Real-time, near-infrared fluorescence imaging system

An infrared camera captures images of objects that emit radiation in the infrared region of the electromagnetic spectrum. In this study, a fluorescence imaging system involving a specifically designed infrared camera was developed. CCDs can detect infrared light in the invisible region of the electromagnetic spectrum (>780 nm); however, a low-pass filter is installed in front of the CCD to filter out most infrared light and prevent the light from affecting the quality of color photos. Although an ordinary camera can take infrared photos when an infrared filter is installed to its lens, a modified camera is impractical because the amount of infrared light entering the CCD is limited, resulting in the requirement of a longer exposure time. Therefore, the principle of modifying a high-speed infrared camera is to remove the low-pass filter and adopt an ordinary shutter speed to take infrared photos.