Parameter
Definition |
Example |
Wavelength Tuning Range (nm) is the spectral range over which a ROADM's center wavelength can be
tuned and performance specification can be met.. |
1527.994 ~ 1563.047 nm |
Wavelength
Tuning Resolution (GHz) is the minimum
tuning step of a tunable filter. |
10 pm |
Passband Width @ X-dB Down (GHz) is the full spectral width centered
at the ITU grid measured at X-dB below the minimum insertion loss
point. Usually, X = 0.5, 1, 3 and 20. |
35 GHz @0.5-dB down for 100 GHz channel spacing |
Peak
Insertion Loss (dB) is power
difference between the 0-dB level and the maximum power level measured within
a given passband window. |
2.5 dB |
Polarization
Dependent Loss (PDL) (dB) is the difference
between the maximum and minimum insertion loss over all polarization states
within a given passband window. |
0.3 dB within CW ± 12 GHz |
Polarization
Mode Dispersion (PMD) (ps)
is the maximum Differential Group Delay within a given passband width. |
0.3 ps |
Chromatic
Dispersion (CD) (ps/nm)
is the derivative of the Group Delay versus wavelength within a given passband width. |
± 25 ps/nm within CW ± 12 GHz |
Wavelength
Setting Error (GHz) is the difference between a
channel central wavelength (usually defined using 3-dB bandwidth) and the
target wavelength (usually the ITU grid) during tuning. |
± 4 GHz |
Wavelength
Repeatability (GHz) is the repeatability of a
channel central wavelength (usually defined using 3-dB bandwidth) during
repeated tuning. |
± 1 GHz |
Wavelength
Temperature Dependence (pm/°C) is the rate of a
channel central wavelength versus temperature. |
± 1
pm/°C |
Optical
Return Loss (dB) is the ratio between the input
power and the reflected power over all polarization states at each port , RL = -10×log10(Pr/Pin). |
40 dB |
Tuning
Speed (s) is the time needed by a tunable filter
to tune from one channel to another. It is dependent on the originating and
destination channels. The longest time required is specified. |
6 s |
Operating
Temperature (°C) is the ambient temperature
range over which the device's performance spec can be met. |
-5 to 65 °C |
Storage
Temperature (°C) is the ambient temperature
range over which the device can be stored without affecting its intended
application afterwards. |
-40 to 85 °C |
