@ARTICLE{Achtenberg_K._Optical_2019, author={Achtenberg, K. and Mikołajczyk, J. and Szabra, D. and Prokopiuk, A. and Bielecki, Z.}, volume={vol. 27}, number={No 3}, journal={Opto-Electronics Review}, pages={291-297}, howpublished={online}, year={2019}, publisher={Polish Academy of Sciences (under the auspices of the Committee on Electronics and Telecommunication) and Association of Polish Electrical Engineers in cooperation with Military University of Technology}, abstract={The paper presents a new construction of an optical pulse amplitude monitoring unit (PAMU) used in a transceiver of Free Space Optics. It consists of a buffer, constant fraction discriminator (CFD), delay line, and a sample and hold (S&H) circuit. In the design FSO system, the PAMU provides to monitor transmitted and received optical pulses with duration of few ns. Using this device, there is no need to apply complicated and expensive digitizing systems. The unique aspect of its construction is to control S&H circuit using the CFD. The lab model of this unit allows to perform tests to define some virtues of constant fraction and leading-edge discriminators. The results were implemented in optical signal monitoring of FSO system. The unit was prepared to cooperate with two different detection modules. Using this setup, it was possible, e.g. to determine operation characteristics of FSO transmitter, identify interruption of transmission, and control light power to provide high safety of work.}, type={Article}, title={Optical pulse monitoring unit for Free Space Optics}, URL={http://ochroma.man.poznan.pl/Content/115264/PDF/opelre_2019_27_3_291-297.pdf}, keywords={Pulse amplitude monitoring unit, Peak detector, Sample and hold (S&H) circuit, Free space optical communications, Constant fraction discriminator}, }