Infrared Light Source for the SFA

Description

Researchers sometimes need an infrared light source for non-intrusive observation of behavior. And sometimes the subjects are small and you need to make the observations with a stereo microscope. The SFA-LH-IR850 (Figure 1) is an 850nm light source that is compatible with the NIGHTSEA Model SFA Stereo Microscope Fluorescence Adapter. The light head plugs directly into the lamp base supplied with the SFA system (Figure 2). You can acquire the light head as a supplement to the SFA system that you already own for fluorescence observation, or you can acquire it in combination with a lamp base as a stand-alone device.

Figure 1. 850nm IR Light Head	Figure 2. 850nm IR Light Head on SFA lamp base

  The light head incorporates a high power 850nm LED and a medium beamwidth diffusing lens to create a smooth illumination area. The output is centered at 850nm with a FWHM (full width at half maximum) of approximately 50nm. There is virtually no emission at wavelengths shorter than 750nm. Figure 3 below shows a test target with circles of 2, 5, and 10cm diameter. This photograph was taken with a conventional camera under normal room light, and with the IR light head illuminated at full power, directed at the target center from a distance of approximately 10cm (4 in.). The illumination spot is not visible either to this camera or to the naked eye. Figure 4 is a photograph made under the same lighting conditions, but with a camera that had been modified to image only infrared light. We recommend that you use the DIM base with the LH-IR850 in order to have finer control of illumination intensity.

Figure 3. Test target for IR Light Head, room light	Figure 4. Test target for IR Light Head, Infrared

  Note that infrared light is not visible to the human eye and to many cameras. You will need an appropriate camera to record the observations.