Optics: measuring and testing – Refraction testing – Prism engaging specimen
Patent
1993-12-30
1996-04-09
McGraw, Vincent P.
Optics: measuring and testing
Refraction testing
Prism engaging specimen
G01N 2184
Patent
active
055066747
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention relates to a method for identifying an optical line at one end thereof which is used in optical communication system.
BACKGROUND ART
A method for identifying an optical line by varying a refractive index of an optical line core in part, and detecting a position of the varied refractive index part at one end of the optical line using the OTDR method has been known ("Remote Fiber Discrimination Method for an Optical Transmission Line Database", 1991, DENSI JYOUHOU TSUSIN GAKKAI SHUKI TAIKAI, Reference B-591).
However, according to this method, an identification code composed of the varied refractive index parts on the optical line extends over hundreds meters. For instance, in an example of the reference described above, to record a 8 bits identification code on the optical line requires a 50m for a bit and a total of 400m. Accordingly, it is difficult to apply the identification code to a short optical line. Recording the identification code extending over hundreds meters on the optical line has to be done during a manufacturing process of the optical line, which is not practical.
DISCLOSURE OF THE INVENTION
An object of this invention is to provide a method for identifying an optical line easily and accurately regardless of the optical line length.
In order to achieve the object, a first method of the present invention comprises the steps of: identification code, the each optical line having a specific combination of relative positions of the reflecting parts; lights when a detecting light is inputted to the optical line; and
When the detecting light is inputted to one end of the optical line, the light is reflected at the plurality of the reflecting parts, and comes back to the input end. A combination of the relative positions of the reflecting parts is changed for every optical line. To detect the relative positions of the reflecting parts forming an identification code, either the optical path difference of the reflected lights is measured with the interferometer or the time difference between the reflected lights coming back from the reflecting parts is measured, so that the optical line can be identified based on the result.
A second method of the present invention comprises the steps of: identification code, the each reflecting part reflecting a light having a specific wavelength, and the each optical line having a specific combination of the specific reflecting wavelengths; inputted to optical line; and
When the detecting light is inputted to one end of the optical line, the light is reflected at the reflecting parts which form an identification code and comes back to the input end. As a combination of the wavelengths of the reflected lights at the reflecting parts is changed for every optical line, the wavelengths of the reflected lights are measured, so that the optical line can be identified based on the result.
A third method of the present invention comprises the steps of: identification code, the each reflecting part reflecting a light having a specific wavelength, and the each optical line having a specific combination of the specific reflecting wavelengths and reflectances; detecting light is inputted to optical line; and
When the detecting light is inputted to one end of the optical line, the light is reflected at the reflecting parts which form an identification code and comes back to the input end. As a combination of the wavelengths and reflectances of the reflecting parts is changed for every optical line, the wavelengths and the light intensities of the reflected lights are measured, and based on the result, the optical line can be identified.
A fourth method of the present invention comprises the steps of: the reflecting part on the each optical line having a specific reflectance characteristic depending on a wavelength; detecting light is inputted to the optical line; and
When the detecting light is inputted to one end of the optical line, the light is reflected at the reflecting parts which form an identification code and comes back to the inpu
REFERENCES:
patent: 5187546 (1993-02-01), Johnston
Patent Abstracts of Japan, vol. 16, No. 308 (P-1381) Jul. 7, 1992 & JP-A-04 084 727 (NTT) Mar. 18, 1992.
Patent Abstracts of Japan, vol. 14, No. 452 (P-1112) Sep. 27, 1990 & JP-A-02 181 101 (Fujikura) Jul. 13, 1990.
Arakawa et al., "Optical Fiber Identifier for Dispersion-Shifted Fiber Cables", NTT Review, vol. 4, No. 2, Mar. 1992, pp. 53-56.
Hattori Yasuji
Inoue Akira
Katsuyama Yutaka
Ohtsuki Fumio
Yamashita Katsuya
McGraw Vincent P.
Nippon Telegraph & Telephone Corporation
Sumitomo Electric Industries Ltd.
LandOfFree
Method for identifying an optical fiber using a pattern of refle does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for identifying an optical fiber using a pattern of refle, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for identifying an optical fiber using a pattern of refle will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-142492