Parameter Definition

Example

Wavelength Tuning Range (nm) is the spectral range over which a tunable optical filter'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