PROGRAMMABLE ULTRAVIOLET ILLUMINATOR USING AN AOTF

INCREASING USE OF FURA-2 AND OTHER DUAL EXCITATION PROBES HAVE HIGHLIGHTED THE ADVANTAGES OF THE RATIO METHOD FOR DETERMINING INTRACELLULAR ION CONCENTRATIONS. THIS HAS FOSTERED THE DEVELOPMENT OF NEW PROBES (E. G., FOR NA+, K+, H+, AND MG2+) WITH WHICH ION CONCENTRATIONS ARE DETERMINED AS A FUNCTION OF THE RATIO OF THE FLUORESCENCE EMISSION EXCITED BY ILLUMINATION AT TWO WAVELENGTHS (DUAL EXCITATION). UNFORTUNATELY, THE DEVELOPMENT OF RELATIVELY INEXPENSIVE ULTRAVIOLET (UV) AND VISIBLE FLUORESCENCE ILLUMINATION SYSTEMS FOR USE WITH THESE PROBES LAGS BEHIND THE DEVELOPMENT OF THE PROBES THEMSELVES. THIS IS ESPECIALLY TRUE WHEN THE PROBES ARE USED FOR DIGITAL IMAGING, WHERE EXCITATORY ILLUMINATION MUST BE GATED SYNCHRONOUSLY WITH THE VIDEO FRAMES. TO ADDRESS THIS PROBLEM, AN OPTIMIZED ACOUSTO-OPTIC TUNABLE FILTER (AOTF) WILL BE FABRICATED AND INCORPORATED INTO A NEW ULTRAVIOLET AND VISIBLE ILLUMINATOR FOR DUAL EXCITATION PROBES. THE ILLUMINATOR WILL BE DEMONSTRATED IN A FLUORESCENCE MICROSCOPY APPLICATION, WHERE THE USE OF AOTF TECHNOLOGY WILL PERMIT FAST AND ACCURATE CONTROL THE WAVELENGTH, TIMING AND INTENSITY OF THE EXCITATION. THE DESIGN OF THE AOTF AND ILLUMINATOR WILL MAXIMIZE THE FILTERED OPTICAL POWER IN THE 330 TO 350 NM RANGE FOR USE WITH FURA-2 AND OTHER DUAL EXCITATION PROBES.