AOTF | AOTF
Key Words: photobleaching, phototoxicity, lasers, fluorescence, live cell imaging, FRAP, FLIP, PA-GFP, AOM, time-lapse
Definition:An AOTF is a solid-state, electronically tunable bandpass filter
An AOTF is similar to an AOM but, in addition, is also a filter enabling a single wavelength to be selected and transmitted from the incoming light. Unlike an AOM, which works with one laser line, an AOTF can be used with multiple laser lines simultaneously. It can also be used with broadband light sources such as xenon and halogen. The main advantage of AOTF compared with conventional fluorescence filters is the absence of any moving part leading to stable and fast wavelength tuning. AOTFs, in addition, do not deteriorate when exposed to heat and intense light. Radio frequencies applied to the AOTF transducer control the frequency corresponding to the wavelength range, while radio frequency amplitude adjustments allow the light intensity to be modulated.
AOTF are widely used in many optical systems and applications. AOTF technology, however, is especially valuable in live cell imaging, where fine control of wavelength and intensity help to reduce phototoxicity and photobleaching of fluorophores especially in long-term time-lapse imaging applications. Like AOM's, AOTF's allow light modulation with very high frequencies, which allows targeted bleaching or activation in techniques such as FRAP or PA-GFP imaging.
Nikon's LiveScan Sweptfield confocal system incorporates a very fast AOTF for precise control over the transmitted wavelength and intensity of laser light. It takes advantage of up to six AOTF modulated laser lines for single or multi-channel sequential data acquisition. Configured with Nikon's Ti-PFS series microscopes or the FN-1 physiology station, the LiveScan offers particular flexibility in live cell fluorescence and time-lapse imaging.
Nikon's LiveScan Sweptfield confocal system.