The Single Cavity Filter (SCF) is used to select a single frequency from a broad spectral range. SCFs are typically used for wavelength locking.
Center Wavelength (CWL) [nm]:
The center wavelength (CWL) is defined as the mean wavelength @ -3 dB of the SCF e.g.
If the –3 dB bandwidth of the SCF is 1564.825 – 1565.175 nm then the CWL is (1565.175 + 1564.825)/2 ~ 1565.000 nm.
Band Width (BW) [nm]:
The width of the transmittance curve about the center wavelength at a certain specified transmittance level.