Properties of the N662 filter
The N662 is a narrow band filter centered at 6622.4 Angstroms with a FWHM of 170 Angstroms. The filter covers the redshifted Halpha+[NII] emission in the radial velocity range from -1200 km/s to 6000 km/s. The filter was made by Asahi Spectra in Japan and funded by an international team with P.I.s Eric Peng (Peking University, China) and Thomas Puzia (PUC, Chile). Filter N662 is available for use by the NOIRLab and Chilean communities under the same conditions as the PIs and their team, with prior authorization on a project by project basis by both PIs. Please contact us in advance if you are interested in using this filter.
The following plot shows the transmission curves over the filter as measured by the manufacturer on 3 different locations: