IEC TR 61292-1 pdf download – Optical amplifiers – Part 1: Parameters of amplifier components

IEC TR 61292-1 pdf download – Optical amplifiers – Part 1: Parameters of amplifier components
1) The positive difference of the closest spaced wavelengths,one above and one below
the peak wavelength -peak， at which the spectral power density is 3 dB down from itspeak value.
2) The difference of the half-power wavelengths can be determined as follows; since the
laser may not have modes at these wavelengths, they may be obtained by interpolation.3) Connect the tip of each mode to the tips of adjacent modes; draw a horizontal line 3-dBdown from the peak power point.
4)The two or more intersection points define the half-power wavelengths. The maximum
difference in half-power wavelengths is Awhm-
NOTE Refer to EC 61280-1-3 for details.
5.2.6
wavelength stability
rate of variation of pumping wavelength with respect to operating and environmental conditions
5.2.7
threshold current
driving current at which the pump laser starts to lase.Practically, this value is specified as thecrossing condition between the spontaneous emission and lasing regions
5.2.8
maximum allowed current
maximum driving current which may cause irreversible damage to the pump laser. A current,derated from the absolute maximum rating. is generally applied
5.2.9
pump LD chip temperature
temperature of chip to be controlled for normal operation,where performance of pump LDensured
NOTE The output power and operating wavelength are affected by laser chip temperature. Therefore ordinarypump LD module includes a TEC in order to maintain LD chip temperature.The temperature range of 25 c~ 45c
chlips are specified to operate at 35C or 45“C.
is commonly specified by LD vendors. Previous generation chips are specified at 25 “C, and some more recent
5.2.10
pump LD case temperature
operative temperature range of LD case within which the pump laser module can be operatedwhile still meeting all its specified parameter values, given in the relevant detail specification
NOTE Power consumption of temperature controlled pump LD module with TEC features differs for various casetemperatures since TEC is operated to maintain LD chip temperature against various (high or low) temperatures。The case temperature also affects center wavelength and wavelength stability of pump laser with FBG wavelengthstabilizer， since reflection wavelength of FBG is varied for its case temperature， Therefore pump LD case
module is specified for case temperature range around 0C~75“℃.
temperature is specified by LD vender to ensure normal operation of all the related performance.Most of LD
5.2.11
chip temperature dependence of threshold current
threshold current dependence on pump laser chip temperature
5.2.12
case temperature dependence of wavelength
wavelength dependence of the center wavelength of the laser on the pump laser casetemperature, expressed in nm/c
5.2.13
device reliability
probability of performing required functions at specified operating and environmental conditions.The reliability of a pump laser is expressed by either of the following two parameters: meantime between failure (MTBF) or failure in time (FIT):
MTBF is the mean period of continuous operation without any failure at specifiedoperating and environmental conditions
FIT is the number of failures expected in 109 device-hours at specified operating andenvironmental conditions
5.3WDM coupler
A WDM coupler is used to unify pump light with signal light and to guide combined light toactive fibre. Thin film technology or tapered fused coupler technology is commonly applied tothe wDM coupler.
5.3.1
wDM coupler signal insertion loss
fraction of the optical power associated with the input signal and launched into the signal inputport of the coupier which does not exit from the signal output port of the coupler,expressed indB
5.3.2
wDM coupler pump insertion loss
fraction of the optical power associated with the pump and launched into the pump input port ofthe coupler which does not exit from the signal output port of the coupler, expressed in dB
5.3.3
wDM coupler PDL
maximum insertion loss variation due to the change of the input light state of polarization,expressed in dB.This term is defined for both signal input port and pump input port
5.3.4
wDM coupler signal reflectance
fraction of the optical power associated with the input signal which is reflected by the signalfrom input port of the coupler, expressed in dB
5.3.5
wDM coupler PMD
maximum ‘PMD at the signal wavelength which is launched into the input port of the couplerand exits from signal output port of the coupler, expressed in ps (picosecond)
5.3.6
pump leakage at the signal input port
fraction of the optical power associated with the pump injected into the coupler which exitsfrom the signal input port, expressed in dB