Related Experiment Video
Updated: Jun 8, 2026

Fabrication of a Low-Cost, Fiber-Coupled, and Air-Spaced Fabry-Pérot Etalon
Published on: February 3, 2023
Far-infrared bandpass filters from perforated metal screens
Abstract:
Precision nickel printing screens are shown to be very useful as far-infrared bandpass filters. For a range of such regularly perforated sheets, transmission peaks of ~ 0.9 have been observed to lie at frequencies between 60 and 140 cm(-1). We found that this value shows little degradation by cascading several screens, but the overall filter Q value may be increased from 2.7 to a value of ~ 6. These screens have considerable advantages over conventional far-infrared bandpass filters in terms of strength, optical characteristics, and cost.
Related Concept Videos
Passive Filters
Low-Pass Filters
Low-pass filters are designed to transmit signals with frequencies lower than the cutoff frequency, ωc, and attenuate those above it. The cutoff frequency...
Active Filters
IR Spectrometers
IR Spectrum
Transmittance is defined as the ratio of the radiant power passing through a sample to that from the radiation's source. Multiplying the transmittance by 100 gives the percent transmittance (%T), which varies between 100% (no absorption) and 0% (complete...
Bandpass Sampling
A bandpass signal has a spectrum with a lower frequency limit, denoted as ω1, and an upper frequency limit, denoted as ω2. The spectrum...
IR Frequency Region: Fingerprint Region
The...

