A filter with a single transmission band extending from lower to upper cutoff frequencies. The width of the band is normally determined by the separation of frequencies at which amplitude is attenuated by 3 dB (a factor 0.707 ).
A band-pass filter only transmits light components with a specified wavelength. The band-pass filter incorporated into the VG Series receiver has a characteristic that only passes light components with the wavelength of the semiconductor laser used in the VG.
A band-pass filter is a device that passes frequencies within a certain range and rejects (attenuates) frequencies outside that range. An example of an analogue electronic band-pass filter is an RLC circuit (a resistor-inductor-capacitor circuit). These filters can also be created by combining a low-pass filter with a high-pass filter.