IEC 61290-6-1:1998 pdf download – ptical fibre amplifiers -Basic specification -Part 6-1: Test methods for pump leakage parameters -ptical demultiplexer

IEC 61290-6-1:1998 pdf download – ptical fibre amplifiers -Basic specification -Part 6-1: Test methods for pump leakage parameters -ptical demultiplexer.
This part of IEC 61290 applies to optical fibre amplifiers (OFAs) using active fibres, containing rare-earth dopants, presently commercially available.
The object of this standard is to establish uniform requirements for accurate and reliable measurements, by means of the optical demultiplexer test method, of the following OFA parameters, as defined in clause 3 of IEC 61291-1
a) pump leakage to output;
b) pump leakage to Input.
NOTE — All flunlerical valuee loilowed by (tI are Ct%re4llIy under coneideration.
2 Normative reference
The following normative document contains provisons which, through reference In this text. constitute provisions of this part of lEG 61290. At the lime of publication, the edition indicated was valid. All normative documents are subject to revision, and parlies to agreements based on this part of IEC 61290 are encouraged to investigate the possibility of applying the most recent edition of the normative document indicated below. Members of IEC and ISO maintain registers of currently valid International Standards.
IEC 61291-1. — Optical fibre amplifiers — Part 1: Generic specification 11
3 Apparatus
A scheme of the measurement set-up is given in figure 1.
b) optical isolator.’ The polarization-dependent loss variation of the isolator shall be belier than 0.2 dB (t). Ophcal isolation shall be better than 40 dB (t). The reflectance from this device shall be smaller than —40 dB (t) at each port;
C) variable optical attenuator: It shall be insensitive to polarization, and its attenuation range and stability shall be over 40 dB (t) and better than ±0,1 dB f), respectively, The reflectance from this device shall be smaller than —40 dB () at each port;
d) optical demultiplexer.’ The polarization dependence of the optical demultiptexer transmissivity shall be less than ±0,1 dB (t). This device shall have the following characteristics:
— the port A shall have a passband at the pump and the signal wavelength ranges, it shall be internally connected to ports B and C;
— the port B shall have a passband at the pump wavelength range, and with a loss higher than 20 dB () at the signal wavelength range (this ensures that also the amplified spontaneous emiseFon Is blocked by this port);
— the port C shall have a bandpass at the signal wavelength range and with a loss higher than 20 dB () at the pump wavelength range:
— the reflectance from port A shall be lower than —50 dB ():
C) optical power meter: It shall have a measurement accuracy better than ±0,2 dB, irrespective of the state of polarization, within the signal and the pump wavelength ranges of the OFA;
I) optical fibre jumpers; The mode field diameter of the optical fibre jumpers used should be as close as possible to that of fibres used as input and output ports of the OFA, Their reflectance shall be smaller than —40 dB (*) at each port, and the length of each jumper shall be less than 2 m.
4 Test sample
The OFA shall operate at nominal operating conditions. Care shall be taken in maintaining the state of polarization of the input light during the measurement. Changes in the polarization state of the input light may result In input optical power changes because of the slight polarization dependency expected from all the optical components used, these leading to measurement errors.
5 Procedure
This method permits determination of both the pump leakage to output and to input through the measurement of the pump power exiting the OFA, measured alter an optical demultiplexer, and discriminated from the signal power by means of an optical demultiplexer. whose inserlion loss shall be previously determined.
The measurement procedures described below shall be followed:
a) pump leakage to output
1) In order to evaluate the optical demultiplexer insertion loss, set the optical source, as shown in figure 2, at the pump wavelength, as specified in the relevant detail specification,
2) Measure the optical power, PB. at the optical demultiplexer output port B, with an optical power motor as shown in figure 2. having terminated port C.
3) Measure the optical power, A. at the optical demultiplexer input port A, as shown in figure 2, but replacing the optical demultiplexer with the optical power meter.