Filters and mounts
136
Goldeye G/CL Technical Manual V4.1.1
Specific filter applications
Bandpass filter
The Goldeye responds to wavelengths from about 900 nm to 1700 nm. It is
possible, however, to restrict the complete bandwidth to a certain range of
wavelengths by using a corresponding bandpass filter. That way, only a certain
wavelength band is transmitted, all others are blocked.
The describing characteristics of a bandpass filter are properties like optical
density, or spectral profile. The main characteristics, however, are the center
wavelength (CWL) together with the bandwidth (full width at half maximum,
FWHM) being transmitted.
For example, the CWL of a water filter displayed in Figure 39 is 1450 nm with a
tolerance of ±7 nm, and FWHM bandwidth of 26.5 nm.
Bandpass filters 1450 nm (water filters)
Readily assembled mount adapters with filter glass for several lens mounts are
available for purchase from Allied Vision.
Figure 39: Example of a water filter: CWL = 1450 nm
±7 nm, FWHM = 26.5 nm
0.01
0.1
1
10
100
1370
Wavelength [nm]
Transmission [%]
1390
1410
1430
1450
1470
1490
1510
1530
~40%
~80%
HW = 26.5 nm
1
