Optical monitor device and optical intensity measurement method

Abstract

The purpose of the present disclosure is to achieve an optical monitor device capable of measuring the light intensity of an optical signal incident on a multicore optical fiber irrespective of the polarization state of the optical signal.　The optical monitor device according to the present disclosure detects the intensify of light propagating through a plurality of optical fibers, and comprises a plurality of branch parts and a plurality of optical sensors. The plurality of optical sensors have, two-dimensionally arrayed, a greater number of pixels than the number of the plurality of optical fibers, detect the light intensity of each pixel corresponding to an incidence position in an incidence region, calculate, for each pixel corresponding to an incidence position in the incidence region, the total of the light intensities detected by the plurality of optical sensors, and use the calculated total of the light intensities of the pixels to calculate the intensity of light propagating through at least any one optical fiber from among the plurality of optical fibers.

Description

[Technical Field]

[0001] The present disclosure relates to an optical monitoring device, and more particularly to an optical monitoring device for detecting the intensity of light in an optical transmission device or the like and feeding back the detection result to other components. [Background technology]

[0002] In recent years, the increase in Internet traffic has created a strong demand for increased communication capacity in communication systems. To achieve this, optical fiber communication systems are used in access networks between communication centers and user homes, and in core networks connecting communication centers. In optical fiber communication, the detection of the optical power propagating through optical fibers is often used to control communication and verify the health of equipment. For example, in access networks, test light is propagated through optical fibers, and the optical power is detected to verify the loss and health of the optical fiber, as well as the symmetry and connection of the core fibers. In addition, WDM (Wavelength Division Multiplex) transmission used in core networks requires monitoring of optical power for feedback control.

[0003] Optical power monitoring in access networks employs a technology that uses an optical coupler to split light at a fixed splitting ratio for each optical fiber core using two parallel waveguides (see, for example, Patent Document 1), which enables measurements of optical signal power and propagation loss in the access network.

[0004] In optical intensity monitoring in WMD transmission, a technique is used in which the intensity of optical signals from a plurality of optical fibers is simultaneously monitored by combining optical fibers arranged one-dimensionally with an optical sensor (see, for example, Patent Document 2).

[0005] However, conventional light intensity monitoring using an arrangement configuration still has the following problems.

[0006] As optical communications become more widespread and the number of fiber cores in optical equipment / cables increases, firstly, when an optical coupler is used for each optical fiber core as in Patent Document 1, the cost and size increase in proportion to the number of cores. Even when optical sensors are arranged in a one-dimensional array in accordance with the number of optical fiber cores as in Patent Document 2, there is a limit to the array arrangement of optical fibers and optical sensors, and if the number of optical fiber cores increases beyond that, the cost and size increase in proportion to the number of cores.

[0007] Another possible way to achieve this type of light intensity monitoring is to use Fresnel reflection in spatial optical systems. However, Fresnel reflection has different reflectance depending on whether the incident p-polarized or s-polarized light is polarized. As an example of the difference in reflectance between p-polarized and s-polarized light, Figure 1 shows an example of calculating the incident angle and reflectance of p-polarized and s-polarized light entering air from quartz glass. As shown in Figure 1, if the polarization state of the incident light fluctuates, the branching ratio of the light branched to the optical sensor side will fluctuate. For this reason, using Fresnel reflection poses the problem of inaccurate measurements. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent No. 3450104 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-219523 Summary of the Invention [Problem to be solved by the invention]

[0009] The present disclosure has been made in consideration of these points, and aims to realize an optical intensity measurement method that can measure the optical intensity of an optical signal regardless of the polarization state of the incident optical signal, even in an optical fiber with a large number of cores, such as several tens of cores. [Means for solving the problem]

[0010] In order to achieve the above object, the light intensity measurement method of the present disclosure includes: An optical monitor device for detecting the intensity of light propagating through a plurality of optical fibers, The optical monitor device of the present disclosure is used.

[0011] The optical monitoring device of the present disclosure comprises: a plurality of branching units that branch the incident light from the plurality of optical fibers that has entered a predetermined incident region into different directions; a plurality of optical sensors that receive the branched light beams branched by the plurality of branching units, respectively; Equipped with the plurality of optical sensors are two-dimensionally arranged with pixels whose number is greater than the number of the plurality of optical fibers, and detect light intensity for each pixel corresponding to an incident position in the incident region; The light intensities detected by the plurality of optical sensors are summed for each pixel corresponding to the incident position in the incident area.

[0012] In the present disclosure, multiple optical sensors are provided, the optical intensity of each branched light is detected for each pixel corresponding to the incident position in the incident region, and the sum of the optical intensities for each pixel is calculated. This allows the present disclosure to measure the optical intensity of incident light for each optical fiber, even for optical fibers with a large number of cores, such as several tens of cores. Here, the polarization axis is expressed in two directions: a certain y-direction and a z-direction perpendicular to the x-axis, assuming that the direction of light travels is the x-axis. Therefore, the present disclosure provides two branching sections, reflects light in different directions at the multiple branching sections, and considers the proportion of p-polarized and s-polarized light reflected in each direction, thereby enabling the optical intensity of an optical signal to be measured regardless of the polarization state of the incident optical signal.

[0013] The optical monitoring device of the present disclosure comprises: a first branching unit that branches incident light incident from a predetermined incident region into two directions, a first direction and a second direction; a first optical sensor that receives the branched light branched in the second direction by the first branching unit and detects the intensity of the light branched by the first branching unit for each incident position in the incident area; a second branching unit that branches the branched light beam branched in the first direction by the first branching unit into two beams, one in a third direction and the other in the first direction; a second optical sensor that receives the branched light branched in the third direction by the second branching unit and detects the intensity of the light branched by the second branching unit for each incident position in the incident area; The device may also include:

[0014] The optical monitoring device an optical component having the plurality of branching portions; a plurality of incident-side optical fibers arranged in a two-dimensional array so as to make light incident on the incident region of the optical component; a plurality of output-side optical fibers arranged in a two-dimensional array so as to receive each of the output beams from the optical component; an incident-side optical lens disposed between the optical component and the incident-side optical fiber, and converting each light beam incident on the optical component into a parallel beam; an output optical lens disposed between the optical component and the output optical fiber, for coupling each output light from the optical component to the output optical fiber; The device may also include:

[0015] The optical component is a first member having a uniform refractive index; a first monolayer film in contact with the first member and having a uniform refractive index different from that of the first member; a second member in contact with the first monolayer film and having the same refractive index as the first member; a second single-layer film in contact with the second member and having a uniform refractive index different from the refractive indexes of the first member and the second member; The optical element may further include a third member connected to the second single-layer film and the output-side optical lens and having the same refractive index as the first member. In this embodiment, the first monolayer film functions as the first branch portion, the second monolayer film functions as the second branch portion, a first refractive index interface between the first member and the first monolayer film and a second refractive index interface between the second member and the first monolayer film have a specific first incident angle with respect to the incident light, a third refractive index interface between the second member and the second monolayer film and a fourth refractive index interface between the third member and the second monolayer film have a specific second incident angle with respect to the incident light, the first direction is a direction transmitted from the first refractive index interface through the fourth refractive index interface, the second direction is a direction reflected at the first refractive index interface, The third direction may be a direction reflected at the third refractive index interface.

[0016] The optical monitoring device a first optical sensor that receives branched light from the first monolayer film; a second optical sensor that receives branched light from the second monolayer film; Equipped with The optical intensity I of the f-th optical fiber in the plurality of optical fibers is expressed by the following equations (16) and (17). Rf and the average pixel output of the first optical sensor and the second optical sensor, the optical intensity I of the f-th optical fiber in the plurality of optical fibers is calculated. Rf may be calculated.

[0017] Here, the angle between the incident surface of the first single-layer film and the incident surface of the second single-layer film may be 90 degrees, and the extraction rates of p-polarized light and s-polarized light in the first single-layer film and the second single-layer film may be equal. In this case, R, which is defined using the extraction rates of p-polarized light and s-polarized light in the first single-layer film and the second single-layer film, may be defined by equation (6) below, and average pixel outputs of the first photosensor and the second photosensor may be calculated based on equation (7) below.

[0018] Here, the angle formed by the incident surface of the first single-layer film and the incident surface of the second single-layer film may be 90 degrees. In this case, R, which is defined using the extraction rates of p-polarized light and s-polarized light in the first single-layer film and the second single-layer film, may be defined by equation (43) described later, and average pixel outputs of the first optical sensor and the second optical sensor may be calculated based on equation (31) described later.

[0019] Here, R defined by R, which is defined using the extraction rates of p-polarized light and s-polarized light in the first single-layer film and the second single-layer film, and the angle between the incident surface of the first single-layer film and the incident surface of the second single-layer film, may be defined by equation (53) described later, and the average pixel output of the first optical sensor and the second optical sensor may be calculated based on equation (32) described later.

[0020] A light intensity measurement method according to the present disclosure is a light intensity measurement method using an optical monitor device according to the present disclosure, measuring output values ​​of light intensity detected by each pixel of the plurality of optical sensors when light is emitted from each of the plurality of optical fibers, thereby obtaining a correspondence relationship between the plurality of optical fibers and each of the optical sensors in advance; a light intensity measurement method for detecting light intensities of pixels included in the plurality of optical sensors while light is propagating through the plurality of optical fibers, and measuring the light intensities of the propagating light through the plurality of optical fibers for each optical fiber based on the correspondence relationship; When acquiring the correspondence relationship, a sum of output values ​​of the plurality of optical sensors is calculated for each pixel corresponding to an incident position in the incident area. It has the following characteristics.

[0021] In acquiring the correspondence relationship, measurements may be performed multiple times, the average value of the output values ​​of each optical sensor is calculated for each pixel, and the sum of the average values ​​may be used.

[0022] The above disclosures can be combined as much as possible. [Effects of the Invention]

[0023] According to the present disclosure, even in the case of an optical fiber with a large number of cores, such as several tens of cores, the intensity of the optical signal can be accurately measured regardless of the polarization state of the incident optical signal. [Brief explanation of the drawings]

[0024] [Figure 1] 10 is a diagram illustrating the relationship between the incident angle and reflectance of s-polarized light and p-polarized light. FIG. [Figure 2] 1 is a diagram illustrating an optical monitor device according to the present disclosure. [Figure 3] 1 is a diagram illustrating an optical monitor device according to the present disclosure. [Figure 4] 1 is a diagram illustrating an optical monitor device according to the present disclosure. [Figure 5] 1 is a diagram illustrating an optical monitor device according to the present disclosure. [Figure 6] 1 is a diagram illustrating an optical monitor device according to the present disclosure. [Figure 7] 3 is a diagram illustrating the angle θ formed between the incident surface of the first single-layer film and the incident surface of the second single-layer film. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0025] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the embodiments shown below. These implementation examples are merely illustrative, and the present disclosure can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art. Note that components with the same reference numerals in this specification and drawings indicate the same components.

[0026] (First embodiment) In order to solve the above problem, the present disclosure provides a light intensity measurement method using an optical monitor device that can be realized by the configuration exemplified in FIG. The present disclosure provides an optical monitoring device for detecting the intensity of light propagating through a plurality of incident-side optical fibers 11, a spatial optical system (30) that is an optical component having a plurality of branching units that branch the incident light from the plurality of optical fibers (11) that has entered a predetermined incident region into different directions; a plurality of optical sensors 5A and 5B that receive the branched light beams branched by the plurality of branching units, respectively; Equipped with.

[0027] Specifically, the optical monitor device used in the present disclosure is a spatial optical system (30) that splits and emits a part of incident light (41) in a specific direction (second direction), a remaining part in another specific direction (third direction), and a majority of the remaining part in yet another specific direction (first direction) at a specific splitting ratio; an incident-side optical fiber 11 that propagates a plurality of light beams arranged in a two-dimensional array so as to input the light beams into the spatial optical system 30; a plurality of light-propagating output optical fibers (12) arranged to receive most of the output light (42) from the spatial optical system (30) in a first direction; a first optical sensor 5A disposed to receive a first portion of emitted light 43A from the spatial optical system 30 in the second direction; a second optical sensor 5B disposed to receive a second portion of the emitted light 43B from the spatial optical system 30 in a third direction; an incident-side optical lens 21 disposed between the spatial optical system 30 and the incident-side optical fiber 11, for converting incident light into an incident region of the spatial optical system 30 into parallel light; an output-side optical lens 22 that is disposed between the spatial optical system 30 and the output-side optical fiber 12 and efficiently couples the output light from the spatial optical system 30 to the output-side optical fiber 12; It has.

[0028] The optical sensors 5A and 5B have a two-dimensional array of pixels, the number of which is greater than the number of the optical fibers 11, and detect the light intensity for each pixel corresponding to the incident position in the incident region. In this embodiment, a calculation device (not shown) calculates the sum of the light intensities detected by the optical sensors 5A and 5B for each pixel corresponding to the incident position in the incident region, and calculates the intensity of light propagating through at least one of the optical fibers 11 using the calculated sum of the light intensities of each pixel.

[0029] As shown in FIG. 2, the spatial optical system 30 includes: a first member 30A connected to the incident-side optical lens 21 and having a uniform refractive index; a first single layer film 33A in contact with the first member 30A and having a uniform refractive index different from that of the first member 30A; a second member 30B in contact with the first single-layer film 33A and having the same refractive index as the first member 30A; a second monolayer film 33B in contact with the second member 30B and having the same refractive index as the first monolayer film 33A; a third member 30C connected to the second single-layer film 33B and the output-side optical lens 22 and having the same refractive index as the first member 30A; It may be configured as follows.

[0030] The surface of the first member 30A connected to the incident-side optical lens 21 includes an incident region. In the present disclosure, by having such a refractive index in the spatial optical system 30, the relative positions of the parallel light beams incident on the first member 30A from the incident region can be maintained as they are in the incident region. Here, the refractive index of the first single-layer film 33A and the refractive index of the second single-layer film 33B are arbitrary. For example, the refractive index of the first single-layer film 33A and the refractive index of the second single-layer film 33B are lower or higher than the refractive indexes of the first member 30A, the second member 30B, and the third member 30C.

[0031] In this embodiment, an example is shown in which the angle θ between the incident surface of the first single-layer film 33A and the incident surface of the second single-layer film 33B is 90 degrees. The first single-layer film 33A functions as a first branching section that branches the incident light into two, that is, in a first direction and a second direction. The second single-layer film 33B functions as a second branching section that branches the branched light, which has been branched in the first direction by the first single-layer film 33A, into two, that is, in a third direction perpendicular to both the first direction and the second direction, and in the first direction.

[0032] To facilitate understanding of the spatial optical system 30 shown in Fig. 2, Fig. 3 shows only one of the two-dimensionally arranged incident-side optical fibers 11 and output-side optical fibers 12. In the following description, the light transmitted through the first single-layer film 33A in the x-axis direction is referred to as the majority of output light 42A, and the light transmitted through the second single-layer film 33B in the x-axis direction is referred to as the majority of output light 42B. It is also assumed that the optical axis of the incident light 41 is in the x-axis direction.

[0033] In Figure 3, the boundary surface between the first member 30A and the first single-layer film 33A is referred to as the first refractive index interface 31A, the boundary surface between the second member 30B and the first single-layer film 33A is referred to as the second refractive index interface 31B, the boundary surface between the second member 30B and the second single-layer film 33B is referred to as the third refractive index interface 31C, and the boundary surface between the third member 30C and the second single-layer film 33B is referred to as the fourth refractive index interface 31D.

[0034] FIG. 2 shows an example in which the first direction is the x-axis direction, the second direction is the z-axis direction, and the third direction is the y-axis direction, but these directions can be any directions depending on the optical design of the spatial optical system 30.

[0035] The spatial optical system 30 includes: a first refractive index interface 31A and a second refractive index interface 31B that are parallel to each other and have a specific first incident angle with respect to the incident light 41; a third refractive index interface (31C) and a fourth refractive index interface (31D) that are parallel to each other and are arranged closer to the output-side optical fiber (12) than the first refractive index interface (31A) and the second refractive index interface (31B), have the specific second incident angle with the incident light (41), and have an incident plane orthogonal to the incident planes of the first refractive index interface (31A) and the second refractive index interface (31B); The first direction in which most of the emitted light 42 is emitted is the direction in which the light passes through the first to fourth refractive index interfaces (31A, 31B, 31C, 31D), The first incident angle and the second incident angle are equal, the second direction in which the first part of the emitted light 43A is emitted is the direction in which the light is reflected at the first refractive index interface 31A; The third direction in which the second part of the emitted light 43B is emitted is the direction in which it is reflected at the third refractive index interface 31C.

[0036] The third refractive index interface 31C and the fourth refractive index interface 31D may be surfaces obtained by rotating the first refractive index interface 31A and the second refractive index interface 31B by 90 degrees in the circumferential direction around the optical axis of the incident light 41.

[0037] In FIG. 3, the first direction (x direction) is the direction in which incident light 41 incident on first monolayer film 33A travels straight, and is also the direction in which most of emitted light 42A travels. The second direction (z direction) is the direction in which a first portion of emitted light 43A reflected by first monolayer film 33A travels. The third direction (y direction) is the direction in which a second portion of emitted light 43B reflected by second monolayer film 33B travels. As described above, by arranging first monolayer film 33A and second monolayer film 33B so that the plane containing the first and second directions (xz plane) and the plane containing the first and third directions (xy plane) are perpendicular to each other, the incident plane of first monolayer film 33A and the incident plane of second monolayer film 33B can be made perpendicular to each other.

[0038] 2 and 3, as described above, the plane of incidence of the first single-layer film 33A and the plane of incidence of the second single-layer film 33B are perpendicular to each other, so that p-polarized light in the first single-layer film 33A becomes s-polarized light in the second single-layer film 33B, and s-polarized light in the first single-layer film 33A becomes p-polarized light in the second single-layer film 33B. The first single-layer film 33A and the second single-layer film 33B have the same refractive index and film thickness, so that the extraction rate of p-polarized light in the first single-layer film 33A is equal to that of the second single-layer film 33B, and the extraction rate of s-polarized light in the first single-layer film 33A is equal to that of the second single-layer film 33B.

[0039] A method for measuring light intensity using this optical monitor device will be described with reference to FIGS. As shown in Figure 3, the intensity of p-polarized and s-polarized incident light is expressed as E P and E S Then, the polarization state of the incident light is expressed by the following equation:

number

[0040] The extraction rates of p-polarized light and s-polarized light in the first single-layer film 33A and the second single-layer film 33B are R P and R S Then, the polarization state of the light transmitted through the first single-layer film 33A is expressed as follows:

number

[0041] The intensities of light incident on the optical sensors 5A and 5B are expressed by equations (3) and (4), respectively.

number

[0042] At this time, the light intensity to be measured is expressed by the following equation:

number

[0043] When R expressed by equation (6) is defined, equation (7) holds. (Number 6) R p +R s -R p R s =R (6) (Number 7) I A +I B =RI (7)

[0044] First, only the fth optical fiber has a light intensity I Rf Measurement is repeated J times with the incident light being incident. During this measurement, the polarization state of the incident light does not need to be constant, and may vary for each measurement. In this jth measurement, the ratio of the light intensity split into the first monolayer film 33A to the light intensity split into the first monolayer film 33A and the second monolayer film 33B is defined as α j Then, as shown in FIG. 4, the intensity of light incident on the optical sensors 5A and 5B is expressed by the following equation:

number

[0045] The light intensity S detected at the ith pixel i of the optical sensors 5A and 5B at the jth time Afij and S Bfij is expressed by equations (10) and (11).

number

[0046] The average value (average pixel output) of the output values ​​of the light intensity detected at pixel i of the optical sensors 5A and 5B in the J measurements is given by equations (12) and (13).

number

[0047] The sum of the average pixel outputs of the optical sensors 5A and 5B for all pixels is given by equations (14) and (15).

number

[0048] From the above, the optical intensity I of the fth optical fiber is Rf The following equation can be obtained, which is the correspondence relationship between the average pixel outputs of the optical sensors 5A and 5B.

number

[0049] Therefore, as a preliminary measurement, the calculation device measures the light intensity I from only one optical fiber in the order of optical fibers 1, 2, ..., f, ... Rf In the state where light of the order of magnitude of the incident light is incident, the equations (18) and (19) are calculated for each pixel i of the optical sensors 5A and 5B, and a matrix A having the calculated values ​​as its elements is obtained. Rfi ,B Rfi Create it in advance.

number

number

number

number

[0050] Next, light beams with different intensities are incident simultaneously from the optical fibers 1 to f, and the optical sensors 5A and 5B measure the intensities of these beams. The intensities of the beams incident on the optical fibers 1 to f are expressed as I1 to I f ..., and the ratio of the average intensity of the extracted light directed to the optical sensor 5A and the optical sensor 5B during measurement is expressed as equation (20).

number

[0051] FIG. 6 shows the matrix A of the optical sensor 5A. Rfi and A i An example of the correspondence relationship is shown below. From the linearity of light, the output value A of the light intensity detected by the optical sensor 5A is i can be expressed as follows:

number

number

[0052] Similarly, the optical sensor 5B has the formula (23).

number

[0053] As described above, the calculation device of the present disclosure calculates the light intensities I1 to I f ... is the output value A of pixel i of the optical sensors 5A and 5B i ,B i and the matrix A created in advance Rfi ,B Rfi This can be calculated using equation (24) and obtained as the measurement result.

number

[0054] As mentioned above, the matrix A that was created in advance Rfi ,B Rfi can be created from only the output values ​​of each pixel of the optical sensors 5A and 5B in a previous measurement and the determined light intensity value, and can be created for any polarization state (α). Also, in the measurement, the matrix A Rfi ,B Rfi Using the light intensities I1 to I f ... can be measured because equation (7) holds true in Figure 3.

[0055] If the S / N ratio of the optical sensors 5A and 5B is sufficiently good and repeated measurements are not necessary, one measurement may be performed instead of J measurements. In this case, the average value obtained by the repeated measurements is

number

[0056] In this embodiment, an example has been shown in which R is defined using the extraction rates of p-polarized light and s-polarized light in the first single-layer film 33A and the second single-layer film 33B as shown in equation (6), but R in the present disclosure may also take into account the angle θ between the incident surface of the first single-layer film 33A and the incident surface of the second single-layer film 33B.

[0057] (Second embodiment) When the refractive index or film thickness of the first single-layer film 33A and the second single-layer film 33B are different, or when the angle of incidence of the incident light is different, the extraction rates of p-polarized light and s-polarized light may differ. In this case, the extraction rates of p-polarized light and s-polarized light of the first single-layer film 33A are expressed as R P ,R S , the extraction rates of p-polarized light and s-polarized light of the second monolayer film 33B are R P ',R S ', the following equation holds:

number

[0058] Only p-polarized light and s-polarized light are incident on each of the branching portions of the first single-layer film 33A and the second single-layer film 33B using a polarization controller. P ,R S , R P ',R S ' is measured, and based on the results, the average value of the output values ​​of each pixel of the optical sensor 5B (average pixel output) is calculated. (R p -R s ) / {R P '(1-R s )-R S '(1-R p )} By using the doubled value, it is possible to use the same light intensity measurement method as in the first embodiment.

[0059] (Third embodiment) Furthermore, in the present disclosure, the angle between the incident surface of the first single-layer film 33A and the incident surface of the second single-layer film 33B may not be 90 degrees, but may be any angle θ other than 0 degrees and 180 degrees, as shown in Figure 7. In this case, the following equation holds:

number

[0060] R in advance P ,R S , R P ',R S ', θ are measured, and based on the results, the average value of the output values ​​of each pixel of the optical sensor 5B (average pixel output) is calculated.

number

[0061] The above are exemplary embodiments, but the present invention is not limited to these. For example, the spatial optical system 30 is not limited to a cubic shape, and may be any shape, such as a rectangular parallelepiped. Furthermore, the optical sensors 5A and 5B may be disposed at any position where they can receive the light branched by the spatial optical system 30. For example, the optical sensors 5A and 5B may be embedded inside the spatial optical system 30.

[0062] The optical monitoring device of the present disclosure can also be used to monitor any light transmitted in an optical transmission system. For example, the optical monitoring device of the present disclosure can be installed in any device used in an optical transmission system, such as a transmitter, receiver, or repeater, and the measurement results from the optical sensors 5A and 5B can be used for feedback or feedforward to any component inside or outside the device. Furthermore, the optical monitoring device of the present disclosure can be inserted midway through a transmission line in an optical transmission system to measure the intensity and propagation loss of an optical signal in the transmission line.

[0063] (Definition of R in the second embodiment) When the extraction rates of p-polarized light and s-polarized light in the first single-layer film 33A and the second single-layer film 33B are different, the intensity of light incident on the optical sensor 5B is expressed by the following equation.

number

[0064] The propagating light intensity I at the time of incidence is expressed by the following equation:

number

[0065] Therefore, we use R defined below.

number

[0066] As a result, the following relationship is obtained using equation (42) for the propagating light intensity I at the time of incidence:

number

[0067] (Definition of R in the third embodiment) When the angle θ between the incident surface of the first monolayer film 33A and the incident surface of the second monolayer film 33B is not 90 degrees but is an arbitrary angle θ as shown in FIG. 7, the intensity of light incident on the optical sensor 5B is expressed by the following equation:

number

[0068] The propagating light intensity I at the time of incidence is expressed by the following equation:

number

[0069] Therefore, in this embodiment, R defined below is used.

number

[0070] As a result, the following relationship is obtained using equation (52) for the propagating light intensity I at the time of incidence:

number

[0071] The present disclosure can be applied to the information and communications industry. [Explanation of symbols]

[0072] 5A, 5B: Optical sensor 11: Input optical fiber 12: Output optical fiber 13: Incident side ferrule 14: Output ferrule 15: Guide pin 21: Input optical lens 22: Output optical lens 31: Refractive index interface 33A, 33B: Single layer membrane 34: Spacer 41: Incident light 42: Most of the emitted light 43A, 43B: Part of the emitted light 30: Spatial optical system 30A, 30B, 30C: Components

Claims

1. An optical monitor device for detecting the intensity of light propagating through a plurality of optical fibers, a plurality of branching units that branch the incident light from the plurality of optical fibers that has entered a predetermined incident region into different directions; a plurality of optical sensors that receive the branched light beams branched by the plurality of branching units, respectively; Equipped with a first branching portion of the plurality of branching portions branches incident light from the plurality of optical fibers into a specific first direction and a second direction different from the first direction; a second branching unit among the plurality of branching units branches the branched light branched in the first direction into a third direction perpendicular to both the first direction and the second direction; a first optical sensor among the plurality of optical sensors receives branched light branched in the second direction; a second optical sensor among the plurality of optical sensors receives branched light branched in the third direction; the first optical sensor and the second optical sensor have a number of pixels two-dimensionally arranged that is greater than the number of the plurality of optical fibers, and detect light intensity for each pixel corresponding to an incident position in the incident region; calculating a sum of the light intensities detected by the first optical sensor and the second optical sensor for each pixel corresponding to an incident position in the incident region, and using the calculated sum of the light intensities of each pixel to calculate the intensity of light propagating through at least one of the plurality of optical fibers; Optical monitor device.

2. a first member having a uniform refractive index; a first monolayer film in contact with the first member and having a uniform refractive index different from that of the first member; a second member in contact with the first monolayer film and having the same refractive index as the first member; a second single-layer film in contact with the second member and having a uniform refractive index different from the refractive indexes of the first member and the second member; a third member in contact with the second monolayer film and having the same refractive index as the first member; an optical component comprising: a first refractive index interface between the first member and the first single-layer film and a second refractive index interface between the second member and the first single-layer film have a first incident angle with respect to the incident light, a third refractive index interface between the second member and the second single-layer film and a fourth refractive index interface between the third member and the second single-layer film have a second incident angle with the incident light, the first monolayer film and the second monolayer film function as the plurality of branch portions; 10. The optical monitor device of claim 1.

3. The optical intensity I of the fth optical fiber in the plurality of optical fibers is expressed by the following formula: Ｒｆ and the average pixel output of the first optical sensor and the second optical sensor, the light intensity I of the f-th optical fiber in the plurality of optical fibers is calculated. Ｒｆ Calculate 3. The optical monitor device according to claim 2. [Math C11] Also, k Ａｆｉ is the ratio of the light intensity incident on the i-th pixel i to the light from the optical fiber f incident on the first optical sensor, k Ｂｆｉ is the ratio of the light intensity incident on the ith pixel i to the light from the optical fiber f incident on the second optical sensor, K is the sensor sensitivity of the first optical sensor and the second optical sensor, R is a value defined using the extraction rates of p-polarized light and s-polarized light in the first single-layer film and the second single-layer film, and the angle between the incident plane of the first single-layer film and the incident plane of the second single-layer film.

4. wherein R is defined in formula C21; 4. The optical monitor device of claim 3, wherein the average pixel output of the first optical sensor and the second optical sensor is calculated based on equation C22. [Number C21] [Number C22] where: I Ａ and I Ｂ is the light intensity detected by the first light sensor and the second light sensor, R Ｐ and R Ｓ is the extraction ratio of p-polarized light and s-polarized light in the first monolayer film, R Ｐ ' and R Ｓ ' is the extraction ratio of p-polarized light and s-polarized light in the second monolayer film.

5. an angle formed between an incident surface of the first single-layer film and an incident surface of the second single-layer film is 90 degrees; wherein R is defined by formula C31; 4. The optical monitor device of claim 3, wherein the average pixel output of the first optical sensor and the second optical sensor is calculated based on equation C32. [Number C31] [Number C32] where: I Ａ and I Ｂ is the light intensity detected by the first light sensor and the second light sensor, R Ｐ and R Ｓ is the extraction ratio of p-polarized light and s-polarized light in the first monolayer film, R Ｐ ' and R Ｓ ' is the extraction ratio of p-polarized light and s-polarized light in the second monolayer film.

6. an angle formed between an incident surface of the first single-layer film and an incident surface of the second single-layer film is 90 degrees; the extraction rates of p-polarized light and s-polarized light in the first single-layer film and the second single-layer film are equal; wherein R is defined as formula C41; 4. The optical monitor device of claim 3, wherein the average pixel output of the first optical sensor and the second optical sensor is calculated based on equation C42. R ｐ +R ｓ -R ｐ R ｓ =R (C41) I Ａ +I Ｂ =RI (C42) Here, I Ａ and I Ｂ is the light intensity detected by the first light sensor and the second light sensor, R Ｐ and R Ｓ denotes the extraction rates of p-polarized light and s-polarized light in the first single-layer film and the second single-layer film.

7. A method for measuring optical intensity using the optical monitor device according to any one of claims 1 to 6, comprising: measuring an output value of light intensity detected by each pixel of the plurality of optical sensors when light is emitted from each of the plurality of optical fibers, thereby obtaining in advance a correspondence relationship between each of the plurality of optical fibers and each pixel of the plurality of optical sensors; detecting the light intensity of each pixel of the plurality of optical sensors while the plurality of optical fibers are propagating light, and measuring the light intensity of the propagating light of the plurality of optical fibers for each optical fiber based on the correspondence relationship; A light intensity measuring method, characterized in that, in acquiring the correspondence relationship, a sum of output values ​​of the plurality of optical sensors is calculated for each pixel corresponding to an incident position in the incident area.

8. 8. The light intensity measurement method according to claim 7, wherein, in acquiring the correspondence relationship, measurements are performed a plurality of times, an average value of the output values ​​of each optical sensor is calculated for each pixel, and the sum of the average values ​​is used.

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