JPH0546144U - Optical communication system - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an optical communication system for both temperature sensor and data transmission. [Configuration] is incident pulsed light 2 having a wavelength of incident ₁ to the optical fiber 1 from the pulse drive circuit 7 and the laser diode 8 in the temperature measuring body 6 is a temperature sensor, avalanche backscattered light 5 coming back photo da The temperature is calculated from the dependency on the temperature received by the data processor 10 and the Eid 9. An optical demultiplexer 11 is connected in the middle of the optical fiber 1, and an optical transmission device 12 is connected via these optical demultiplexers 11. Optical communication for other purposes can be performed between the optical transmission devices 12 by using an optical signal with wavelength ₂ which does not affect the temperature sensor. This optical communication can be applied to various communication systems currently used such as data, video and audio.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an optical communication system in which an optical fiber for temperature sensor is also used for communication.

[0002]

[Prior Art]

 Conventionally, optical fibers have been mainly used for communication, but in recent years, techniques for applying optical fibers as temperature sensors have advanced. The technique of using an optical fiber as a temperature sensor is known, and its principle is shown in FIG.

When the laser pulse light 2 is incident on the optical fiber 1, the position where the scattered light 3 is generated can be grasped by the delay time until the back scattered light 5 returns to the incident end again. Although Raman contained in this scattered light is weaker than Rayleigh scattered light, it is known that the intensity depends on temperature. The temperature of the scattered light generation point can be obtained from the intensity of the Raman scattered light returning to the incident end.

On the other hand, recently, as an optical fiber for communication, it is most commonly used and is used as a transmission medium for various data, video and audio signals. Absent.

[0005]

[Problems to be solved by the device]

 In the conventional technology, it is necessary to install separate optical fibers for data transmission and temperature sensor, which complicates the system and makes the construction difficult.

An object of the present invention is to solve the above-mentioned drawbacks of the prior art and provide an optical communication system in which a temperature sensor and a data transmission are shared.

[0007]

Means and Actions for Solving the Problem The gist of the present invention is that it is applied as a communication system so that various data transmissions can be performed by using an optical fiber used for a temperature sensor.

That is, the above object of the present invention is to connect an optical demultiplexer to an optical fiber cable for a temperature sensor of an optical fiber type temperature measuring device, and to connect an optical transmission device for communication to the optical demultiplexer. Optical communication system characterized by

[0009]

【Example】

 An embodiment of the system configuration of the present invention is shown in FIG.

[0010] is incident from the pulse drive circuit 7 and Rezadaio over de 8 in temperature measuring body 6 pulsed light 2 having a wavelength of incident ₁ to the optical fiber 1 as a temperature sensor, the backscatter light 5 coming back avalanche It is received by the photodiode 9 and the data processing circuit 10, and the temperature is calculated from the dependence on the temperature. An optical demultiplexer 11 is connected in the middle of the optical fiber 1, and an optical transmission device 12 is connected via these optical demultiplexers 11. Optical transmission for another purpose can be performed between the optical transmission devices 12 by using an optical signal with wavelength ₂ that does not affect the temperature sensor. This optical communication can be applied to various currently used communication systems such as data, video and audio.

[0011]

[Effect of the device]

 With the optical communication system of the present invention, it is possible to unify the optical fibers conventionally constructed for different purposes and to effectively utilize the transmission line. This will reduce material costs and construction costs.

[Brief description of drawings]

FIG. 1 is a system diagram showing an embodiment of an optical communication system using an optical fiber for a temperature sensor of an optical fiber type temperature measuring device of the present invention.

FIG. 2 is an explanatory diagram showing the principle of an optical fiber temperature measuring device.

[Explanation of symbols]

 1 optical fiber for temperature sensor 2 laser pulsed light 3 scattered light 4 transmitted pulsed light 5 backscattered light 6 temperature measuring instrument body 7 pulse drive circuit 8 laser diode 9 avalanche photodiode 10 data processing circuit 11 optical demultiplexer 12 optical transmission device

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical indication location G02B 6/00 H04J 14/00 14/04 14/06 9017-2K G02B 6/00 C 8426-5K H04B 9/00 F

Claims (1)

[Scope of utility model registration request] 1. An optical communication device, wherein an optical demultiplexer is connected to an optical fiber cable for a temperature sensor of an optical fiber type temperature measuring device, and an optical transmission device for communication is connected to the optical demultiplexer. system.