Fluorescence is widely used to detect the biochemical effect and some substance containing certain dye. In general, the formation of fluorescent reaction is that an organism or dye, excited by UV light, emits a specific frequency of light; the light is usually a visible or near infrared light. Practically, the fluorescence of object can be excited by continued UV light, but the contrast and sharpness of fluorescence image decrease readily with stray light from the surrounding. In this study, we connect a trigger LED light module to a portable camera system and to perform the fluorescence inspection. When the fluorescent object is excited by asynchronous trigger UV-LED light, the extra intensity of fluorescence can be obtained. In the experiment of security organic dye (BL-ORT), the relative intensity of fluorescence acquired by 30 fps CCD can be increased by more than 11 %. In addition, when the fluorescent dye (chlorine e6) is injected into the tail vein of nude mouse, if its tail excited by the 375nm asynchronous trigger and continuous UV-LED are processed, the average relative intensity is 56.5 % and 49 %, respectively. Therefore, an added relative fluorescence of 15.3 % can be obtained from asynchronous triggering method. Furthermore, the ratio of extra intensity increases with the increase of frame rate of camera.
Near infrared throughput and stray light measurements of diffraction gratings for ELT-HARMONI