For Probing of Cells and Tissue in Microbial Mats and Leaves
The MICROFIBER-PAM employs a very thin optical fiber for fluorescence excitation and detection. This narrow fiber permits probing of small spots of heterogeneous photosynthetic surfaces like soil crusts.
Also, placing the microfiber at different penetration depths permits measurements of photosynthetic gradients within microbial mats and leaves.
The central part of the MICROFIBER-PAM is a fiber optic coupler consisting of a “beam splitter” to which two pairs of fibers are connected. This “four-port” coupler distributes light incoming from one fiber pair to the other pair where each fiber pair can function as input.
Typically, the fiber optic coupler conducts emission from an LED to the sample, and guides fluorescence from the sample back to a highly sensitive photomultiplier which is shielded against LED light by glass filters.
Both light emission of the LED and fluorescence measurement by the photomultiplier are coordinated by the PAM-CONTROL unit.
The PAM-CONTROL unit allows stand-alone operation of the MICROFIBER-PAM but functions also as a physical interface for computer-controlled operation of the MICROFIBER-PAM.