined by 10 to 55 °. More preferably.

  Thereby, while being able to obtain the core parts 84a-84d from which length differs reliably, the light from the light source 3 can be reliably entered in the core parts 84a-84d.

  The processing method of the optical waveguide 8 is not particularly limited, and for example, a cutting method using a dicing saw, a cutter, or the like can be used. Moreover, you may grind the inclined surface 80 as needed.

Next, the optical waveguide 8A is fixed to the stage 2 (see FIG. 1).
[2] Light emitting step (second step)
Next, as shown in FIGS. 1 and 2, the driver 30 of the light source 3 is driven so that the light is incident on the core portions 84a to 84d of the optical waveguide 8A. At this time, the light emitted from the light source 3 enters the inclined surface 80. Since the inclined surface 80 is inclined with respect to the core portions 84 a to 84 d, the area of one end surface of the core portions 84 a to 84 d on the inclined surface 80 is one of the core portions 84 a to 84 d on one end surface of the optical waveguide 8. It is larger than the area of the end face. Thereby, the light radiate | emitted from the light source 3 can inject into core part 84a-84d more reliably.

[3] Image pickup (light reception) step Next, the linear actuator 40 is driven to move the camera 4 along the other end face of the optical waveguide 8A, and take a plurality of images of the other end faces of the core portions 84a to 84d. In the present embodiment, it is possible to easily acquire a plurality of spatially continuous images by a simple operation in which the linear actuator 40 moves the camera 4 in the width direction of the optical waveguide 8A.

[4] Light detection step (second step)
Next, the light detection means 5 detects (measures) the luminance (intensity) of the image of the emitted light from the core portions 84a to 84d in the image obtained in the imaging process.

  Note that the measured value may be the maximum value of luminance in the images of the emitted lights of the core portions 84a to 84d, the average value of luminance in the images, or the total sum of luminance in the images.

  Furthermore, as long as it is included in the image, each luminance of the plurality of core portions can be detected collectively. In that case, the time required for the luminance measurement per core part can be shortened.

  Also, abnormalities in manufacturing of each core part can be detected by the shape of the image of the emitted light from each core part.

[5] Optical transmission loss calculation step (third step)
Next, the optical transmission loss calculating means 6 first calculates the insertion loss Li (dB) of the core portions 84a to 84d, respectively. Specifically, the optical transmission loss calculation means 6 determines the intensity of the light emitted from the light source 3 and the intensity of the light emitted from the light source 3 based on the detection result of the intensity of light emitted from the core 84a obtained in the step [4]. The insertion loss Li1 is calculated, and the insertion loss Li2 of the core portion 84b is calculated based on the detection result of the intensity of the emitted light of the core portion 84b obtained in [4] and the intensity of the light emitted from the light source 3. The insertion loss Li3 of the core portion 84c is calculated based on the detection result of the intensity of the emitted light from the core portion 84c obtained in [4] and the intensity of the light emitted from the light source 3, and obtained in [4]. The insertion loss Li4 of the core portion 84d is calculated based on the detection result of the intensity of the emitted light from the core portion 84d and the intensity of the light emitted from the light source 3.

  These insertion losses Li1 to Li4 can be obtained by the following formula (1) or formula (2).

  Insertion loss Li (dB) = incident light intensity (dBm) −emitted light intensity (dBm) (1) (when the unit of light intensity is dBm)

  Insertion loss Li (dB) = − 10 · log {Intensity of incident light (mW) / Intensity of outgoing light (mW)} (2) (when the intensity of light is mW)

  Next, the transmission loss Lt is calculated by the optical transmission loss calculation means 6. The transmission loss Lt is calculated based on the insertion losses Li1 to Li4 and the lengths L1 to L4 of the respective core portions, and can be obtained by the following equation (3).

Transmission loss Lt (dB / cm) = change amount of insertion loss Li (difference of insertion loss Li of each core part) ΔLi (dB) / difference of length of each core part ΔL (cm) Equation (3)
Specifically, the length of each core part (the length L1 of the core part 84a, the length L2 of the core part 84b, the length L3 of the core part 84c, and the length L4 of the core part 84d) is taken as the horizontal axis, The insertion loss Li1 to Li4 of the core part is plotted as the vertical axis, and the slope is obtained by the least square method. This inclination becomes the transmission loss Lt (dB / cm) (see FIG. 5).

  By performing the above calculation by the optical transmission loss calculating means 6, the optical waveguide 8A is based on the intensity of the emitted light of the core portions 84a to 84d detected in the second step and the length of the core portions 84a to 84d. The transmission loss Lt can be calculated.

  Conventionally, the method for calculating the transmission loss of the optical waveguide has undergone the following steps (1) and (2).

(1) The light is incident from one end of the optical waveguide, the intensity of the light emitted from the other end is measured by an optical power meter, and the insertion loss is calculated.
(2) One end of the optical waveguide is cut to form an optical waveguide shorter than the optical waveguide in (1).

  After repeating the steps (1) and (2) many times, the transmission loss was calculated based on the measurement result at that time. However, this method is very time-consuming because it is necessary to repeat the steps (1) and (2) many times.

  On the other hand, according to the light detection method and the optical transmission loss measurement method of the present invention, the lengths L1 to L4 of the core portions are respectively set by the very simple processing of once cutting the optical waveguide 8 as described above. By forming different optical waveguides 8A and using them, the measurement of the transmission loss Lt can be greatly simplified. That is, the transmission loss Lt of the optical waveguide 8A can be easily calculated only by detecting the intensity of light propagating through the core portions 84a to 84d having different lengths in one waveguide. The present invention is useful.

  The insertion loss of the optical waveguide (light guide waveguide base material) 8 is measured in advance, and the transmission loss is corrected by correcting the insertion losses Li1 to Li4 of the core portions 84a to 84d in the step [5] based on the measurement result. Lt can be measured more accurately.

  Further, the insertion loss Li of each core portion of the optical waveguide 8 is measured in advance, and the measurement result is added to the calculation result of the transmission loss Lt, so that the shift (error) of the transmission loss Lt due to the individual difference of the core portions 84a to 84d. ) Can be suppressed. Thereby, a more accurate transmission loss Lt can be obtained.

Second Embodiment
FIG. 6 is a perspective view showing a measuring apparatus used in the second embodiment of the light detection method and the optical transmission loss measurement method of the present invention.

  Hereinafter, the second embodiment of the detection apparatus and the detection method of the present invention will be described with reference to this figure, but the description will focus on differences from the above-described embodiment, and the description of the same matters will be omitted.

  The present embodiment is the same as the first embodiment except that the configuration of the optical waveguide (light guide subject) is different.

  The optical waveguide 8B is formed by cutting the other end portion of the optical waveguide 8A described above in a direction intersecting with the longitudinal direction of the core portions 84a to 84d (a direction different from the inclined surface 80). is there.

  The inclined surface 80B which is the cut end surface is preferably inclined by 5 to 65 ° with respect to the longitudinal direction (extending direction) of the core portions 84a to 84d, and is inclined by 10 to 55 °. More preferred.

  According to this embodiment, the difference in length of each of the core portions 84a to 84d becomes larger than when only one end is processed as in the first embodiment. Therefore, the detection result and the measurement result obtained by the light detection method and the optical transmission loss measurement method of the present invention are more accurate.

<Third Embodiment>
FIG. 7 is a schematic configuration diagram showing a measurement apparatus used in the third embodiment of the light detection method and the optical transmission loss measurement method of the present invention.

  Hereinafter, the third embodiment of the detection apparatus and the detection method of the present invention will be described with reference to this figure, but the description will focus on differences from the above-described embodiment, and the description of the same matters will be omitted.

  This embodiment is the same as the first embodiment except that the configuration of the camera (imaging means) is different.

  As shown in FIG. 7, the measuring apparatus 1 'according to the present embodiment includes four cameras 4a, 4b, 4c, and 4d. The cameras 4a to 4d are provided along the width direction of the optical waveguide 8A so as to face the other end surfaces of the optical waveguide 8A. The cameras 4a to 4d are electrically connected to the control unit 100, respectively. Thereby, the light source 3 and the cameras 4a to 4d can be synchronized.

  By providing the four cameras 4a to 4d in this manner, the linear actuator 40 can be omitted, and the configuration of the detection device 1 'is relatively simple. Further, the time required for the movement of the camera 4 by the linear actuator 40 can be omitted. It is possible to eliminate the positional shift caused by the driving error of the linear actuator 40.

  As described above, the optical detection method and the optical transmission loss measurement method of the present invention have been described with respect to the illustrated embodiment. However, the present invention is not limited to this, and is a combination of configurations (features) of the respective embodiments. There may be. Moreover, arbitrary configurations (features) may be added.

  In each embodiment, the intensity of the emitted light from each core part is detected in the second step. However, the present invention is not limited to this, and the intensity of the emitted light from one core part may be detected. In this case, core portions other than the one core portion may be estimated based on acquired information.

  In the first embodiment and the second embodiment, the camera is moved by a linear actuator. However, the present invention is not limited to this, and any apparatus and method may be used as long as it has a function of moving the camera. It may be used.

  In the second embodiment, four cameras are installed. However, the present invention is not limited to this, and four or less cameras or four or more cameras may be installed.

DESCRIPTION OF SYMBOLS 1, 1 'Measuring apparatus 2 Stage 21 Upper surface 3 Light source 30 Driver 4, 4a, 4b, 4c, 4d Camera 40 Linear actuator 5 Optical detection means 6 Optical transmission loss calculation means 8 Optical waveguide (light guide path base material)
8A, 8B Optical waveguide (light guide object)
80, 80B inclined surface 82 core layer 83a cladding layer (first cladding layer (cladding portion))
83b Cladding layer (second cladding layer (cladding portion))
84a, 84b, 84c, 84d Core part (waveguide channel)
85a, 85b, 85c, 85d, 85e Side cladding (cladding)
100 Control unit L1, L2, L3, L4 Length Li1, Li2, Li3, Li4 Insertion loss Lt Transmission loss

Claims (11)

A method of measuring the intensity of light used to measure light transmission loss in a light guide,
A first step of preparing a light guide path object in which a plurality of core portions each having a different length are provided;
And a second step of detecting the intensity of light incident on one end of each core part, emitting light from the other end of each core part, and receiving the emitted light. Detection method.   The per-unit length of the light guide path subject based on the intensity of the emitted light of each core part detected in the second step by the light detection method according to claim 1 and the length of each core part. An optical transmission loss measurement method further comprising a third step of calculating an optical transmission loss.   The light guide path subject has a plurality of core portions each having the same length, and a light guide path base material having a rectangular shape in plan view, at least one end surface of the light guide path base material is at least one end surface of the light guide path base material. The optical transmission loss measurement method according to claim 2, wherein the optical transmission loss measurement method is performed so as to form an inclined surface inclined with respect to the longitudinal direction of the plurality of core portions.   The optical transmission loss measurement method according to claim 3, wherein in the second step, light is incident from the inclined surface side.   The optical transmission loss measurement method according to claim 3 or 4, wherein the inclined surfaces are provided at both ends of the light guide path subject.   The optical transmission loss measurement method according to claim 5, wherein the inclined surfaces are inclined in different directions with respect to the longitudinal direction of the plurality of core portions.   The optical transmission loss measuring method according to claim 3, wherein the inclined surface is inclined by 5 to 65 ° with respect to the extending direction of the core portions.   The optical transmission loss measurement method according to claim 3, wherein the light guide path subject is processed by cutting the light guide path base material.   9. The optical transmission loss measuring method according to claim 2, wherein in the second step, light is incident on the respective core portions from one light source that emits light at a time.   In the third step, the end surface from which the light of each core part is emitted is imaged, and based on the luminance difference between the images of the emitted light in the obtained image and the difference in length of the core parts, The optical transmission loss measurement method according to claim 2, wherein a transmission loss of light per unit length of the light guide path subject is calculated.   The optical transmission loss measurement method according to claim 10, wherein in the third step, a plurality of images are captured while moving in parallel with the end face from which the light of each core part is emitted.

Images