JPH05268191A - Optical feeder - Google Patents

Abstract

PURPOSE:To prevent excess loss by polarizing a continuous light from a feeding side and sending the light through an optical fiber, separating two polarized light components at feeding receiving side and applying photoelectric conversion to them. CONSTITUTION:A laser diode(LD) 10 being a feeder side light source is driven by a drive circuit so as to generate a continuous light and the continuous light is polarized by a polarized light controller 11. The light polarized by the polarized light caller 11 is sent to a feeding reception side via a constant polarization fiber 12, in this case, the constant polarized wave fiber 12 is called the polarized wave preservation fiber, through which two polarized wave components vibrated mutually in a plane perpendicular to the travelling direction in the orthogonal direction are sent. Then the two polarized light components are separated by a polarized beam splitter 13 at a feeding reception side, the polarized light components are subjected to photoelectric conversion by photodiodes PD1, PD2 and converted into a DC voltage by a transformer T and a rectifier circuit 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical power feeding device for feeding power via an optical fiber.

[0002]

2. Description of the Related Art In general, an optical power feeding device for feeding power through an optical fiber is used when electric wires cannot be laid in a dangerous area such as a chemical plant. This optical power supply device basically converts light to electric power by a powerful light source on the power supply side to generate optical energy, transmits this optical power through an optical fiber, and photoelectrically converts the optical power on the power supply side by a photodiode or a solar cell. By converting, it is comprised so that it may be converted into electric energy.

However, in such an optical power transmission system, a loss due to electric-optical conversion on the power feeding side, a transmission loss due to an optical fiber, and a loss due to optical-electrical conversion on the power-supplied side are large, and particularly optical-electrical conversion. Due to the large loss due to, various improvements have been proposed to improve efficiency.

FIG. 6 shows a conventional optical power feeder. On the power feeding side, continuous light is generated by the laser diode (LD) 1 and transmitted through the optical fiber 2. On the powered side,
A plurality of photodiodes PD1 to PDn are connected in series, and the light transmitted from the power supply side through the optical fiber 2 is split by the optical path splitter 3, and each split light is received by the photodiodes PD1 to PDn. It is focused on the surface.

FIG. 7 shows another conventional example. This device
It is disclosed in Japanese Patent Laid-Open No. 3-61818. In this case, the transformer T is used on the power-supplied side, and the photodiode PD and the rectifier circuit are used on the primary side and the secondary side of the transformer T, respectively. Then, in order to drive the transformer T, the laser diode 1 on the power feeding side is pulse-emitted, and the generated rectangular wave light is transmitted through the optical fiber 2,
The photodiode PD on the power-supplied side is blinked to generate an alternating current on the primary side of the transformer T. This AC is a transformer T
After being boosted by, it is converted into direct current by the rectifier circuit 4.

[0006]

However, as shown in FIG. 6, in an optical power feeding device in which a plurality of photodiodes PD1 to PDn are connected in series on the power-supplied side, excess loss when splitting by the optical path splitter 3 is caused. Since there is a series resistance component of the photodiodes PD1 to PDn, there is a problem of poor efficiency.

Further, as shown in FIG. 7, in the optical power supply device using the transformer T on the power-supplied side, pulsed light for driving the transformer T, that is, light having a power smaller than continuous light is transmitted. There is a problem that the efficiency cannot be improved so much as compared with continuous light.

[0008] Therefore, an object of the present invention is to provide an optical power feeding device capable of improving the transmission efficiency of optical power.

[0009]

The optical power feeding device of the present invention comprises:
A light source for generating continuous light, a polarization means for polarizing the continuous light of the light source, an optical fiber for transmitting two polarization components polarized by the polarization means, and two polarizations transmitted through the optical fiber It is configured to include a polarized light separating unit that separates the components and a photoelectric conversion unit that photoelectrically converts each polarized light component separated by the polarized light separating unit.

[0010]

The continuous light generated by the light source on the power feeding side is polarized by the polarization means and transmitted through the optical fiber. On the power-supplied side, two polarization components are separated by the polarization separation means, and each polarization component is photoelectrically converted. Therefore, excess loss that occurs when splitting is performed by the optical path splitter of the conventional example is suppressed, and the transmission efficiency of optical power is improved as compared with the case of transmitting pulsed light.

[0011]

1 is a block diagram showing an embodiment of an optical power feeding device according to the present invention. In the figure, a laser diode (LD) 10 which is a light source on the power feeding side is driven by a drive circuit (not shown) so as to generate continuous light. This continuous light is polarized by the polarization controller 11. The polarization controller 11 includes a polarization control element 11a and the polarization control element 1
Modulation driver 11b for polarizing the continuous light of the laser diode 10 by modulating 1a.

The light polarized by the polarization controller 11 is
It is transmitted to the power-supplied side via the polarization maintaining fiber 12. The constant polarization fiber 12 is also called a polarization maintaining fiber, and can transmit two polarization components vibrating in directions orthogonal to each other in a plane perpendicular to the traveling direction.

The above two polarization components are separated by the polarization beam splitter 13 on the power-supplied side, and the respective polarization components are photo-electrically converted by the photodiodes PD1 and PD2, respectively, and converted into a DC voltage by the transformer T and the rectifier circuit 14. To be done.

According to this embodiment, continuous light is polarized and transmitted from the power feeding side, and two polarization components are separated and photoelectrically converted on the power fed side. Therefore, an optical path splitter as shown in FIG. 6 is used. While preventing excessive loss when dividing by 3,
It is possible to transmit a larger power (theoretically double) than that in the case of transmitting the pulsed light as shown in FIG.

In the above embodiment, the two polarization components polarized by the polarization controller 11 are configured to be transmitted via the polarization maintaining fiber 12, but as shown in FIG.
The two polarization components are respectively converted into ordinary optical fibers 12a and 12
It may be configured to transmit via b.

In the above embodiment, the current photo-electrically converted by the photodiodes PD1 and PD2 is converted into a DC voltage by the transformer T and the rectifying circuit 14, but as shown in FIG. A double voltage rectifier circuit may be used. In this voltage doubler rectifier circuit, the current photoelectrically converted by the photodiodes PD1 and PD2 is charged in the capacitor C1 and smoothed by the smoothing capacitor C2.

Next, FIG. 4 shows a second embodiment. In this embodiment, as a light source, a plurality (n) of laser diodes 101 to 1 for generating laser beams having different wavelengths .lambda.1 to .lambda.n are used.
0n is used. The laser lights having the wavelengths λ1 to λn are combined by the combiner 15, polarized by the polarization controller 11, and transmitted through the constant polarization fiber 12.

The laser light transmitted to the power-supplied side is demultiplexed by the demultiplexer 16 into wavelengths λ1 each having two polarization components.
~ Demultiplexed to λn laser light. Then, the two polarization components of each laser beam are divided into beam splitters 131 to 1 respectively.
Separated by 3n, each pair of laser diodes (PD1
1, PD12) to (PDn1, PDn2) are photoelectrically converted.

According to this second embodiment, since n laser diodes 101 to 10n are used, it is possible to transmit n times the power of the first embodiment. Further, as compared with the case of transmitting the pulsed light in FIG. 7 described above, theoretically, 2n times the power can be transmitted.

Next, FIG. 5 shows a third embodiment. In this embodiment, a data transmission system is added to the first embodiment. That is, when the optical power is transmitted from the power supply side coupler 21 to the power supply side coupler 22 via the polarization maintaining fiber 12 by the device of the first embodiment,
Power is supplied to the power-supplied side.

The data on the power-supplied side detected and generated by this power source is transmitted from the transmitter 23, optically modulated by the modulation driving device 24, and further polarized by the polarization control device 25.
It is transmitted to the coupler 21 on the power feeding side via the coupler 22 and the constant polarization fiber 12. On the power supply side, the polarization for the data is discriminated by the polarization discriminating device 26, photoelectrically converted by the photodiode 27, and received by the receiver 28.

According to the third embodiment, the transmission efficiency of the optical power can be improved, and the constant polarization fiber 12 for transmitting the optical power can also be used for the data transmission.

[0023]

As described above, according to the present invention, continuous light is polarized from the feeding side and transmitted through the optical fiber, and two polarized components are separated on the fed side and each polarized component is photoelectrically converted. Since the conversion is performed, it is possible to prevent excess loss that occurs when the light is split by the optical path splitter as in the conventional example, and it is possible to improve the optical power transmission efficiency as compared with the case of transmitting pulsed light.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an optical power feeding device according to the present invention.

FIG. 2 is a configuration diagram showing a modified example of the constant polarization fiber of FIG.

FIG. 3 is a configuration diagram showing a modified example of the rectifying means in FIG.

FIG. 4 is a block diagram showing a second embodiment.

FIG. 5 is a block diagram showing a third embodiment.

FIG. 6 is a schematic configuration diagram showing a conventional optical power supply device.

FIG. 7 is a schematic configuration diagram showing another conventional example.

[Explanation of symbols]

10, 101 to 10n ... Laser diode, 11 ... Polarization controller, 12 ... Constant polarization fiber, 12a, 12b ... Optical fiber, 13, 131 to 13n ... Polarization beam splitter, PD1, PD2, (PD11, PD12) to ( PDn1,
PDn2) ... Photodiode.

Claims (1)

[Claims] 1. A light source for generating continuous light, a polarizing means for polarizing the continuous light generated by the light source, an optical fiber for transmitting two polarization components polarized by the polarizing means, and an optical fiber via the optical fiber. An optical power feeding device comprising: a polarized light separating unit that separates two transmitted polarized light components; and a photoelectric conversion unit that photoelectrically converts each polarized light component separated by the polarized light separating unit.