The following filters are currently available in LWS. See below for plots of filter transmission curves compared to the atmospheric transmission measured for Mauna Kea.
Name Bandpass¹ [µm] Bandpass 2 Data 
L 3.5-4.2 N/A N/A
M 4.4-5.0 N/A N/A
8.0 7.81-8.94 plot table
8.9 8.39-9.27 plot table
9.9 9.67-10.42 plot table
10.7 9.92-11.47 plot table
SiC 10.64-12.96 plot table
11.7 11.15-12.25 plot table
12.5 12.01-13.25 plot table
17.65  17.31-18.16 plot table
18.75 18.31-19.20 plot table
23.1 22.74 - 23.47 plot table
24.5 24.16 - 24.90 plot table
Nwide3 7.73-13.31 plot table
Spec 10 >7.52 µm (long pass) plot table
Spec 20 >13.93 µm (long pass) plot table


  1. Wavelength range over which filter transmission exceeds 50% of peak.
  2. The transmission data and wavelength calibration are in agreement with manufacture's data.
  3. Nwide cannot be used for imaging. The 5 micron bandwidth results in excessive background levels and saturates the detector. The SiC filter is better suited for broad band imaging with LWS. Nwide is used as a blocking filter for spectroscopy.

Filter transmission over the 10 and 20 micron atmospheric windows.

The atmospheric trasmission spectra are calculated by Lord, S. 1992, NASA Tech. Mem. 103957. The filter transmission curves are taken from the table above.
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