Power receiving device, optical power supply system, and power receiving method

Abstract

This power receiving device is provided with: a first light receiving unit that converts incident power supply light into electrical power; a second light receiving unit that converts the power supply light into an electrical signal; and a demodulation unit that demodulates the electrical signal converted by the second light receiving unit to obtain information. The information is superimposed on the power supply light in advance by modulation.

Description

[Technical Field]

[0001] The present disclosure relates to a power receiving device, an optical power feeding system, and a power receiving method. [Background technology]

[0002] Recently, optical power supply systems have been studied in which electric power is converted into light (called power supply light) and transmitted, and the power supply light is converted into electrical energy for use as electric power. Patent Document 1 describes an optical communication device including: an optical transmitter that transmits signal light modulated with an electrical signal and power supply light for supplying electric power; an optical fiber having a core that transmits the signal light, a first cladding formed around the core and having a refractive index smaller than that of the core, and that transmits the power supply light, and a second cladding formed around the first cladding and having a refractive index smaller than that of the first cladding; and an optical receiver that operates with electric power converted from the power supply light transmitted through the first cladding of the optical fiber, and converts the signal light transmitted through the core of the optical fiber into the electric signal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-135989 Summary of the Invention [Problem to be solved by the invention]

[0004] In an optical power supply system, it would be useful if power and information could be transmitted simultaneously by inserting information into the power supply light. The present disclosure aims to simultaneously transmit power and information via powered light. [Means for solving the problem]

[0005] The power receiving device according to the present disclosure comprises: a first light receiving unit that converts incident power supply light into electric power; a second light receiving unit that converts the power supply light into an electrical signal; a demodulation unit that demodulates the electrical signal converted by the second light receiving unit to acquire information; Equipped with The information is pre-superimposed on the power supply light by modulation. 、 The second light receiving unit converts the power supply light reflected by the light receiving surface of the first light receiving unit into an electric signal. . In addition, the power receiving device according to the present disclosure includes: a first light receiving unit that converts incident power supply light into electric power; a second light receiving unit that converts the power supply light into an electrical signal; a demodulation unit that demodulates the electrical signal converted by the second light receiving unit to acquire information; Equipped with The information is superimposed in advance on the power supply light by modulation, The second light receiving section converts the power supply light that has passed through a light receiving surface of the first light receiving section into an electric signal.

[0006] The optical power supply system according to the present disclosure includes: Equipped with a power supply device and a power receiving device, the power supply device outputs power supply light on which information is superimposed by modulation; The power receiving device is a first light receiving unit that converts the incident power supply light into electric power; a second light receiving unit that converts the power supply light reflected by the light receiving surface of the first light receiving unit into an electric signal; a demodulation unit that demodulates the electrical signal converted by the second light receiving unit to acquire the information; It has. In addition, the optical power supply system according to the present disclosure includes: Equipped with a power supply device and a power receiving device, the power supply device outputs power supply light on which information is superimposed by modulation; The power receiving device is a first light receiving unit that converts the incident power supply light into electric power; a second light receiving unit that converts the power supply light that has passed through a light receiving surface of the first light receiving unit into an electric signal; a demodulation unit that demodulates the electrical signal converted by the second light receiving unit to acquire the information; It has.

[0007] The power receiving method according to the present disclosure includes: receiving, by a first light receiving unit, the power supply light on which information has been superimposed by modulation in advance, and converting the light into electric power; a step of receiving the power supply light reflected by the light receiving surface of the first light receiving unit with a second light receiving unit and converting the light into an electrical signal; demodulating the electrical signal converted by the second light receiving unit to obtain the information; Includes. Further, the power receiving method according to the present disclosure includes: receiving, by a first light receiving unit, the power supply light on which information has been superimposed by modulation in advance, and converting the light into electric power; receiving the power supply light transmitted through the light receiving surface of the first light receiving unit with a second light receiving unit and converting the light into an electrical signal; demodulating the electrical signal converted by the second light receiving unit to obtain the information; Includes. [Effects of the Invention]

[0008] According to the present disclosure, power and information can be transmitted simultaneously via power supply light. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a configuration diagram of an optical power supply system according to a first embodiment of the present disclosure. [Figure 2] 4A to 4C are diagrams illustrating an example of an output waveform of power supply light according to the first embodiment of the present disclosure. [Figure 3A] FIG. 2 is a diagram showing a light receiving chamber according to the first embodiment of the present disclosure. [Figure 3B] FIG. 10 is a diagram showing a modified example of a light receiving chamber according to the first embodiment of the present disclosure. [Figure 3C] FIG. 10 is a diagram showing a modified example of a light receiving chamber according to the first embodiment of the present disclosure. [Figure 3D] FIG. 10 is a diagram showing a modified example of a light receiving chamber according to the first embodiment of the present disclosure. [Figure 4] FIG. 10 is a configuration diagram of an optical power supply system according to a second embodiment of the present disclosure. [Figure 5A] 10A to 10C are diagrams illustrating modified examples of a light receiving chamber according to the second embodiment of the present disclosure. [Figure 5B]10A to 10C are diagrams illustrating modified examples of a light receiving chamber according to the second embodiment of the present disclosure. [Figure 5C] 10A to 10C are diagrams illustrating modified examples of a light receiving chamber according to the second embodiment of the present disclosure. [Figure 6] FIG. 10 is a configuration diagram of an optical power supply system according to a third embodiment of the present disclosure. [Figure 7] FIG. 10 is a configuration diagram of an optical power supply system according to a third embodiment of the present disclosure, illustrating an optical connector and the like. [Figure 8A] 5A to 5C are diagrams illustrating modified examples of the second light receiving section according to the first embodiment of the present disclosure. [Figure 8B] 5A to 5C are diagrams illustrating modified examples of the second light receiving section according to the first embodiment of the present disclosure. [Figure 8C] 5A to 5C are diagrams illustrating modified examples of the second light receiving section according to the first embodiment of the present disclosure. [Figure 9A] 10A to 10C are diagrams illustrating modifications of the second light receiving section according to the second embodiment of the present disclosure. [Figure 9B] 10A to 10C are diagrams illustrating modifications of the second light receiving section according to the second embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings.

[0011] [First embodiment] 1, an optical power supply system 1A of this embodiment includes a power supply device (PSE: Power Sourcing Equipment) 110 and a power receiving device (PD: Powered Device) 310. The optical power supply system 1A transmits power supply light 112 generated by the power supply device 110 to the power receiving device 310 through space. Such an optical power supply method of space transmission is called PoA (Power over Air). In the present disclosure, the power supply device is a device that converts electric power into optical energy and supplies the converted energy, and the power receiving device is a device that receives optical energy and converts the optical energy into electric power. In addition, in the present disclosure, electric power and information (data) are transmitted by the power supply light.

[0012] The power supply device 110 includes a power supply semiconductor laser 111 and a power supply control unit 150 . The power supply device 110 is connected to a power source, and the power supply semiconductor laser 111 and the like are electrically driven. The power supply semiconductor laser 111 oscillates with the power from the power supply and outputs power supply light 112 . The power supply device 110 has a lens 115 such as a collimator lens, and transmits power supply light 112 emitted from the power supply semiconductor laser 111 into space via the lens 115. Note that the lens 115 may not be necessary if the spread of the power supply light 112 is small.

[0013] The power supply control unit 150 controls the laser oscillation of the power supply semiconductor laser 111 to control the output of the power supply light 112. The power supply control unit 150 pulse-modulates the laser output of the power supply light 112 to superimpose information on the power supply light 112. Specifically, as shown in FIG. 2, the power supply control unit 150 changes the output of the power supply light 112 into a pulsed form based on the information to be transmitted, to generate an output variation portion Pw of the pulse waveform. At this time, the power supply control unit 150 maintains a predetermined base output (fundamental output) Pb and superimposes the output variation portion Pw of the pulse waveform on the base output Pb. However, the base output Pb does not have to be constant. Although FIG. 2 shows an example in which the laser output is binarized, it is also possible to perform higher-order digital modulation with more multi-values, or analog modulation. Furthermore, there is no particular limitation on the information to be superimposed on the power supply light 112. For example, it may be a signal that notifies the power receiving device 310 of the power transmission state of the power supply device 110 (such as a signal to increase the amount of power supply from now on), or a signal that controls the device of the power receiving device 310 (or an external device).

[0014] The power receiving device 310 includes a light receiving chamber 312 that receives the power supply light 112 from the power supply device 110 . The light receiving chamber 312 has a lens 313, such as a parallel plate or condenser lens, that has no power, at an opening 312b in the wall on the power supply device 110 side. The power supply light 112 from the power supply device 110 passes through the lens 313 and enters the light receiving chamber 312. However, the light receiving chamber 312 may not have the lens 313, and the power supply light 112 may enter directly inside.

[0015] As shown in FIG. 3A, the light receiving chamber 312 accommodates two light receiving sections 311 (first light receiving section 311a and second light receiving section 311b) which are photoelectric conversion elements. Of these, the first light receiving unit 311a is disposed in a portion of the light receiving chamber 312 facing the lens 313 (opening 312b). The power supply light 112 that passes through the lens 313 and enters the light receiving chamber 312 first enters the first light receiving unit 311a. The first light receiving unit 311a converts the power supply light 112 that enters its light receiving surface 311af into electric power. The electric power converted by the first light receiving unit 311a is used as the driving power required within the power receiving device 310. Furthermore, the power receiving device 310 may output the electric power converted by the first light receiving unit 311a to an external device.

[0016] The second light-receiving unit 311b is disposed in the light-receiving chamber 312 on a wall portion on a side of the first light-receiving unit 311a and in the vicinity thereof. The second light-receiving unit 311b converts the power supply light 112 (reflected light 113) that is reflected by the light-receiving surface 311af of the first light-receiving unit 311a and incident on its own light-receiving surface 311bf into an electrical signal. As a result, the surplus portion of the power supply light 112 that was not converted into power by the first light-receiving unit 311a (i.e., the reflected light 113) is converted by the second light-receiving unit 311b, and an electrical signal having a pulse signal corresponding to the output change portion Pw is obtained. The position of the second light receiving unit 311b in the light receiving chamber 312 is not particularly limited as long as it is a position where the reflected light 113 is incident. For example, the second light receiving unit 311b may be arranged side by side with the first light receiving unit 311a as shown in Fig. 3B, or may be arranged on a wall portion facing the first light receiving unit 311a as shown in Fig. 3C. 3D, a partition wall 312c may be provided in the light-receiving chamber 312 to separate the first light-receiving unit 311a and the second light-receiving unit 311b. The second light-receiving unit 311b may be located on any wall of the light-receiving chamber 312, as long as it is located on the opposite side of the partition wall 312c from the first light-receiving unit 311a. A light-guiding unit 312d for passing the reflected light 113 may be formed in the partition wall 312c. The light-guiding unit 312d is, for example, a through-hole such as a pinhole. An optical system for focusing the reflected light 113 passing through the light-guiding unit 312d onto the second light-receiving unit 311b may be provided near the light-guiding unit 312d.

[0017] The inner wall surface 312a of the light receiving chamber 312 has a matte finish with numerous irregularities that diffuse light. Instead of (or in addition to) having a matte finish on the inner wall surface 312a, the inner wall surface 312a may be colored with a high light absorption rate (or a low light reflectance rate). The coloring method is not particularly limited. Here, "a color with a high light absorption rate" includes, for example, black or a color similar to black. Furthermore, the portion of the inner wall surface 312a that is matte or has a high absorption rate does not have to be the entire surface, as long as it includes at least a portion of the surface. The second light receiving unit 311b (photoelectric conversion element) generates electrical output with a resolution corresponding to the light intensity, so if the incident light is too strong, it may be difficult to extract information. Therefore, by diffusing or absorbing the reflected light 113 and appropriately weakening it using the inner wall surface 312a, which is configured with a matte finish or a color with high absorption, the second light receiving unit 311b can extract information more effectively. In this case, the configuration that determines the degree of diffusion or absorption at the inner wall surface 312a (the specific configuration of the matte finish or the color depth, etc.) should be determined according to the photoelectric conversion characteristics of the second light receiving unit 311b, including the positional relationship between the second light receiving unit 311b and the first light receiving unit 311a. Furthermore, in some cases, information can be extracted more effectively by detecting the photoelectric conversion in the second light receiving unit 311b using voltage in areas with weak light and current in areas with strong light.

[0018] The second light receiving unit 311b may be any unit that converts the power supply light 112 incident on the power receiving device 310 into an electric signal. In other words, the power supply light 112 incident on the second light receiving unit 311b is not limited to the light reflected by the light receiving surface 311af of the first light receiving unit 311a. For example, as shown in FIG. 8A, the second light receiving section 311b may convert the power supply light 112 (transmitted light 114) transmitted through the first light receiving section 311a (light receiving surface 311af thereof) into an electric signal. In this case, the second light receiving unit 311b is disposed, for example, on the rear side of the first light receiving unit 311a (the side opposite the light receiving surface 311af) so as to be close to (or in contact with) the first light receiving unit 311a. As a result, the transmitted light 114 leaking from the rear side of the first light receiving unit 311a is converted by the second light receiving unit 311b, and an electrical signal is obtained. The position of the second light receiving unit 311b is not particularly limited as long as it is a position where the transmitted light 114 is incident, and may be, for example, on the side of the first light receiving unit 311a. The size of the second light receiving unit 311b may be smaller than that of the first light receiving unit 311a. 8B, a light-shielding plate 311ag (including a reflector, etc.) may be disposed on the back surface of the first light-receiving unit 311a, and a hole 311ah such as a pinhole or a slit may be provided in the light-shielding plate 311ag. The light-shielding plate 311ag may be disposed between the first light-receiving unit 311a and the second light-receiving unit 311b. This allows the transmitted light 114 to pass through the hole 311ah, thereby controlling the position of the transmitted light 114, etc. 8C, the transmitted light 114 from the hole 311ah of the light-shielding plate 311ag may be incident on the second light-receiving unit 311b, and the transmitted light 114 from portions other than the light-shielding plate 311ag may be incident on the optical waveguide 316. The transmitted light 114 may be guided (condensed) on the light-entering surface of the optical waveguide 316. This allows the surplus transmitted light 114 other than that incident on the second light-receiving unit 311b to be used as another signal source. In this case, a shutter (not shown) may be disposed between the optical waveguide 316 and the first light-receiving unit 311a, and information may be superimposed on the transmitted light 114 by opening and closing the shutter.

[0019] As shown in FIG. 1, the power receiving device 310 also includes a demodulation circuit 370 outside the light receiving chamber 312. The demodulation circuit 370 demodulates the electrical signal (i.e., the pulse signal corresponding to the output change portion Pw) converted from the power supply light 112 by the second light receiving unit 311b, and acquires the information that was previously superimposed on the power supply light 112. Depending on the content of the information, the acquired information is output to the control unit of the power receiving device 310 or an external device.

[0020] Each of the power supply semiconductor laser 111 and the two light receiving units 311 is a photoelectric conversion element including a laser medium with a laser wavelength of 500 nm or less. More specifically, the semiconductor material constituting the semiconductor region that produces the optical-electrical conversion effect of the power supply semiconductor laser 111 and the two light receiving units 311 is a semiconductor with a short laser wavelength of 500 nm or less. Semiconductors with short laser wavelengths have a large band gap and high photoelectric conversion efficiency, which improves the photoelectric conversion efficiency on both the power generation side and the power receiving side of optical power supply, thereby improving the optical power supply efficiency. For this purpose, the semiconductor material may be, for example, a semiconductor material of a laser medium with a laser wavelength (fundamental wave) of 200 to 500 nm, such as diamond, gallium oxide, aluminum nitride, or GaN. In addition, a semiconductor having a band gap of 2.4 eV or more is used as the semiconductor material. For example, semiconductor materials for the laser medium, such as diamond, gallium oxide, aluminum nitride, and GaN, having a band gap of 2.4 to 6.2 eV, may be used. Note that the longer the wavelength of laser light, the better the transmission efficiency, and the shorter the wavelength, the better the photoelectric conversion efficiency. Therefore, for long-distance transmission, a semiconductor material for the laser medium with a laser wavelength (fundamental wave) of greater than 500 nm may be used. Furthermore, if photoelectric conversion efficiency is prioritized, a semiconductor material for the laser medium with a laser wavelength (fundamental wave) of less than 200 nm may be used. These semiconductor materials may be applied to at least one of the power supply semiconductor laser 111 and the two light receiving sections 311. This improves the photoelectric conversion efficiency on the power supply side or the power receiving side, and improves the optical power supply efficiency.

[0021] As described above, according to the first embodiment, the power supply light 112 incident on the first light receiving unit 311a is converted into electric power by the first light receiving unit 311a. Meanwhile, the power supply light 112 incident on the second light receiving unit 311b is converted into an electric signal by the second light receiving unit 311b. Then, this electric signal is demodulated by the demodulation circuit 370, and information that was previously superimposed on the power supply light 112 is obtained. This allows power and information to be transmitted simultaneously via the power supply light 112.

[0022] Furthermore, according to this embodiment, the second light receiving section 311b converts the power supply light 112 (reflected light 113) reflected by the light receiving surface 311af of the first light receiving section 311a into an electric signal. This allows the main part of the power supply light 112 to be suitably converted into power by the first light receiving unit 311a, while allowing information to be suitably extracted from the surplus part (i.e., reflected light 113) that has not been converted into power by the first light receiving unit 311a.

[0023] Furthermore, according to this embodiment, the first light receiving section 311 a and the second light receiving section 311 b are housed in the same light receiving chamber 312 . This allows the first light receiving section 311a and the second light receiving section 311b to be disposed close to each other, and allows the reflected light 113 from the first light receiving section 311a to be preferably incident on the second light receiving section 311b.

[0024] Furthermore, according to this embodiment, inner wall surface 312a of light receiving chamber 312 has irregularities that diffuse light, is colored to have a high light absorption rate, or has both of these configurations. This allows the reflected light 113 reflected by the first light receiving portion 311a to be diffused or absorbed by the inner wall surface 312a and suitably weakened. Therefore, the reflected light 113 having an intensity corresponding to the photoelectric conversion characteristics of the second light receiving portion 311b can be made incident on the second light receiving portion 311b, and ultimately, information can be suitably extracted from the reflected light 113.

[0025] Furthermore, according to this embodiment, the power supply light 112 has a predetermined base power Pb superimposed with an output change portion Pw modulated with information. Therefore, it is possible to stably obtain at least the power corresponding to the base output Pb through photoelectric conversion of the power supply light 112 in the first light receiving portion 311a.

[0026] Furthermore, according to this embodiment, the second light receiving section 311b may convert the power supply light 112 (transmitted light 114) that has passed through the light receiving surface 311af of the first light receiving section 311a into an electric signal. This allows the main part of the power supply light 112 to be suitably converted into power by the first light receiving unit 311a, while allowing information to be suitably extracted from the surplus part (i.e., transmitted light 114) that has not been converted into power by the first light receiving unit 311a. In this case, the second light receiving section 311b can be disposed close to the first light receiving section 311a, which in turn allows the power receiving device 310 to be configured compactly. Furthermore, in this case, since it is easy to make transmitted light 114 from first light receiving portion 311a incident on second light receiving portion 311b, second light receiving portion 311b can be smaller than first light receiving portion 311a, and therefore second light receiving portion 311b can be made to have a faster response.

[0027] Furthermore, according to this embodiment, the light shielding plate 311ag arranged between the first light receiving portion 311a and the second light receiving portion 311b may have a hole portion 311ah that allows the power supply light 112 (transmitted light 114) that has passed through the light receiving surface 311af of the first light receiving portion 311a to pass through. This allows the transmitted light 114 to pass through the hole 311ah, and the position of the transmitted light 114 can be suitably controlled.

[0028] Furthermore, according to this embodiment, the feeding light 112 (transmitted light 114) that has passed through the light receiving surface 311af of the first light receiving portion 311a may be made incident on the optical waveguide 316. This allows the transmitted light 114 to be used as another signal source.

[0029] Second Embodiment As shown in Fig. 4, the optical power supply system 1B of this embodiment includes a power supply device 110, an optical fiber cable 200, and a power receiving device 310. The optical power supply system 1B transmits power supply light 112 generated by the power supply device 110 to the power receiving device 310 via the optical fiber cable 200. This type of optical power supply method is called power over fiber (PoF). The optical power supply system 1B of this embodiment differs from the first embodiment in that the power supply light 112 is transmitted via the optical fiber cable 200.

[0030] The optical fiber cable 200 includes an optical fiber 250 that forms a transmission path for the power supply light. The optical fiber cable 200 has one end 201 connectable to the power supply device 110 and the other end 202 connectable to the power receiving device 310, and transmits power supply light 112. In the power supply device 110, the power supply control unit 150 pulse-modulates the laser output of the power supply light 112, thereby outputting the power supply light 112 on which information is superimposed. The power supply light 112 from the power supply device 110 is input to one end 201 of the optical fiber cable 200, propagates through the optical fiber 250, and is output from the other end 202 to the power receiving device 310.

[0031] The power supply light 112 output from the optical fiber cable 200 to the power receiving device 310 is incident on the first light receiving unit 311a in the light receiving chamber 312 and converted into electric power. Of the power supply light 112 incident on the light receiving chamber 312, that reflected by the light receiving surface 311af of the first light receiving unit 311a (reflected light 113) is converted into an electric signal by the second light receiving unit 311b and demodulated by the demodulation circuit 370, and information that was previously superimposed on the power supply light 112 is obtained.

[0032] The power supply semiconductor laser 111 and the two light receiving units 311 each contain the same semiconductor material as in the first embodiment as the semiconductor material that forms the semiconductor region that exhibits the optical-electrical conversion effect, thereby achieving high optical power supply efficiency.

[0033] The optical power supply system 1B configured as above can also achieve the same effects as those of the first embodiment.

[0034] 5A, the optical fiber 250 may be inserted into the light-receiving chamber 312 (for example, immediately before the first light-receiving unit 311a). The light-emitting surface 251 of the optical fiber 250 faces the light-receiving surface 311af of the first light-receiving unit 311a. In other words, the direction of light emitted from the light-emitting surface 251 is approximately perpendicular to the light-receiving surface 311af. However, the direction of light emitted from the light-emitting surface 251 may be inclined with respect to the light-receiving surface 311af of the first light-receiving unit 311a. 5B, the second light receiving unit 311b may be housed in a second light receiving chamber 315 connected to the light receiving chamber 312 via a connecting light path 314 that propagates light. The inner wall surfaces of the connecting light path 314 and the second light receiving chamber 315 may be formed with an uneven matte finish and / or a color with high light absorption, similar to the inner wall surface 312a of the light receiving chamber 312.

[0035] 5C, the optical fiber 250 may be directly connected to two light receiving units 311 without providing the light receiving chamber 312. In this case, the first light receiving unit 311a has its light receiving surface 311af located close to and facing the light output surface 251 of the optical fiber 250. The second light receiving unit 311b has its light receiving surface 311bf facing a portion of the waveguide of the optical fiber 250 that is upstream of the light output surface 251 in the direction of the power supply light 112. With this configuration, the light receiving chamber 312 is omitted, resulting in a simple configuration, and the second light receiving section 311b can be arranged relatively freely in the longitudinal direction of the optical fiber 250.

[0036] The second light receiving section 311b may be disposed at a position where it can suitably avoid (do not block) the light (feed light 112) irradiated from the optical fiber 250 to the first light receiving section 311a. 9A, the second light receiving unit 311b may be disposed outside the irradiation range R of the light emitted from the light output surface 251 of the optical fiber 250. The irradiation range R is a cone-shaped range whose central axis is the emission direction LD of the light from the light output surface 251 of the optical fiber 250 and whose apex angle is twice the emission angle θ of the light. The emission angle θ is defined by the following equation (1). NA=n sinθ (1) Here, NA is the numerical aperture of the optical fiber 250, and n is the refractive index of air (≈1).

[0037] 9B, the second light receiving unit 311b may be disposed as close as possible to the reflection trajectory RT of light emitted from the light output surface 251 of the optical fiber 250 in the emission direction LD (emission center) and specularly reflected by the light receiving surface 311af. In this embodiment, the second light receiving unit 311b is disposed within a predetermined distance from the reflection trajectory RT. This allows the reflected light 113 distributed more widely on the reflection trajectory RT to be preferably incident on the second light receiving portion 311b, thereby increasing the amount of light received by the second light receiving portion 311b. For ease of understanding, FIG. 9B illustrates a state in which the emission direction LD is inclined with respect to the light receiving surface 311af. However, when the emission direction LD is perpendicular to the light receiving surface 311af, the emission direction LD and the reflected trajectory RT substantially coincide with each other.

[0038] Furthermore, the second light receiving portion 311b may be disposed as close as possible to the intersection PI between the light receiving surface 311af and the emission direction LD of the light from the light emitting surface 251 of the optical fiber 250. This allows the reflected light 113, which is more distributed around the intersection point PI between the light emission direction LD and the light receiving surface 311af, to be preferably incident on the second light receiving portion 311b, thereby increasing the amount of light received by the second light receiving portion 311b.

[0039] Third Embodiment As shown in FIG. 6, the optical power supply system 1C of this embodiment includes a power supply system via optical fiber and an optical communication system, and includes a first data communication device 100 including a power supply device (PSE: Power Sourcing Equipment) 110, an optical fiber cable 200C, and a second data communication device 300 including a power receiving device (PD: Powered Device) 310. The power supply device 110 includes a power supply semiconductor laser 111 and a power supply control unit 150. The first data communication device 100 includes a receiving unit 130 in addition to the power supply device 110. The first data communication device 100 corresponds to a data terminal equipment (DTE), a repeater, etc. The receiving unit 130 includes a signal photodiode 131.

[0040] The optical fiber cable 200C includes an optical fiber 250C having a core 210C that forms a transmission path for signal light, and a clad 220C that is disposed around the core 210C and forms a transmission path for feed light.

[0041] The power receiving device 310 includes a light receiving chamber 312 that houses two light receiving units 311, and a demodulation circuit 370. The second data communication device 300 includes, in addition to the power receiving device 310, a transmission unit 320 and a data processing unit 340. The second data communication device 300 corresponds to a power end station or the like. The transmission unit 320 includes a signal semiconductor laser 321 and a modulator 322. The data processing unit 340 is a unit that processes the received signal. The second data communication device 300 is a node in a power supply network. Alternatively, the second data communication device 300 may be a node that communicates with other nodes.

[0042] The first data communication device 100 is connected to a power source, and the power supply semiconductor laser 111, the signal photodiode 131, etc. are electrically driven. The first data communication device 100 is a node in a power supply network. Alternatively, the first data communication device 100 may be a node that communicates with other nodes. The power supply semiconductor laser 111 oscillates using power from the power supply and outputs power supply light 112. At this time, the power supply control unit 150 controls the laser oscillation of the power supply semiconductor laser 111 to pulse-modulate the laser output of the power supply light 112, thereby superimposing information on the power supply light 112.

[0043] The first light receiving unit 311a converts the power supply light 112 transmitted through the optical fiber cable 200C into electric power. The obtained electric power is used as driving power for the transmitting unit 320 and the data processing unit 340, as well as for driving power required for other components of the second data communication device 300. Furthermore, the second data communication device 300 may be capable of outputting the obtained electric power to an external device. The second light receiving unit 311b converts the power supply light 112 (reflected light 113) reflected by the light receiving surface 311af of the first light receiving unit 311a into an electrical signal. The demodulation circuit 370 demodulates the electrical signal converted by the second light receiving unit 311b and extracts information that was previously superimposed on the power supply light 112. The acquired information is output to the data processing unit 340 or an external device depending on its content.

[0044] The data processing unit 340 transmits input data to the node, while receiving data from the node and outputting it to the modulator 322 as transmit data 324 . A modulator 322 of the transmitting section 320 modulates laser light 323 from a signal semiconductor laser 321 based on transmission data 324 and outputs the modulated laser light 323 as signal light 325 . The signal photodiode 131 of the receiving unit 130 demodulates the signal light 325 transmitted through the optical fiber cable 200C into an electrical signal and outputs it. Data in the form of the electrical signal is transmitted to the node. The data from the node may be used as information that the power supply control unit 150 controls the power supply semiconductor laser 111 to superimpose on the power supply light 112.

[0045] The power supply light 112 from the first data communication device 100 is input to one end 201C of the optical fiber cable 200C, propagates through the cladding 220C, and is output to the second data communication device 300 from the other end 202C. A signal light 325 from the second data communication device 300 is input to the other end 202C of the optical fiber cable 200C, propagates through the core 210C, and is output to the first data communication device 100 from one end 201C.

[0046] 7, the first data communication device 100 is provided with an optical input / output unit 140 and an optical connector 141 attached thereto. The second data communication device 300 is provided with an optical input / output unit 350 and an optical connector 351 attached thereto. An optical connector 230C attached to one end 201C of an optical fiber cable 200C is connected to the optical connector 141. An optical connector 240C attached to the other end 202C of the optical fiber cable 200C is connected to the optical connector 351. The optical input / output unit 140 guides the power supply light 112 to the clad 220C and guides the signal light 325 to the receiving unit 130. The optical input / output unit 350 guides the power supply light 112 to the power receiving device 310 and guides the signal light 325 to the core 210C. As described above, the optical fiber cable 200C has one end 201C connectable to the first data communication device 100 and the other end 202C connectable to the second data communication device 300, and transmits the power supply light 112. Furthermore, in this embodiment, the optical fiber cable 200C transmits the signal light 325.

[0047] The power supply semiconductor laser 111 and the two light receiving units 311 each contain the same semiconductor material as in the first embodiment as the semiconductor material that forms the semiconductor region that exhibits the optical-electrical conversion effect, thereby achieving high optical power supply efficiency.

[0048] It is also possible to provide separate optical fibers for transmitting the signal light 325 and the power supply light 112. The optical fiber cable 200C may also be configured with multiple fibers. Alternatively, one of the signal light 325 and the power supply light 112 may be transmitted through space using the PoA method, and the other may be transmitted through an optical fiber using the PoF method. Furthermore, the power supply light 112 may be transmitted through optical fiber in some sections and through space in other sections. A lens such as a collimator lens may be disposed at the beginning of the space transmission section. A lens such as a condenser lens or a diffusing lens may be disposed at the end of the optical fiber transmission section.

[0049] The above describes the embodiments of the present disclosure. However, the content of the present disclosure is not limited to the above embodiments. The details shown in the embodiments can be modified as appropriate without departing from the spirit of the invention.

[0050] An embodiment of the present disclosure will be described below. (1) The power receiving device is a first light receiving unit that converts incident power supply light into electric power; a second light receiving unit that converts the power supply light reflected by the light receiving surface of the first light receiving unit into an electric signal; a demodulation unit that demodulates the electrical signal converted by the second light receiving unit to acquire information; Equipped with The information is previously superimposed on the power supply light by modulation.

[0051] (2) In the power receiving device described in (1) above, a light receiving chamber that accommodates the first light receiving unit and the second light receiving unit therein; The light receiving chamber has an opening, at a portion facing the light receiving surface of the first light receiving portion, through which the power supply light is incident from outside.

[0052] (3) In the power receiving device described in (2) above, The inner wall surface of the light receiving chamber has irregularities that diffuse light, or is made of a color that has a high light absorption rate, or has both of these configurations.

[0053] (4) In any of the power receiving devices (1) to (3) above, The power supply light has a predetermined basic output superimposed with an output change portion modulated with the information.

[0054] (5) In any of the power receiving devices (1) to (4) above, an optical fiber for transmitting the power supply light; the first light receiving unit has a light receiving surface facing the light exit surface of the optical fiber; The second light receiving portion has a light receiving surface facing a waveguide portion of the optical fiber that is upstream of the light output surface and is in contact with the power supply light.

[0055] (6) In any of the power receiving devices (1) to (5) above, Each of the first light receiving section and the second light receiving section is a photoelectric conversion element including a laser medium with a laser wavelength of 500 nm or less.

[0056] (7) The optical power supply system is Equipped with a power supply device and a power receiving device, the power supply device outputs power supply light on which information is superimposed by modulation; The power receiving device is a first light receiving unit that converts the incident power supply light into electric power; a second light receiving unit that converts the power supply light reflected by the light receiving surface of the first light receiving unit into an electric signal; a demodulation unit that demodulates the electrical signal converted by the second light receiving unit to acquire the information; It has.

[0057] (8) How to receive power: receiving, by a first light receiving unit, the power supply light on which information has been superimposed by modulation in advance, and converting the light into electric power; a step of receiving the power supply light reflected by the light receiving surface of the first light receiving unit with a second light receiving unit and converting the light into an electrical signal; demodulating the electrical signal converted by the second light receiving unit to obtain the information; Includes. [Industrial Applicability]

[0058] As described above, the present invention is useful for simultaneously transmitting power and information via power supply light. [Explanation of symbols]

[0059] 1A, 1B, 1C Optical Power Supply System 110 Power supply equipment 111 Power supply semiconductor laser 112 Power supply light 113 Reflected light 114 Transmitted light 150 Power supply control unit 250, 250C optical fiber 251 Idemitsu surface 310 Power receiving device 311 Light receiving part 311a 1st light receiving section 311af light receiving surface 311ag light shielding plate 311ah hole 311b 2nd light receiving section 311bf light receiving surface 312 Light receiving chamber 312a Inner wall 312b aperture 316 Optical waveguide 370 Demodulation circuit (demodulation section) Pb Base output (basic output) Pw Output change part R illumination range θ Output angle

Claims

1. a first light receiving unit that converts incident power supply light into electric power; a second light receiving unit that converts the power supply light into an electrical signal; a demodulation unit that demodulates the electrical signal converted by the second light receiving unit to acquire information; Equipped with The information is superimposed in advance on the power supply light by modulation, the second light receiving unit converts the power supply light reflected by the light receiving surface of the first light receiving unit into an electrical signal. Power receiving device.

2. a light receiving chamber that accommodates the first light receiving unit and the second light receiving unit therein; the light receiving chamber has an opening through which the power supply light is incident from the outside, in a portion facing the light receiving surface of the first light receiving unit; The power receiving device according to claim 1 .

3. The inner wall surface of the light receiving chamber has irregularities that diffuse light, is configured to have a color that has a high light absorption rate, or has both of these configurations. The power receiving device according to claim 2 .

4. an optical fiber for transmitting the power supply light; the first light receiving unit has a light receiving surface facing the light exit surface of the optical fiber; The second light receiving unit has a light receiving surface facing a waveguide portion of the optical fiber that is upstream of the power supply light from the light output surface. The power receiving device according to claim 1 .

5. an optical fiber that transmits the power supply light to the first light receiving unit; the second light receiving unit is disposed outside an irradiation range of light emitted from the light exit surface of the optical fiber, The irradiation range is a cone-shaped range having a vertex angle that is twice the emission angle θ defined by the following formula (1): The power receiving device according to claim 1 . NA=n・sinθ...(1) however, NA: Numerical aperture of the optical fiber n: refractive index of air

6. a first light receiving unit that converts incident power supply light into electric power; a second light receiving unit that converts the power supply light into an electrical signal; a demodulation unit that demodulates the electrical signal converted by the second light receiving unit to acquire information; Equipped with The information is superimposed in advance on the power supply light by modulation, the second light receiving unit converts the power supply light transmitted through a light receiving surface of the first light receiving unit into an electrical signal. Power receiving device.

7. a light blocking plate disposed between the first light receiving unit and the second light receiving unit; the light-shielding plate has a hole through which the power supply light that has passed through the light-receiving surface of the first light-receiving unit passes. The power receiving device according to claim 6 .

8. an optical waveguide into which the feeding light transmitted through the light receiving surface of the first light receiving unit is incident; The power receiving device according to claim 6 .

9. The power supply light has a predetermined basic output and an output change portion modulated with the information superimposed thereon. The power receiving device according to claim 1 or 6.

10. each of the first light receiving unit and the second light receiving unit is a photoelectric conversion element including a laser medium having a laser wavelength of 500 nm or less; The power receiving device according to claim 1 or 6.

11. Equipped with a power supply device and a power receiving device, the power supply device outputs power supply light on which information is superimposed by modulation; The power receiving device is a first light receiving unit that converts the incident power supply light into electric power; a second light receiving unit that converts the power supply light reflected by a light receiving surface of the first light receiving unit into an electrical signal; a demodulation unit that demodulates the electrical signal converted by the second light receiving unit to acquire the information; having Optical power supply system.

12. Equipped with a power supply device and a power receiving device, the power supply device outputs power supply light on which information is superimposed by modulation; The power receiving device is a first light receiving unit that converts the incident power supply light into electric power; a second light receiving unit that converts the power supply light that has passed through a light receiving surface of the first light receiving unit into an electrical signal; a demodulation unit that demodulates the electrical signal converted by the second light receiving unit to acquire the information; having Optical power supply system.

13. receiving, by a first light receiving unit, the power supply light on which information has been superimposed by modulation in advance, and converting the light into electric power; a step of receiving the power supply light reflected by the light receiving surface of the first light receiving unit with a second light receiving unit and converting the light into an electrical signal; demodulating the electrical signal converted by the second light receiving unit to obtain the information; A power receiving method including:

14. receiving, by a first light receiving unit, the power supply light on which information has been superimposed by modulation in advance, and converting the light into electric power; receiving the power supply light transmitted through a light receiving surface of the first light receiving unit with a second light receiving unit and converting the light into an electrical signal; demodulating the electrical signal converted by the second light receiving unit to obtain the information; A power receiving method including:

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