JPH07146410A - Fluorescent fiber cable - Google Patents

Abstract

PURPOSE:To provide incidence/outgoing of light of plural wavelengths at desired continuous positions in a fluorescent fiber cable side surface and at the same positions by mixing two sorts of phosphor, and adding obtained mix to one of a core and a clad. CONSTITUTION:To a core 11, phosphor 13 having proper condensation, modulation, and amplification effect to radiate fluorescence of a wavelength of lambda2 by excitation light of lambda1 mixed with phosphor 14 having proper condensation, modulation, and amplification effect to radiate fluorescence of a wavelength lambda4 by excitation light of lambda3 is added uniformly. In the case where incidental light from an end surface is lambda1, it is absorbed by the phosphor 13 to radiate fluorescence of lambda2. This fluorescence of lambda2 is radiated isotropicly inside the core 11. When the incidental light from the end surface is lambda3, similarly, it is absorbed by the phosphor 14 to radiate florescent light of lambda4. This fluorescent light of lambda4 is radiated isotropically inside the core 11. Radiation to the external occurs continously along the whole circumference in the axial direction of a fluorescent fiber cable 15. Incidence/outgoing of light of plural wavelengths can thus be provided at the same positions.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent fiber cable that can be used for multiple bidirectional communication with a moving body that moves in piping such as a power plant.

[0002]

2. Description of the Related Art As a conventional fluorescent fiber cable, for example, a plastic fluorescent fiber (Japanese Patent Laid-Open No. 2-187) is used.
704) containing one kind of organic fluorescent dye in at least one of the constituent layers of the optical fiber, or an optical fiber and at least one kind of fluorescent light such as a composite optical fiber (Japanese Patent Laid-Open No. 64-40907). Linearly coupled to the fiber,
Depending on the configuration, a plurality of lights having different wavelengths can be propagated, and input / output and selective transmission of light from the side surface are possible.

[0003]

However, the above-mentioned plastic fluorescent fiber can only input and output one kind of signal. Further, the composite optical fiber needs to linearly couple a plurality of fluorescent fibers corresponding to the respective wavelengths at a plurality of points in order to enter and emit light of a plurality of wavelengths from the side surface of the fluorescent fiber. There was an optical transmission loss due to. In addition, signals can be input and output only at the insertion points of the fluorescent fibers corresponding to the respective wavelengths.

[0004]

In order to solve the above problems, the fluorescent fiber cable of the present invention is characterized in that at least one of the core and the clad is mixed with at least two kinds of phosphors and added. It is a thing.

[0005]

The fluorescent fiber cable of the present invention, by virtue of the above-mentioned structure, can enter and emit light of a plurality of wavelengths at any continuous position on the side surface of the fluorescent fiber cable and at the same position. Moreover, it is possible to amplify the optical signals of a plurality of specific wavelengths from the outside by using the light having an appropriate broad spectrum by utilizing the optical amplification effect of the fluorescent substance, and at the same time, by utilizing the condensing / amplifying action of the plurality of optical signals. It can collect and modulate light.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the fluorescent fiber cable of the present invention will be described below with reference to FIGS. Figure 1 is the first
Showing a fluorescent fiber cable (15) which is an embodiment of
(11) shows a core and (12) shows a clad. The core (11) has appropriate condensing / modulating / amplifying functions and has λ1
Phosphor 1 (1 which emits fluorescence of wavelength λ2 by excitation light of
3) and a fluorescent substance 2 (14) which has an appropriate condensing / modulating / amplifying action and emits fluorescence of a wavelength of λ4 by excitation light of λ3 are mixed and uniformly added. Needless to say, the refractive indices of the core (11) and the clad (12) are set so that they can be input / output at the same time as transmitting the excitation lights λ1 and λ2 and the fluorescence λ3 and λ4.

The operation of the fluorescent fiber cable (15) having the above construction will be described below. When the wavelength of the light incident from the end face is different from the absorption wavelengths of the phosphor 1 (13) and the phosphor 2 (14), the light propagates in the core (11) of the optical fiber cable (15), but is incident from the end face. Light is λ1
If it is, it is absorbed by the phosphor 1 (13) and emits the fluorescence of λ2. This λ2 fluorescence is isotropically radiated in the core (11). Of the emitted λ2 fluorescence, if the angle of incidence on the boundary surface between the core (11) and the cladding (12) is larger than the critical angle, it is totally reflected and the core (1
1) The light which propagates in the inside in the axial direction but has an incident angle smaller than the critical angle is radiated to the outside from the side surface of the fluorescent fiber cable (15). Similarly, when the light incident from the end face is λ3, it is absorbed by the phosphor 2 (14) and λ
It emits fluorescence of 4. This λ4 fluorescence is emitted from the core (11).
Inside, it is isotropically radiated. Of the emitted λ4 fluorescence, if the angle of incidence on the boundary surface between the core (11) and the cladding (12) is larger than the critical angle, it is totally reflected and propagates in the core (11) in the axial direction. If the incident angle is smaller than the critical angle, it is radiated to the outside from the side surface of the fluorescent fiber cable (15). This radiation to the outside is continuous at the entire outer circumference of the fluorescent fiber cable (15) in the axial direction. On the other hand, when light is incident from the side surface of the fluorescent fiber cable (15), the wavelength of the incident light is the phosphor 1 (1
3) and the wavelengths λ1 and λ3 which are the wavelengths absorbed by the phosphor 2 (14), respectively.
3) and the fluorescent substance 2 (14) absorbs and wavelength-converts the fluorescence of λ2 and λ4. Of the emitted fluorescent light λ2 and λ4, the light having an angle larger than the critical angle is totally reflected, propagates in the fluorescent fiber cable (15) in the axial direction, and is extracted from the end face. Thus, the phosphor 1 (1) is attached to the core (11) of the fluorescent fiber cable (15).
By mixing and adding 3) and the phosphor 2 (14), it is possible to enter and emit light of a plurality of wavelengths at the same position at any continuous position on the side surface of the fluorescent fiber cable (15). Becomes Moreover, it is possible to amplify the optical signals of a plurality of specific wavelengths from the outside by using the light having an appropriate broad spectrum by utilizing the optical amplification effect of the fluorescent substance, and at the same time, by utilizing the condensing / amplifying action of the plurality of optical signals. It can collect and modulate light.

FIG. 2 shows a fluorescent fiber cable (25) of the second embodiment, in which (21) shows a core and (22) shows a clad. The clad (22) has an appropriate condensing / modulating / amplifying action similar to that described in the first embodiment,
Phosphor 1 (2 that emits fluorescence of wavelength λ2 with excitation light of 1)
3) and a phosphor 2 (24) which has an appropriate condensing / modulating / amplifying action and emits fluorescence of wavelength λ4 by excitation light of λ3 are mixed and uniformly added. Needless to say, the refractive indices of the core (21) and the clad (22) are set so that they can be input / output at the same time as transmitting the excitation lights λ1 and λ2 and the fluorescence λ3 and λ4.

The operation of the fluorescent fiber cable (25) having the above structure will be described below. Light incident from the end face propagates in the core as in a general optical fiber. If the incident angle is smaller than the critical angle at the interface between the core and the clad, it leaks to the clad (22). At this time, when the wavelength of light is different from the absorption wavelengths of the phosphor 1 (23) and the phosphor 2 (24), the light passes through the clad (22) of the fluorescent fiber cable (25) as it is and is emitted to the outside from the side surface. It When the light incident from the end face is λ1, it is absorbed by the phosphor 1 (23) and the fluorescence of λ2 is emitted.
The fluorescence of λ2 is isotropically radiated in the clad (22) and is radiated to the outside from the side surface of the fluorescent fiber cable (25). Similarly, when the light is λ3, it is absorbed by the phosphor 2 (24) and the fluorescence of λ4 is emitted. The fluorescence of λ4 is isotropically radiated in the clad (22) and is radiated to the outside from the side surface of the fluorescent fiber cable (25). On the other hand, when light is incident from the side surface of the fluorescent fiber cable (25), the wavelength of the incident light is the phosphor 1
(23) and phosphor 2 (24) have wavelengths λ1 and λ3 that are absorbed, respectively.
3) and the fluorescence of wavelengths λ2 and λ4 absorbed by the phosphor 2 (24) and converted in wavelength are isotropically radiated in the clad (22). The emitted fluorescence λ2 and λ4 are emitted from the core (2
1) After passing through the inside, the core (21) and the clad (22)
Is totally reflected at the boundary surface of the optical fiber, propagates in the fluorescent fiber cable (25) in the axial direction, and is extracted from the end surface. In this way, by mixing and adding the phosphor 1 (23) and the phosphor 2 (24) to the clad (22) of the fluorescent fiber cable (25), a continuous arbitrary side surface of the fluorescent fiber cable (25) can be obtained. At this position, it becomes possible to enter and emit light of a plurality of wavelengths at the same position. It should be noted that two or more kinds of phosphors having different characteristics may be added to the above-described fluorescent fiber cables (15) and (25) so that two or more kinds of light having different wavelengths can be transmitted and emitted at the same time. . Further, the phosphor does not necessarily need to be uniformly added to both or one or both of the core and the cloughed of the fluorescent fiber cable, may be added non-uniformly, by changing the concentration and mixing ratio to add the phosphor, The emission intensity of fluorescence with respect to light of a plurality of wavelengths may be changed. Further, it is needless to say that each of the plurality of phosphors may have a condensing / modulating / amplifying action characteristic used for its application such as a multiplexer, a demultiplexer, and multiple bidirectional optical transmission. Nor.

FIG. 3 shows an embodiment in which the fluorescent fiber cable of the present invention is used for both-way optical communication. (1 in FIG. 3
5) is the same fluorescent fiber cable as described in the first embodiment, and detailed description thereof will be omitted. (38) is an optical converter (31), a demultiplexer 1 (34), and a demultiplexer 2 (35).
The optical communication device 1 includes a modulator (36) and a demodulator (37). The optical conversion unit (31) converts an electric signal into an optical signal and converts the optical signal into an electric signal, and is composed of, for example, an LED or the like, a light emitting element (32) that generates an excitation optical signal, a phototransistor, and the like. And a light receiving element (33) for receiving a fluorescence signal. The demultiplexer 1 (34) is a filter for selecting, as a light source for exciting the phosphor 1 (13), a wavelength λ1 suitable for the excitation wavelength of the phosphor 1 (13) from a light source having a broad wavelength spectrum, for example. It has a function. The demultiplexer 2 (35) has a filter function of demultiplexing the received optical signal containing noise by wavelength and selecting λ4. The modulator (36) modulates an appropriate information signal and sends the signal to the light emitting element (32). The demodulation section (37) demodulates the signal converted from the optical signal to the electric signal by the light receiving element 1 (33) into the original information signal. Reference numeral (39) is a moving body, which is composed of an appropriate moving mechanism, for example, a moving mechanism (40) that moves by wheel driving, and an optical communication device 2 (41). The optical communication device 2 (41) has the same function and configuration as the optical communication device 1 (38) described above. That is, the demultiplexer 3 (42) and the demultiplexer 4 (43) whose selected wavelengths are λ2 and λ3, respectively, are changed, and other components having the same reference numerals are the same as the constituent elements of the optical communication device 1 (38). However, the description is omitted.

The operation will be described below. First, the transmission of various information will be described. The information signal is the optical communication device 1
It is modulated by the modulator (36) of (38). Next, the modulated electric signal drives the light emitting element (32) of the light conversion section (31), and the light of λ1 selected by the demultiplexer 1 (34) enters from the end face of the fluorescent fiber cable (15). And is propagated in the core (11). Part of the light propagating through the fluorescent fiber cable (15) excites the phosphor 1 (13) in the core (11) and emits fluorescence of λ2, part of which is the side surface of the fluorescent fiber cable (15). Emitted from. The emitted light of λ2 moves to an appropriate position on the side surface of the fluorescent fiber cable (15) and the moving body (39).
By the demultiplexer (42) of the optical communication device 2 (41) having the same configuration, the light of λ2 alone is guided to the light receiving element (33) of the optical conversion unit (31) to convert the optical signal into an electric signal. By being demodulated by the demodulation unit (37), the mobile body (39) can receive the information signal. Next, when the mobile body (39) transmits appropriate information to the optical communication device 1 (38), the information signal is the modulation unit (3).
6) is modulated. Next, the modulated electric signal drives the light emitting element (32) of the light conversion section (31), and the light of λ3 selected by the demultiplexer 4 (43) enters from the side surface of the fluorescent fiber cable (15). And the core (1
The phosphor 2 (14) in 1) is excited to emit the fluorescence of λ4, the fluorescence of λ4 propagates in the core, and is emitted from the end face of the fluorescent fiber cable (15). With respect to the emitted light of λ4, only the light of λ4 is received by the light receiving element (of the light conversion unit 5 (31) by the demultiplexer 2 (35) of the optical communication device 1 (38) located on the end face of the fluorescent fiber cable (15). By being guided to 33), the optical signal is converted into an electric signal, and further demodulated by the demodulation unit of (37), it can be received as an information signal. As a result, the moving body (3) moving various kinds of information through the fluorescent fiber cable (15) as a medium at an appropriate position on the side surface of the fluorescent fiber cable (15).
It is possible to perform bidirectional communication between 9) and an appropriate optical communication device (38) installed on the end face of the fluorescent fiber cable (15).

[0012]

As described in detail above, the fluorescent fiber cable of the present invention can input and output light of a plurality of wavelengths at any continuous position on the side surface of the fluorescent fiber cable and at the same position. Moreover, it is possible to amplify optical signals of a plurality of specific wavelengths from the outside by using light having an appropriate broad spectrum by utilizing the light-enhancing effect of the fluorescent substance, and at the same time, using the condensing / amplifying action of the plurality of optical signals. The light can be condensed and modulated.

[0013]

[Brief description of drawings]

FIG. 1 is an axial sectional view of a first embodiment of a fluorescent fiber cable of the present invention.

FIG. 2 is an axial sectional view of a second embodiment of the fluorescent fiber cable of the present invention.

FIG. 3 is an example of bidirectional optical communication using the fluorescent fiber cable of the first example of the present invention.

[Explanation of symbols]

 11, 21 Core 12, 22 Clad 13, 23 Fluorescent substance 1 14, 24 Fluorescent substance 2 15, 25 Fluorescent fiber cable 31, light conversion part 32, light emitting element 33, light receiving element 34, duplexer 1 35, duplexer 2 36, modulator 37, demodulator 38, optical communication device 1 39, moving body 40, moving mechanism 41, optical communication device 2 42, demultiplexer 3 43, demultiplexer 4

Front page continued (72) Inventor Hiroshi Okamoto 2-3-1, Sakae, Naka-ku, Nagoya-shi, Aichi

Claims (1)

[Claims] 1. At least one of a core and a clad,
Fluorescent fiber cable characterized in that at least two kinds of phosphors are mixed and added