Wide-frequency hydrophone detection of laser-induced photoacoustic signalsin photosynthesis

A feasibility study was made on the use of a wide-frequency band hydrophone to detect photoacoustic signals, particularly for the evaluation of photoc hemical activity of photosynthetic systems in suspension and in leaves, Dep ending on the experimental arrangement, signals could be detected over more than 100 mu s following a picosecond laser hash, Particularly important wa s the success to obtain modulated signals in response to modulated light in the kHz frequency range. These results are a step toward frequency domain measurements in a frequency range between about kHz and MHz that has not be en Set accessible to calorimetric photoacoustic measurement and that is ext remely important in photosynthesis.