Narrow Bandpass
Overview
Narrow bandpass filters are designed to isolate a narrow region of the infra-red spectrum. This is accomplished using a complex process of constructive and destructive interference. Narrow band pass filters have bandwidths (measured at half-peak transmittance levels) less than 6% of the centre of wavelength value. When ordering, the bandwidth can be expressed as a percentage of the centre wavelength, or can be given in microns. The filters exhibit high peak transmission (typically greater than 70%) combined with high attenuation levels outside the passband (typically less than 0.1%).
Typical Characteristics
| Available wavelength range | ~1.2 to 20 µm |
| Tolerance on CWL | To customers requirements, but standard tolerances are typically ±0.3% for a 1% bandwidth filter to ±1% for a 6% bandwidth filter |
| Peak transmittance | Typically >70% (depending on wavelength and bandwidth) |
| Available bandwidths | Typically 0.9% to 6% |
| Blocking (attenuation) | Typically <0.1 % from 0.3 micron to far infrared |
Typical Performance
