SU1300306A1 - Device for measuring attenuation of optical cables - Google Patents

Abstract

The invention relates to electrical measuring equipment and can be used to measure the attenuation of optical cables during their manufacture, installation and use. The invention makes it possible to significantly improve the accuracy of the attenuation measurement near the Fresnel reflection signals. Accuracy improvement is achieved by compensating for the Fresnel reflection signals by introducing an adjustable delay unit 8, a second optical signal source 9, an adjustable optical attenuator 10, and a second photodiode 1 1 and creating an auxiliary electro-optical channel on their basis. 1 il. I l: o o: o o 3

Description

The invention relates to electrical measuring equipment and can be used to measure the attenuation of optical cables (OC) during their manufacture, installation and operation.

The purpose of the invention is to improve the accuracy of the attenuation measurement,.

The drawing shows a block diagram of the device.

The device contains sequentially connected master oscillator 1, source 2, optical signals (IOS) whose output is connected to the first arm of the directional coupler 3, the second arm of which is connected to the input of the OK test 4, the third arm of the directional coupler 3 is connected via a photodiode 5 and an amplifier 6 sec the input of the recording device (RU) 7, the synchronization input of which is connected to the output of the master oscillator 1j serially connected adjustable block 8 delay (RBZ), an additional source 9 of optical signals, re uliruemy optical atm tenyua.tor (ROA) and 10 additional photodiode 11, the ERB input 8 connected to the output of the master oscillator

1, and the output of the additional photodiode

11 Is connected to the input of the amplifier 6 differentially relative to the main photodiode 5.

The device works as follows.

The attenuation measurement is performed in three stages: first, the Fresnel irradiation signal (SFO) is searched for by a known device, and the time interval to the SFO and its value is determined using the RF;

At the second stage, the SFR is compensated, with the help of additional IOS and ROA, a compensating pulse is formed and the necessary delay time is turned on.

To measure the attenuation of the OK from the output of the master oscillator 1, electrical pulses are fed to the input of the IOS

2, are converted into electrical ones and through the first-second arm of the directional coupler 3 are fed into OK 4, SFO and backscatter signals (COP) through the third and second arm of the directional coupler arrive at the photodiode 5, where optical; signals

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they are converted into electric ones, and then amplified in amplifier 6 and prepared for recording device 7.

Then, a time delay is formed using the RBZ 8 and the amplitude of the compensating pulse using XRD 10. Through the serially connected RBZ 8, additional OIC 9, POA 10 and additional, photodiode 11 compensating signals are fed to the input of the amplifier 6 where the SFO compensation occurs.

Thus, the introduction of an adjustable delay unit, a radiation source, an adjustable optical attenuator and a photodiode can significantly improve the accuracy of measuring the attenuation of an optical cable in the vicinity of large inhomogeneities distributed along the length of the line.

Claims (1)

Invention Formula An apparatus for measuring the attenuation of optical cables, comprising a series-connected master oscillator, an optical signal source,. optically coupled to the first arm of the directional coupler, the second arm of which is optically connected to the input of the optical cable under test, and its third arm is optically connected to the photodiode, the output of which through the amplifier is connected to the input of the registering device, the synchronization input of which is connected to the output of the master oscillator, About the fact that, in order to improve accuracy: attenuation measurements, an adjustable delay unit is introduced into the hero: both an optical attenuator, an additional photodiode and an optical source ignalov optically bonded via adjustment Optical: s with additional photodiode attenuator, wherein the input unit delay controlled sub khpochen to the output of the master oscillator, and an output - to an additional source of optical signals, an additional photodiode is coupled to the input of amplifier differentsialno relative to the main photodiode. Subscription