Information processing device, information processing method, and program

Abstract

The present invention achieves low-cost determination of whether or not characteristics of an optical fiber are within an allowable range.　In the present invention, a determination information calculation unit calculates determination information for determining whether or not characteristics of an optical fiber are within an allowable range on the basis of a far field pattern (FFP) of light output from the optical fiber. For example, the determination information calculation unit calculates the determination information on the basis of the result of applying an affine transformation to the FFP. The coupling efficiency obtained when the optical fiber is used on the transmission side of an optical coupling system satisfies a reference value if the characteristics of the optical fiber are within the allowable range.

Description

Information Processing Apparatus, Information Processing Method, and Program

[0001] The present technology relates to an information processing apparatus, an information processing method, and a program, and more particularly to an information processing apparatus and the like used for determining whether the characteristics of an optical fiber are within an allowable range.

[0002] In optical communication (see, for example, Patent Document 1), the coupling efficiency (hereinafter simply referred to as "coupling efficiency") of light between the transmission side (Tx side) and the reception side (Rx side) can vary according to the characteristics of the optical fiber on the transmission side. Therefore, when there is a large variation in the characteristics of the optical fiber, it is necessary to select an optical fiber whose characteristics are within the allowable range in order to achieve a coupling efficiency equal to or higher than a reference value. Parameters representing the characteristics of the optical fiber include core radius, α, central dip, and the like. However, high-precision measurement of these parameters requires expensive equipment, and the correlation between these parameters and the coupling efficiency is not clear.

[0003] International Publication No. 2017 / 056889

[0004] An object of the present technology is to realize determination of whether the characteristics of an optical fiber are within an allowable range at low cost.

[0005] The concept of the present technology resides in an information processing apparatus including a reception unit that receives a far-field pattern (FFP) of light output from an optical fiber, and a determination information calculation unit that calculates determination information for determining whether the characteristics of the optical fiber are within an allowable range based on the FFP.

[0006] Another concept of the present technology resides in an information processing method having a procedure for receiving a far-field pattern (FFP) of light output from an optical fiber, and a procedure for calculating determination information for determining whether the characteristics of the optical fiber are within an allowable range based on the FFP.

[0007] Another concept of this technology is a program that causes a computer to function as a determination information calculation means, which calculates determination information to determine whether the characteristics of the optical fiber are within an acceptable range based on the far-field pattern (FFP) of the light output from the optical fiber.

[0008] Exemplary embodiments of this technology will be described based on the following drawings. Figure 1 is a diagram illustrating the spatial coupling of light. Figure 2 is a graph showing the relationship between the normalized frequency V and the normalized propagation constant b. Figure 3 is a diagram showing an example of a transmit / receive structure. Figure 4 shows an example of the refractive index distribution of an optical fiber. Figure 5 is a diagram showing the simulation results of the coupling efficiency. Figure 6A shows the intensity distribution of light having only the fundamental mode component, and Figure 6B shows the intensity distribution of light having both the fundamental mode and the first mode components. Figure 6C is a diagram illustrating the direction of propagation of light output from an optical fiber. Figure 7A is a graph showing the near-field pattern according to the position of the output end, and Figure 7B is a diagram showing the position of the output end. Figures 8A to 8D are graphs showing the intensity distribution when the mode ratios are 20:80, 40:60, 60:40, and 80:20, respectively. Figure 9A is a graph showing the far-field pattern, and Figure 9B is a diagram illustrating the far-field pattern. Figure 10 is a graph showing the result of applying the first variable transformation to the far-field pattern. Figure 11 is a graph showing the result of applying the second variable transformation to the far-field pattern. Figure 12A is a graph showing the far-field pattern according to the position of the output terminal, and Figure 12B is a graph showing the result of applying the first and second variable transformations to that far-field pattern. Figure 13 is a graph to explain the correlation between far-field pattern features and worst-case coupling efficiency. Figure 14 is a graph with an increased number of samples to explain the correlation between far-field pattern features and worst-case coupling efficiency. Figure 15A is a diagram showing the transmit / receive structure assumed in the simulation for determining the worst-case coupling efficiency, and Figure 15B is a diagram to explain the worst case. Figure 16 is a diagram to explain the normalized far-field pattern features. Figure 17 is a diagram showing an example configuration of a determination system that determines whether the characteristics of an optical fiber are within an acceptable range. Figure 18A is a diagram schematically showing the fitting of an optical fiber to the far-field pattern measurement section, and Figure 18B is a diagram to explain an example of a method for measuring the far-field pattern. Figure 19 is a diagram showing an example of the processing procedure on the light source side and the determination device side in the determination system.Figure 20 is a block diagram showing an example of a computer hardware configuration.

[0009] The following describes embodiments for carrying out the invention. The description will be in the following order: 1. Optical communication 2. Judgment principle 3. Judgment system 4. Processing procedure 5. Example of computer hardware configuration 6. Modified examples

[0010] "1. Optical Communication" Figure 1 is a diagram illustrating spatial light coupling. In this example, at the transmitting side, light is output from the optical fiber 10T, and this light is transformed into collimated light by the lens 11T. Symmetrically with the transmitting side, at the receiving side, this collimated light is focused by the lens 11R, and this focused light (convergent light) is input to the optical fiber 10R. The optical fibers 10T and 10R have a core 10a in the center which forms the optical path, and a cladding 10b that surrounds it. Since the refractive index n1 of the core 10a is high and the refractive index n2 of the cladding 10b is low, the light is confined to the core 10a. In such optical communication, the coupling efficiency varies depending on the characteristics of the optical fiber 10T on the transmitting side.

[0011] When a single-mode optical fiber, designed to propagate light of a first wavelength, is input with light of a second wavelength different from the first, first-order mode light may be generated in addition to the fundamental mode light within the optical fiber. In double-mode optical communication, which utilizes this principle, power loss can be reduced because the first-order mode component, generated by optical axis misalignment, propagates along with the fundamental mode component within the optical fiber.

[0012] Figure 2 is a graph showing the relationship between the normalized frequency V and the normalized propagation constant b. Here, the optical fiber is a step-index optical fiber. The normalized propagation constant b on the vertical axis is defined for each mode and indicates how much light of that mode propagates. b=0 indicates full cutoff, and b=1 indicates full propagation. The normalized frequency V on the horizontal axis can be expressed by the following formula (1): where d is the core diameter, NA is the numerical aperture, and λ is the wavelength of light. V = πdNA / λ ... (1)

[0013] When V < 2.405, LP 01 Other modes are blocked (single mode). LP 01 This is the fundamental mode, also called the zeroth-order mode. In single-mode optical communication, when λ = 1310 nm, d = 8 μm, and NA = 0.1, V = 1.92 < 2.405 is obtained from equation (1). Here, 1310 nm is an example of the first wavelength.

[0014] On the other hand, when λ = 850 nm, V = 2.96 > 2.405. Therefore, LP 01 The basic mode and LP 11 The first mode can propagate (double mode). Here, 850 nm is an example of a second wavelength.

[0015] Figure 3 shows an example of a transmission / reception structure for double-mode optical communication. The transmitting side has a connector body 101. This connector body 101 is made of a light-transmitting material such as synthetic resin or glass. A lens (collimator) 102 and an optical fiber insertion hole 103 are integrally formed on the connector body 101. Lens 102 corresponds to lens 11T in Figure 1. An optical fiber 104, corresponding to optical fiber 10T in Figure 1, is inserted into the optical fiber insertion hole 103. A gradient-index lens is provided at the output end of the optical fiber 104. The gradient-index lens 105 is a cylindrical lens. The refractive index of the gradient-index lens 105 is equivalent to, for example, the refractive index of the core of the optical fiber 104 on the optical axis, and decreases as it moves away from the optical axis.

[0016] Since the structure of the receiving side is the same as (symmetrical) as that of the transmitting side, a detailed explanation will be omitted. The refractive index distribution lens 205 provided at the input end of the optical fiber 204 on the receiving side can return light that has shifted from the optical axis towards the center, thereby reducing coupling loss due to optical axis misalignment.

[0017] Furthermore, if a distributed refractive index lens 205 is provided on the receiving side, aberration can be suppressed more effectively by providing a similar lens (distributed refractive index lens 105) on the transmitting side as well. Therefore, in this example, a distributed refractive index lens (105) is also provided on the transmitting side.

[0018] The optical fiber 104 is, for example, a graded-index optical fiber and has the refractive index distribution shown in Figure 4. The characteristics of the optical fiber 104 can be expressed by three parameters, for example: the core diameter which indicates the width of the refractive index distribution, α which indicates the shape (steepness) of the refractive index distribution, and the central dip which indicates the depth of the central depression. Due to manufacturing process constraints, it is difficult to make the central dip zero.

[0019] Figure 5 shows the simulation results of the coupling efficiency when four parameters—the three parameters of the transmitting optical fiber 104 mentioned above, and the ratio of the fundamental mode and first mode of light propagating through this optical fiber 104—are randomly selected 120 times in the transmitting / receiving structure of Figure 3. If the baseline value for coupling efficiency is set to, for example, 0.6, it can be seen that the results include trials (experiments) that do not meet the baseline value. In cases where there is such a large variation in the characteristics of optical fibers, it is necessary to select optical fibers with characteristics within an acceptable range in order to achieve a coupling efficiency above the baseline value. Note that the coupling efficiency here refers to the worst-case coupling efficiency η, which will be discussed later. Ｗ That is the case.

[0020] "2. Determination Principle" This section explains the determination principle for determining whether the characteristics of the optical fiber are within the acceptable range in this technology. This method enables highly accurate determination without requiring expensive equipment such as an optical fiber refractive index meter, even when determination based on three parameters is difficult.

[0021] Figure 6A shows the intensity distribution of light containing only the fundamental mode components in a cross-section along the axial direction of an optical fiber. It can be seen that the intensity is high on the core side (center side) of the optical fiber and low on the cladding side (outside side). The graph on the right shows the near-field pattern (NFP). Here, the NFP is the intensity distribution at the output end of the optical fiber, depending on the position x from the center in the radial direction of the optical fiber.

[0022] Figure 6B shows the intensity distribution of light with fundamental mode and first-order mode components in a cross-section along the axial direction of an optical fiber. The ratio of fundamental mode to first-order mode is 50:50. It can be seen that high-intensity spots appear alternately above and below the core. The graph on the right shows NFP. When the high-intensity spot at the output end is located below the core, the light emitted from the output end travels diagonally downwards, as shown in Figure 6C. Conversely, when the high-intensity spot at the output end is located above the core, the light emitted from the output end travels diagonally upwards.

[0023] FIG. 7A is a graph showing the NFP according to the position of the output end. The position of the output end is q shown in FIG. 7B １ ~q ６ . The horizontal axis corresponds to the vertical direction in FIG. 7B, and the vertical axis shows the intensity I normalized so that the maximum value is 1.

[0024] There is a spot with high intensity above the output end (q １ ~q ３ ), it can be seen that the intensity becomes maximum at some point in the region where x < 0 (hereinafter referred to as the first peak) (argmaxI(x) < 0), and the intensity becomes not maximum but maximum at some point in the region where x > 0 (hereinafter referred to as the second peak). Conversely, when there is a spot with high intensity below the output end (q ４ ~q ６ ), it can be seen that the first peak is in the region where x > 0 (argmaxI(x) > 0), and the second peak is in the region where x < 0.

[0025] This is the same even if the ratio of the fundamental mode to the first-order mode is changed from 50:50. FIGS. 8A to 8D are graphs showing the NFP when the mode ratios are 20:80, 40:60, 60:40, and 80:20, respectively.

[0026] FIG. 9A is a graph showing the simulation results of the far field pattern (FFP) of the light output from the optical fiber when the above-mentioned four parameters are randomly selected 24 times. Here, as shown in FIG. 9B, the FFP is the distribution of the intensity according to the angle θ from the axial direction of the optical fiber at a location away from the output end of the optical fiber. In FIG. 9A, the intensity I is normalized.

[0027] For each of the 24 FFPs, a change of variables from θ to φ (hereinafter referred to as the first change of variables) is performed. Specifically, θ ０ = argmaxI(θ), then when θ ０ > 0, φ = θ - θ ０ . On the other hand, when θ ０ < 0, φ = -(θ - θ０ Therefore, the first variable transformation is to set the horizontal axis θ such that the first peak is located on the vertical axis I (φ=0). ０ The graph is shifted to the right, and the horizontal axis φ is inverted as needed so that the second peak is located to the left of the vertical axis I (φ < 0). The first variable transformation yields the 24 intensity distributions I(φ) shown in Figure 10. Note that the condition "the second peak is located to the left of the vertical axis I" can be replaced with a condition such as "the intensity distribution I(φ) decreases monotonically to the right of the vertical axis I (φ > 0)."

[0028] Furthermore, for each of the 24 I(φ), a variable transformation from φ to γ ​​(hereinafter referred to as the second variable transformation) is performed. Specifically, I(φ) = I １ φ satisfying the condition φ １ gamma １ Let be any positive real number, then γ = (γ １ / φ １ )φ. For example, I １ = 1 / e ２ (This value is often used in the definition of beam diameter, etc.), γ １ = 30. The second variable transformation is the desired point (γ １ , I １ The horizontal axis φ is set to γ ​​so that the graph passes through ) １ / φ １ This involves doubling. The second variable transformation yields the 24 intensity distributions I(γ) shown in Figure 11. Note that γ = (γ １ / φ １ )φ and φ = ±(θ - θ) ０ ) From this, γ = ±(γ １ / φ １ ) (θ - θ) ０ Therefore, the variable transformation from θ to γ ​​is a one-dimensional affine transformation. Also, if i(θ) is the unnormalized intensity, then I(θ) = i(θ) / maxi(θ). Therefore, the transformation from i(θ) to I(γ) is a two-dimensional affine transformation.

[0029] Furthermore, the conversion result from I(θ) to I(γ) described above does not depend on the position of the output terminal. This can be confirmed by the fact that the six I(γ) obtained by converting the six I(θ) shown in Figure 12A are identical as shown in Figure 12B. Here, the six I(θ) are obtained by fixing the four parameters mentioned above to one value and positioning the output terminal q as shown in Figure 7B. １ ~q ６ These were selected from the following.

[0030] For each of the 24 I(γ) obtained in this way, I(γ) = I ２ γ that satisfies (hereafter referred to as FFP feature γ) ２ We will find the following: ２ ≠I １ For example, I ２ = 0.4. Figure 13 shows the γ obtained from 24 I(γ). １ and worst-case coupling efficiency η Ｗ This graph shows the relationship between γ. Figure 14 is a graph in which the number of samples is increased from 24 to 128, instead of omitting the transformation process. In both graphs, γ ２ and η Ｗ A positive correlation can be observed between them. Therefore, γ ２ From the value of η Ｗ It is possible to calculate an estimated value of γ and determine whether the coupling efficiency is above a certain threshold value based on whether the FFP features are above a predetermined value. For example, if the threshold value for coupling efficiency is 0.6, ２ You should select an optical fiber with a value of approximately 19.1 or higher.

[0031] Note that this correlation is γ １ It does not depend on the value of γ. １ If we multiply the value by k, we get γ ２ The value of γ is also multiplied by k, and the slope of the regression line becomes 1 / k, but the correlation coefficient does not change. Therefore, the normalized FFP feature γ is used as the FFP feature. ２ / γ １ (Calculating this value means γ １ Let γ be set to = 1 ２ You may also use (which is equivalent to calculating ). If φ(I) is the inverse function of I(φ) for φ≧0, then γ ２ / γ１ = φ(I) ２ ) / φ(I １ ) Also, θ≧θ ０ ≥ 0 or θ ≤ θ ０ If θ(I) is the inverse function of I(θ) at <0, then γ ２ / γ １ = (θ(I) ２ ) - θ ０ ) / (θ(I １ ) - θ ０ Therefore, the FFP feature is the angle ratio of two points on the FFP to which the affine transformation is applied, as shown in Figure 15. ２ / θ １ For example, if the standard value for binding efficiency is 0.6, γ ２ / γ １ You should select an optical fiber with a value of approximately 0.638 or higher.

[0032] Worst-case coupling efficiency η Ｗ This represents the coupling efficiency η under the most stringent conditions in terms of coupling efficiency. The coupling efficiency η does not depend solely on the properties of the optical fiber. Therefore, by considering factors other than the optical fiber properties, it is possible to select an optical fiber that can achieve the desired coupling efficiency even under stringent conditions. Coupling efficiency η Ｗ The simulation to determine this is performed assuming the transceiver structure shown in Figure 16A. Although this transceiver structure differs from the transceiver structure shown in Figure 3 in the shape of the connector bodies 101 and 201, this difference does not affect FFP or coupling efficiency. Therefore, both transceiver structures can be considered identical (it is acceptable to assume that the shape of the connector bodies 101 and 201 in Figure 16A is simplified for convenience).

[0033] The worst-case scenario is achieved by, for example, two conditions. The first condition is that the axes of the receiving optical fiber 204 and the distributed refractive index lens 205 are misaligned from the axes of the transmitting optical fiber 104 and the distributed refractive index lens 105. The misalignment here is, for example, 6 μm. The second condition is that, as shown in Figure 16B, the FFP is most biased in the opposite direction (upward) to the misalignment (downward) of the first condition (q in Figure 7A). １ ya q ６) This means that while the binding efficiency changes depending on the bias of the FFP, the FFP features themselves do not change, as mentioned above.

[0034] "3. Judgment System" Figure 17 shows an example of the configuration of the judgment system 300. This judgment system 300 has a light source 310, an optical fiber 320, and a judge 330, and determines whether the characteristics of the optical fiber 320 are within an acceptable range. Connectors 321 for easy connection to the light source 310 and connectors 322 for easy connection to the judge 330 are provided at both ends of the optical fiber 320.

[0035] The light source 310 includes a laser diode 311. This laser diode 311 outputs light of a second wavelength, for example, 850 nm, to the optical fiber 320.

[0036] The optical fiber 320 is a graded-index optical fiber that propagates light of a second wavelength input from the light source 310 to the detector 330. Here, the optical fiber 320 propagates the fundamental mode and the first-order mode components. Incidentally, when light of a first wavelength, for example 1310 nm, is input to this optical fiber 320, only the fundamental mode is propagated.

[0037] The detector 330 comprises an FFP measurement unit 331, a signal processing unit 332, and a display unit 333. The FFP measurement unit 331 measures the FFP of the light output from the optical fiber 320.

[0038] Figure 18A schematically shows the fitting of the optical fiber 320 to the FFP measurement unit 331. The FFP measurement unit 331 has a fitting portion 331a into which the connector 321 is fitted, a light receiving portion 331b, and a movable portion 331c. As shown in Figure 18B, the movable portion 331c moves the light receiving portion 331b on a circumference centered on the output end of the optical fiber 320. As a result, the light receiving portion 331b measures the FFP of the light output from the optical fiber 320. The FFP of the light output from the optical fiber 320, measured in this way by the light receiving portion 331b and therefore the FFP measurement unit 331, is sent to the signal processing unit 332 via a control line. Note that the configuration of the FFP measurement unit 331 is not limited to the configuration example shown in Figure 17B.

[0039] Returning to Figure 17, the signal processing unit 332 includes a receiving unit and receives FFP from the FFP measurement unit 331. The signal processing unit 332 comprises an intensity normalization unit 332a, a first variable conversion unit 332b, a second variable conversion unit 332c, and a determination unit 332d. Here, the processing performed on the FFP in the intensity normalization unit 332a, the first variable conversion unit 332b, and the second variable conversion unit 332c is an example of affine transformation.

[0040] The strength standardization unit 332a performs a process to standardize the FFP received from the FFP measurement unit 331 so that the maximum strength value is 1. The first variable conversion unit 332b applies the first variable conversion described above to the FFP processed by the strength standardization unit 332a. The second variable conversion unit 332c applies the second variable conversion described above to the FFP processed by the first variable conversion unit 332b.

[0041] The determination unit 332d includes a determination information calculation unit and calculates determination information from the FFP processed by the second variable conversion unit 332c. Here, the determination information may include the FFP feature quantities and the coupling efficiency estimated from the FFP feature quantities, as mentioned above. The determination unit 332d also determines whether the characteristics of the optical fiber 320 are within an acceptable range based on the determination information. The determination unit 330 may be configured so that the user can specify the FFP feature quantities and coupling efficiency that represent the boundary of the acceptable range. For example, if the reference value for coupling efficiency is 0.6, the determination unit 332d determines that the characteristics of the optical fiber 320 are within an acceptable range when the FFP feature quantity is approximately 19.1 or more, or when the normalized FFP feature quantity is approximately 0.638 or more, or when the worst-case coupling efficiency is 0.6 or more. The determination result of the determination unit 332d is sent to the display unit 333 as the output of the signal processing unit 332. The determination unit 332d may also output determination information to the display unit 333 in addition to the determination result.

[0042] Furthermore, the configuration of the signal processing unit 332, the processing performed by the signal processing unit 332, and their order are not limited to those described above, as long as equivalent results can be obtained. For example, by noting that I(•) = i(•) / maxi(•), mathematically equivalent processing can be performed even without the intensity normalization unit 332a. Also, the first variable transformation and the second variable transformation can be combined into a single mathematically equivalent variable transformation. In this way, various mathematically equivalent variations are available.

[0043] The display unit 333 displays the judgment result, and in addition, judgment information, on the display to inform the user. The display unit 333 is an example of a notification unit. Alternatively, instead of displaying the judgment result on the display, or in addition to displaying it, it is also conceivable to inform the user of the judgment result using voice, buzzer sound, lamp, vibration, or a combination thereof.

[0044] Thus, in the determination system 300, the determination device 330 measures the FFP of the light output from the optical fiber 320, and based on this FFP, it is determined whether or not the characteristics of the optical fiber 320 are within an acceptable range, and the determination result is notified to the user. The determination device 330 may be configured to display determination information rather than the determination result on the display unit 333. In this case, the determination of whether or not the characteristics of the optical fiber 320 are within an acceptable range may be made by the user from the displayed determination information, and the determination unit 332d may be replaced by a determination information calculation unit that calculates determination information from the FFP processed by the second variable conversion unit 332c. Furthermore, although it was explained above that the normalized FFP feature quantity is also calculated from the FFP processed by the second variable conversion unit 332c, this normalized FFP feature quantity does not necessarily have to be calculated from the FFP processed by the second variable conversion unit 332c, and can also be calculated from the FFP processed by the intensity normalization unit 332a. Alternatively, the determination device 330 may be configured so that the signal processing unit 332 can receive FFP from another device (external device), and it may determine whether the characteristics of the optical fiber related to this FFP are within an acceptable range.

[0045] "4. Processing Procedure" The flowchart in Figure 19 shows an example of the processing procedure on the light source 310 side and the judge 330 side in the judgment system 300.

[0046] In step ST1, the light source 310 starts outputting light from the laser diode 311. Meanwhile, in step ST11, the determination device 330 starts the determination process.

[0047] Next, in step ST12, the determination device 330 measures the FFP of the light output from the optical fiber 320 using the FFP measurement unit 331.

[0048] Next, in step ST13, the judgment unit 330 receives the FFP sent from the FFP measurement unit 331 by the signal processing unit 332 and determines whether the FFP is appropriate. Inappropriate FFPs include those containing a lot of noise or those with little bias in the intensity distribution. For example, in Figure 18B, if high-intensity spots are distributed in the depth direction (perpendicular to the horizontal axis direction of the FFP) within the optical fiber 320, the FFP will be almost symmetric (almost an even function), with the first peak appearing near the vertical axis and the second peak not appearing. In such cases, the user is asked to twist the optical fiber 320 or otherwise make the direction of the bias in the intensity distribution and the horizontal axis direction of the FFP as parallel as possible, and then the FFP is remeasured. For appropriate FFPs, the intensity normalization unit 332a performs a process to normalize the intensity so that the maximum value becomes 1.

[0049] Next, in step ST14, the determination unit 330 performs a process in which the first variable conversion is applied to the FFP processed by the strength standardization unit 332a using the first variable conversion unit 332b.

[0050] Next, in step ST15, the determination unit 330 performs a process in which the second variable conversion unit 332c applies the second variable conversion to the FFP processed by the first variable conversion unit 332b.

[0051] Next, in step ST16, the determination unit 330 calculates determination information such as FFP features and coupling efficiency based on the FFP processed by the second variable conversion unit 332c using the determination unit 332d, and uses this determination information to determine whether or not the characteristics of the optical fiber 320 are within an acceptable range.

[0052] Next, in step ST17, the determination device 330 displays the determination result from the determination unit 332d, as well as determination information, on the display unit 333 to inform the user whether or not the characteristics of the optical fiber 320 are within an acceptable range.

[0053] Next, in step ST18, the determination device 330 terminates the determination process. Meanwhile, in step ST2, the light source 310 stops the light output from the laser diode 311.

[0054] The determination start in the judgment device 310 may be performed based on the start of light output from the light source 310 to the judgment device 330. The light output stop in the light source 310 may be performed based on the determination end information or measurement end information from the judgment device 330 to the light source 310. Alternatively, the start or stop of light output may be performed based on manual operation by the user.

[0055] "5. Example of Computer Hardware Configuration" The processing in the signal processing unit 332 can be executed by hardware, but it can also be executed by software. When a series of processes are executed by software, the programs that make up the software are installed from a recording medium on a computer that has dedicated hardware built in, or on a general-purpose computer that can perform various functions by installing various programs.

[0056] Figure 20 is a block diagram showing an example of the hardware configuration of computer 600. Computer 600 includes a CPU 601, ROM 602, RAM 603, bus 604, input / output interface 605, input unit 606, output unit 607, storage unit 608, drive 609, connection port 610, and communication unit 611. Note that the hardware configuration shown here is just one example, and some of the components may be omitted. Furthermore, it may include components other than those shown here.

[0057] The CPU 601 functions, for example, as an arithmetic processing unit or control unit, and controls the overall operation or part thereof of each component based on various programs recorded in the ROM 602, RAM 603, storage unit 608, or removable recording medium 701.

[0058] ROM 602 is a means for storing programs loaded into the CPU 601 and data used for calculations. RAM 603 temporarily or permanently stores, for example, programs loaded into the CPU 601 and various parameters that change as needed when executing those programs.

[0059] The CPU 601, ROM 602, and RAM 603 are interconnected via the bus 604. Meanwhile, various components are connected to the bus 604 via the input / output interface 605.

[0060] The input unit 606 can be, for example, a mouse, keyboard, touch panel, button, switch, or lever. Furthermore, the input unit 606 may also be a remote controller (hereinafter referred to as a remote control) capable of transmitting control signals using infrared rays or other radio waves.

[0061] The output unit 607 may be a device capable of visually or audibly notifying the user of the acquired information, such as a display device like a CRT (Cathode Ray Tube), LCD, or organic EL; an audio output device like a speaker or headphones; a printer, a mobile phone, or a facsimile.

[0062] The storage unit 608 is a device for storing various types of data. Examples of storage units 608 include magnetic storage devices such as hard disk drives (HDDs), semiconductor storage devices, optical storage devices, or magneto-optical storage devices.

[0063] The drive 609 is a device that reads information recorded on a removable recording medium 701, such as a magnetic disk, optical disk, magneto-optical disk, or semiconductor memory, or writes information to the removable recording medium 701.

[0064] The removable recording medium 701 may be, for example, DVD media, Blu-ray® media, HD DVD media, or various semiconductor storage media. Of course, the removable recording medium 701 may also be, for example, an IC card equipped with a contactless IC chip, or an electronic device.

[0065] The connection port 610 is a port for connecting external devices 502, such as a USB (Universal Serial Bus) port, an HDMI (High-Definition Multimedia Interface) port, an IEEE 1394 port, a SCSI (Small Computer System Interface), an RS-232C port, or an optical audio terminal. The external devices 702 are, for example, a printer, a portable music player, a digital camera, a digital video camera, or an IC recorder.

[0066] The communication unit 611 is a communication device for connecting to the network 703, and is, for example, a communication card for wired or wireless LAN, Bluetooth®, or WUSB (Wireless USB), a router for optical communication, a router for ADSL (Asymmetric Digital Subscriber Line), or a modem for various types of communication.

[0067] The programs executed by the computer may be programs that are processed chronologically in the order described herein, or they may be programs that are processed in parallel or at necessary times, such as when a call is made.

[0068] As explained above, this technology calculates determination information based on the FFP of the light output from the optical fiber to determine whether the characteristics of the optical fiber are within an acceptable range, making it possible to determine whether the characteristics of the optical fiber are within an acceptable range at low cost.

[0069] "6. Variations" Note that an example with a first wavelength of 1310 nm was described. However, since laser light sources and LED light sources can be used as light sources, the first wavelength may be, for example, between 300 nm and 5 μm.

[0070] An example was given where the first wavelength is 1310 nm, but this first wavelength may be in the 1310 nm band including 1310 nm, 1550 nm, or the 1550 nm band including 1550 nm. Similarly, an example was given where the second wavelength is 850 nm, but this second wavelength may be in the 850 nm band including 850 nm.

[0071] While an example of double-mode optical communication has been described, the scope of application of this technology is not limited to this.

[0072] Although an example of a graded-index optical fiber was described, the optical waveguide may also be a stepped-index optical fiber, or an optical waveguide other than an optical fiber, such as a silicon optical waveguide.

[0073] If the bias in the measured intensity distribution is small, the user may be asked to twist the FFP measurement unit 331 instead of the optical fiber 320. Alternatively, the optical fiber 320 or the FFP measurement unit 331 may be twisted by a motor on behalf of the user. Furthermore, if the FFP measurement unit 331 is movable to measure FFP in multiple (orthogonal) directions, remeasurement can be avoided by using an FFP with a large bias or by estimating the actual biased direction of the FFP from FFP in multiple directions. In addition, if the measured FFP contains noise or outliers, smoothing, outlier removal, and remeasurement may be performed.

[0074] I １ = 1 / e ２ and I ２ = 0.4 and θ １ and θ ２ We have explained the case where the first peak is located on the opposite side from the second peak, but this technique is not limited to this if a correlation can be confirmed between FFP features and binding efficiency. For example, I １ ≥I ２ It may also be θ １ and θ ２ At least one of the two peaks may be located between the first and second peaks, or beyond the second peak. Furthermore, while we have described the case where the correlation is expressed by a linear function, correlations based on any function can be assumed. １ , I ２ By selecting a value and performing regression analysis using an appropriate function, the selected parameter (I １ , I ２ It is possible to easily verify whether the values ​​and functions are appropriate.

[0075] While preferred embodiments of the present disclosure have been described in detail above with reference to the attached drawings, the technical scope of the present disclosure is not limited to such examples. It is clear to any person with ordinary skill in the art of the present disclosure that various modifications or alterations may be conceived within the scope of the technical idea set forth in the claims, and these will naturally also fall within the technical scope of the present disclosure.

[0076] Also, the effects described in this specification are illustrative or exemplary only and not limiting. That is, the technology according to the present disclosure may exhibit other effects that are apparent to those skilled in the art from the description of this specification, together with or instead of the above effects.

[0077] In addition, this technology can also be configured as follows. (1) An information processing apparatus including a determination information calculation unit that calculates determination information for determining whether the characteristics of the optical fiber are within an acceptable range based on the far-field pattern (FFP) of the light output from the optical fiber. (2) The determination information calculation unit calculates the determination information based on the first, second, and third angles on the FFP, and the first, second, and third angles are different from each other. The information processing apparatus according to (1). (3) The FFP has a first peak where the intensity is maximum, and the first angle is the angle corresponding to the first peak. The information processing apparatus according to (2). (4) The FFP has a second peak where the intensity is maximum, the second peak is different from the first peak, and at least one of the second and third angles is located on the opposite side of the angle corresponding to the second peak across the first angle. The information processing apparatus according to (3). (5) The information processing apparatus according to claim (4), where the second and third angles are located on the opposite side of the angle corresponding to the second peak across the first angle. (6) The determination information calculation unit calculates the determination information based on the ratio of the difference between the second angle and the first angle and the difference between the third angle and the first angle. The information processing apparatus according to any one of (2) to (5). (7) The second angle is the angle at which the intensity on the FFP becomes 1 / e ２ times the maximum value. The information processing apparatus according to any one of (2) to (6). (8) The third angle is the angle at which the intensity on the FFP becomes 1 / e ２(7) The information processing apparatus according to (7), wherein the angle is a predetermined value greater than twice the maximum value. (9) The information processing apparatus according to (7), wherein the third angle is an angle on the FFP at which the intensity is 0.4 times the maximum value. (10) The information processing apparatus according to any one of (1) to (9), wherein the determination information calculation unit calculates the determination information based on the result of applying an affine transformation to the FFP. (11) The information processing apparatus according to (10), wherein the FFP has a first peak at which the intensity is maximum, and the affine transformation includes a variable transformation corresponding to a first angle corresponding to the first peak. (12) The information processing apparatus according to (10) or (11), wherein the affine transformation includes a variable transformation to pass a predetermined point through the FFP. (13) The information processing apparatus according to any one of (1) to (12), wherein the characteristic affects the coupling efficiency of a system in which the optical fiber is used as the transmitting optical fiber. (14) The information processing apparatus according to (13), wherein the focal point on the receiving side of the light output from the transmitting optical fiber is offset in the radial direction of the receiving optical fiber from the axis of the receiving optical fiber of the system. (15) The information processing apparatus according to any one of (1) to (14), wherein the optical fiber is a graded index type optical fiber or a step index type optical fiber. (16) The information processing apparatus according to any one of (1) to (15), further comprising a measurement unit for measuring the FFP. (17) The information processing apparatus according to any one of (1) to (16), further comprising a determination unit for determining whether the characteristics are within an acceptable range using the determination information. (18) The information processing apparatus according to any one of (1) to (17), further comprising a notification unit for notifying the user of the determination information. (19) An information processing method having a procedure for calculating determination information for determining whether the characteristics of the optical fiber are within an acceptable range based on the far-field pattern (FFP) of the light output from the optical fiber. (20) A program that causes a computer to function as a determination information calculation means for calculating determination information for determining whether the characteristics of the optical fiber are within an acceptable range based on the far-field pattern (FFP) of the light output from the optical fiber.

[0078] 10T, 10R, 104, 204, 320... Optical fiber 10a... Core 10b... Cladding 11T, 11R, 102, 105, 202, 205... Lens 101, 201... Connector body 103, 203... Optical fiber insertion hole 300... Judgment system 310... Light source 311... Laser diode 321, 322... Connector 330... Judgment unit 331... FFP measurement unit 331a... Mating unit 331b... Light receiving unit 331c... Movable unit 332... Signal processing unit 332a... Strength standardization unit 332b... First variable conversion unit 332c... Second variable conversion unit 332d... Judgment unit 333... Display unit 600... Computer

Claims

1. An information processing device comprising: a receiving unit that receives the far-field pattern (FFP) of light output from an optical fiber; and a determination information calculation unit that calculates determination information for determining whether the characteristics of the optical fiber are within an acceptable range based on the FFP.

2. The determination information calculation unit calculates the determination information based on the first, second, and third angles on the FFP, and the first, second, and third angles are different from each other.

3. The information processing apparatus according to claim 2, wherein the FFP has a first peak at which the intensity is maximum, and the first angle is the angle corresponding to the first peak.

4. The information processing apparatus according to claim 3, wherein the FFP has a second peak at which the intensity is maximum, and unlike the first peak, at least one of the second and third angles is located on the opposite side of the first angle from the angle corresponding to the second peak.

5. The information processing apparatus according to claim 4, wherein the second and third angles are located on the opposite side of the first angle from the angle corresponding to the second peak.

6. The information processing apparatus according to claim 2, wherein the determination information calculation unit calculates the determination information based on the ratio of the difference between the second angle and the first angle and the difference between the third angle and the first angle.

7. The second angle is 1 / e of the maximum intensity on the FFP. ２ The information processing apparatus according to claim 2, wherein the angle is doubled.

8. The third angle is 1 / e of the maximum intensity on the FFP. ２ The information processing apparatus according to claim 7, wherein the angle is a predetermined value greater than twice the original value.

9. The information processing apparatus according to claim 7, wherein the third angle is the angle on the FFP at which the intensity is 0.4 times the maximum value.

10. The information processing apparatus according to claim 1, wherein the determination information calculation unit calculates the determination information based on the result of applying an affine transformation to the FFP.

11. The information processing apparatus according to claim 10, wherein the FFP has a first peak at which the intensity is maximum, and the affine transformation includes a variable transformation corresponding to a first angle corresponding to the first peak.

12. The information processing apparatus according to claim 10, wherein the affine transformation includes a variable transformation to cause the FFP to pass through a predetermined point.

13. The information processing apparatus according to claim 1, wherein the aforementioned characteristics affect the coupling efficiency of a system in which the optical fiber is used as the transmitting optical fiber.

14. The information processing apparatus according to claim 13, wherein the focal point of the light output from the transmitting optical fiber on the receiving side is offset in the radial direction of the receiving optical fiber from the axis of the receiving optical fiber of the system.

15. The information processing apparatus according to claim 1, wherein the optical fiber is a graded-index optical fiber.

16. The information processing apparatus according to claim 1, further comprising a measuring unit for measuring the FFP.

17. The information processing apparatus according to claim 1, further comprising a determination unit that determines whether or not the characteristics are within an acceptable range using the determination information.

18. The information processing apparatus according to claim 1, further comprising a notification unit for notifying the user of the determination information.

19. An information processing method comprising the steps of receiving a far-field pattern (FFP) of light output from an optical fiber, and calculating determination information for determining whether the characteristics of the optical fiber are within an acceptable range based on the FFP.

20. A program that causes a computer to function as a determination information calculation means for calculating determination information to determine whether the characteristics of an optical fiber are within an acceptable range based on the far-field pattern (FFP) of light output from the optical fiber.

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