Patent Description:
Recently, there has been studied an optical power supply system that converts electric power into light called feed light, transmits the feed light, converts the feed light into electric energy, and uses the electric energy as electric power.

There is disclosed in <CIT> an optical communication device that includes: an optical transmitter that transmits signal light modulated with an electric signal and feed light for supplying electric power; an optical fiber including a core that transmits the signal light, a first cladding that is formed around the core, has a refractive index lower than that of the core, and transmits the feed light, and a second cladding that is formed around the first cladding, and has a refractive index lower than that of the first cladding; and an optical receiver that operates with electric power obtained by converting the feed 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.

<CIT>discloses an optical data communication and power converter device, comprising: a receiver circuit comprising an optical receiver including a photovoltaic device and a photoconductive device arranged within an area that is configured for illumination by a modulated optical signal emitted from a monochromatic light source of a transmitter circuit, wherein the photovoltaic device is configured to generate electric current responsive to the illumination of the area by the modulated optical signal, and wherein the photoconductive device is configured to generate a data signal distinct from the electric current responsive to the illumination of the area by the modulated optical signal.

<CIT> discloses a photovoltaic cell comprising: a rear contact; and a first cell having a first band-gap energy supported by said rear contact, said first cell comprising InxGaySbz, wherein x+y+z=<NUM> and z ranges from <NUM> to <NUM>.

<CIT> discloses a device according to the preamble of claim <NUM>.

<CIT> discloses an optical probe system comprising an optical probe having an optical converter circuit with an optoelectronic device. The optoelectronic device is arranged for converting a first radiation beam from a radiation source into electrical energy and for receiving first data comprised in said first radiation beam. The optical converter circuit is powerable by said electric energy in the first radiation beam. The optoelectronic device is further arranged for emitting a second radiation beam towards a photodetector, said emission being inducible by the incoming first radiation beam, the second radiation beam comprising second data.

In optical power supply, further improvement of optical power supply efficiency is required. For that, for example, improvement of photoelectric conversion efficiency at the power supplying side and the power receiving side is required.

The present invention provides a device in combination with a first optical fiber cable according to claim <NUM>, an optical power supply system according to claim <NUM>, an optical power supply system according to claim <NUM>, an optical power supply system according to claim <NUM>, and an optical power supply system according to claim <NUM>.

The accompanying drawings are not intended as a definition of the limits of the invention but illustrate embodiments of the invention, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the invention, wherein:.

Hereinafter, one or more embodiments of the present disclosure will be described with reference to the drawings. The scope of the present invention is defined by the claims.

As shown in <FIG>, a power over fiber (PoF) system 1A (optical power supply system) of this embodiment includes a power sourcing equipment (PSE) device <NUM>, an optical fiber cable 200A and a powered device (PD) <NUM>.

In the present disclosure, a PSE device converts electric power into optical energy and supplies (sources) the optical energy, and a powered device receives (draws) the supplied optical energy and converts the optical energy into electric power.

The PSE device <NUM> includes a semiconductor laser <NUM> for power supply.

The optical fiber cable 200A includes an optical fiber 250A that forms a transmission path of feed light.

The powered device <NUM> includes a photoelectric conversion element <NUM>.

The PSE device <NUM> is connected to a power source, and electrically drives the semiconductor laser <NUM> and so forth.

The semiconductor laser <NUM> oscillates with the electric power from the power source, thereby outputting feed light <NUM>.

The optical fiber cable 200A has one end 201A (first end) connectable to the PSE device <NUM> and the other end 202A (second end) connectable to the powered device <NUM> to transmit the feed light <NUM>.

The feed light <NUM> from the PSE device <NUM> is input to the one end 201A of the optical fiber cable 200A, propagates through the optical fiber 250A, and is output from the other end 202A of the optical fiber cable 200A to the powered device <NUM>.

The photoelectric conversion element <NUM> converts the feed light <NUM> transmitted through the optical fiber cable 200A into electric power. The electric power obtained by the conversion of the feed light <NUM> by the photoelectric conversion element <NUM> is driving power needed in the powered device <NUM>. The powered device <NUM> is capable of outputting, for an external device(s), the electric power obtained by the conversion of the feed light <NUM> by the photoelectric conversion element <NUM>.

Semiconductor materials of semiconductor regions of the semiconductor laser <NUM> and the photoelectric conversion element <NUM> are semiconductors having a laser wavelength being a short wavelength of <NUM> or less. The semiconductor regions exhibit light-electricity conversion effect.

Semiconductors having a laser wavelength being a short wavelength have a large band gap and a high photoelectric conversion efficiency, and hence improve photoelectric conversion efficiency at the power supplying side (PSE side) and the power receiving side (PD side) in optical power supply, and improve optical power supply efficiency.

Hence, as the semiconductor materials, laser media having a laser wavelength (base wave) of <NUM> to <NUM> may be used. Examples thereof include diamond, gallium oxide, aluminum nitride and gallium nitride.

Further, as the semiconductor materials, semiconductors having a band gap of <NUM> eV or greater are used.

For example, laser media having a band gap of <NUM> eV to <NUM> eV may be used. Examples thereof include diamond, gallium oxide, aluminum nitride and gallium nitride.

Laser light having a longer wavelength tends to have a higher transmission efficiency, whereas laser light having a shorter wavelength tends to have a higher photoelectric conversion efficiency. Hence, when laser light is transmitted for a long distance, laser media having a laser wavelength (base wave) of greater than <NUM> may be used, whereas when the photoelectric conversion efficiency is given priority, laser media having a laser wavelength (base wave) of less than <NUM> may be used.

Any of these semiconductor materials may be used in one of the semiconductor laser <NUM> and the photoelectric conversion element <NUM>. This improves the photoelectric conversion efficiency at either the PSE side or the PD side, and improves the optical power supply efficiency.

As shown in <FIG>, a power over fiber (PoF) system <NUM> of this embodiment includes a power supply system through an optical fiber and an optical communication system therethrough, and includes: a first data communication device <NUM> including a power sourcing equipment (PSE) device <NUM>; an optical fiber cable <NUM>; and a second data communication device <NUM> including a powered device (PD) <NUM>.

The PSE device <NUM> includes a semiconductor laser <NUM> for power supply. The first data communication device <NUM> includes, in addition to the PSE device <NUM>, a transmitter <NUM> and a receiver <NUM> for data communication. The first data communication device <NUM> corresponds to a data terminal equipment (DTE) device, a repeater or the like. The transmitter <NUM> includes a semiconductor laser <NUM> for signals and a modulator <NUM>. The receiver <NUM> includes a photodiode <NUM> for signals.

The optical fiber cable <NUM> includes an optical fiber <NUM> including: a core <NUM> that forms a transmission path of signal light; and a cladding <NUM> that is arranged so as to surround the core <NUM> and forms a transmission path of feed light.

The powered device <NUM> includes a photoelectric conversion element <NUM>. The second data communication device <NUM> includes, in addition to the powered device <NUM>, a transmitter <NUM> and a receiver <NUM> for data communication, and a data processing unit <NUM>. The second data communication device <NUM> corresponds to a power end station or the like. The transmitter <NUM> includes a semiconductor laser <NUM> for signals and a modulator <NUM>. The receiver <NUM> includes a photodiode <NUM> for signals. The data processing unit <NUM> processes received signals. The second data communication device <NUM> is a node in a communication network. The second data communication device <NUM> may be a node that communicates with another node.

The first data communication device <NUM> is connected to a power source, and electrically drives the semiconductor laser <NUM>, the semiconductor laser <NUM>, the modulator <NUM>, the photodiode <NUM> and so forth. The first data communication device <NUM> is a node in a communication network. The first data communication device <NUM> may be a node that communicates with another node.

The photoelectric conversion element <NUM> converts the feed light <NUM> transmitted through the optical fiber cable <NUM> into electric power. The electric power obtained by the conversion of the feed light <NUM> by the photoelectric conversion element <NUM> is driving power needed in the second data communication device <NUM>, for example, driving power for the transmitter <NUM>, the receiver <NUM> and the data processing unit <NUM>. The second data communication device <NUM> may be capable of outputting, for an external device(s), the electric power obtained by the conversion of the feed light <NUM> by the photoelectric conversion element <NUM>.

The modulator <NUM> of the transmitter <NUM> modulates laser light <NUM> output by the semiconductor laser <NUM> to signal light <NUM> on the basis of transmission data <NUM>, and outputs the signal light <NUM>.

The photodiode <NUM> of the receiver <NUM> demodulates the signal light <NUM> transmitted through the optical fiber cable <NUM> to an electric signal, and outputs the electric signal to the data processing unit <NUM>. The data processing unit <NUM> transmits data of the electric signal to a node, and also receives data from the node and outputs the data to the modulator <NUM> as transmission data <NUM>.

The modulator <NUM> of the transmitter <NUM> modulates laser light <NUM> output by the semiconductor laser <NUM> to signal light <NUM> on the basis of the transmission data <NUM>, and outputs the signal light <NUM>.

The photodiode <NUM> of the receiver <NUM> demodulates the signal light <NUM> transmitted through the optical fiber cable <NUM> to an electric signal, and outputs the electric signal. Data of the electric signal is transmitted to a node, whereas data from the node is the transmission data <NUM>.

The feed light <NUM> and the signal light <NUM> from the first data communication device <NUM> are input to one end <NUM> (first end) of the optical fiber cable <NUM>, propagate through the cladding <NUM> and the core <NUM>, respectively, and are output from the other end <NUM> (second end) of the optical fiber cable <NUM> to the second data communication device <NUM>.

The signal light <NUM> from the second data communication device <NUM> is input to the other end <NUM> of the optical fiber cable <NUM>, propagates through the core <NUM>, and is output from the one end <NUM> of the optical fiber cable <NUM> to the first data communication device <NUM>.

As shown in <FIG>, the first data communication device <NUM> includes a light input/output part <NUM> and an optical connector <NUM> attached to the light input/output part <NUM>, and the second data communication device <NUM> includes a light input/output part <NUM> and an optical connector <NUM> attached to the light input/output part <NUM>. An optical connector <NUM> provided at the one end <NUM> of the optical fiber cable <NUM> is connected to the optical connector <NUM>, and an optical connector <NUM> provided at the other end <NUM> of the optical fiber cable <NUM> is connected to the optical connector <NUM>. The light input/output part <NUM> guides the feed light <NUM> to the cladding <NUM>, guides the signal light <NUM> to the core <NUM>, and guides the signal light <NUM> to the receiver <NUM>. The light input/output part <NUM> guides the feed light <NUM> to the powered device <NUM>, guides the signal light <NUM> to the receiver <NUM>, and guides the signal light <NUM> to the core <NUM>.

As described above, the optical fiber cable <NUM> has the one end <NUM> connectable to the first data communication device <NUM> and the other end <NUM> connectable to the second data communication device <NUM> to transmit the feed light <NUM>. In this embodiment, the optical fiber cable <NUM> transmits the signal light <NUM>/<NUM> bidirectionally.

As the semiconductor materials of the semiconductor regions, which exhibit the light-electricity conversion effect, of the semiconductor laser <NUM> and the photoelectric conversion element <NUM>, any of those described in the first embodiment can be used, thereby achieving a high optical power supply efficiency.

Although some embodiments of the present disclosure have been described above, these embodiments are made for purposes of illustration and example only. The present invention can be carried out in various other forms, and each component may be omitted, replaced or modified without departing from the scope of the present invention.

For example, like an optical fiber cable 200B of a power over fiber system 1B shown in <FIG>, an optical fiber <NUM> that transmits signal light and an optical fiber <NUM> that transmits feed light may be provided separately. Further, the optical fiber cable 200B may be composed of a plurality of optical fiber cables.

Although power over fiber systems have been described, the present disclosure is applicable to optical power supply in general.

In an optical power supply system according to at least one embodiment of the present disclosure, a PSE device includes a semiconductor laser that oscillates with electric power, thereby outputting feed light, and includes a semiconductor region exhibiting the light-electricity conversion effect, wherein a semiconductor material of the semiconductor region is a laser medium having a laser wavelength of <NUM> or less.

In at least one embodiment, the semiconductor material is the laser medium having a band gap of <NUM> eV or greater.

In at least one embodiment, the semiconductor material is one selected from diamond, gallium oxide, aluminum nitride and gallium nitride.

In an optical power supply system according to at least one embodiment of the present disclosure, a powered device includes a photoelectric conversion element that converts feed light into electric power, and includes a semiconductor region exhibiting the light-electricity conversion effect, wherein a semiconductor material of the semiconductor region is a laser medium having a laser wavelength of <NUM> or less.

Claim 1:
A device (<NUM>) in combination with a first optical fiber cable (200A, <NUM>, <NUM>), the device (<NUM>) comprising
a power sourcing equipment semiconductor laser (<NUM>) configured to output a first light (<NUM>), configured to be used for power feeding, and including a semiconductor region exhibiting a light-electricity conversion effect, and
a first transmitter (<NUM>) configured to output a second light for communication,
wherein the first optical fiber cable (200A, <NUM>, 200B) has a first path configured for the first light to pass through,
wherein a semiconductor material of the semiconductor region is a laser medium having a laser wavelength of <NUM> or less, and
wherein the first optical fiber cable (200A, <NUM>, <NUM>) has a second path configured for the second light to pass through, or wherein the device is further in combination with a second optical fiber cable (<NUM>) having a second path configured for the second light to pass through.