Optical bandpass filters are designed to transmit a specific waveband.  They are composed of many thin layers of dielectric materials, which have differing refractive indices to produce constructive and destructive interference in the transmitted light

Active band pass filters are used to attenuate frequencies below and above a range of frequencies (i.e., the bandwidth or passband of the filter

Active filters are electronic filers that use active components such as voltage amplifiers or operational amplifiers. The amplifier shapes and stabilizes the behavior of the filter, and serves as a buffer interface to the driven component

RF filters and microwave filters are devices that pass or reject signals by frequency. Basic types include bandpass filters, band reject filters, low pass filters, and high pass filters

IC electronic filters are frequency-selective circuits that consist of devices such resistors, capacitors, inductors, transistors, or operational amplifiers coupled with reactive components

RF band pass filters are active or passive circuits that pass signals from a specific frequency band and reject signals from out-of-band frequencies. Surface acoustic wave (SAW) filters, crystal filters, and cavity filters are types of band pass filters

Interferometers measure distance in terms of wavelength and determine the wavelengths of light sources.

Active low pass filters pass signals from low frequencies and reject signals from high frequencies

Filtration media and elements are designed to remove suspended particles from a process stream. This product area includes bulk filter media, cartridges, housing-only products, and housing and filter assemblies. 

Electromagnetic (EMI) filters and radio frequency interference (RFI) filters purify signals by attenuating the high-frequency RFI (typically 150kHz and up) and passing the low frequency EMI

Active band reject filters are tuned circuits that prevent the passage of signals within a specified band of frequencies. These devices are also known as bandstop or notch filters

Active high pass filters pass signals from high frequencies and reject signals from low frequencies

Industrial air filters reduce the number of particles in the air that passes through them. 

Signal filters block or decrease (attenuate) unwanted frequencies or signal wave characteristics

Industrial filtration equipment is used to filter, thicken or clarify a mixture of different elements