專業Narrow Bandpass Filters廠商

H-alpha, H-beta, OIII, SII or Stroemgren u, v, b, y...
Astronomical narrow bandpass filters are necessary for most of telescopes and play the important role of the scientific advances.

Generally it is harder to fabricate the narrow bandpass filter, because the minimal error for film design is required to form the narrow passband, especially narrower e.g. 5nm FWHM.
Furthermore, smaller tolerance for CWL or FWHM is often required than broad bandpass.
It means it is the key technology to keep the good uniformity over the clear aperture when the large format narrow bandpass filter is requested.

Asahi has achieved large format (diagonal line: approximate 300mm) H-alpha filters with good uniformity and monolithic substrate. They will be installed in Palomar Transient Factory wide-field survey camera.

Our goal is that we will be able to supply over 600mm narrow bandpass filter for Dark Energy Survey (DECam), WIYN Observatory (ODI) or Subaru Telescope (HSC).