A charge accumulating diode as register and meter of weak light fluxes

Physical processes are studied in an inversely biased $p-n$ junction of a photodiode operating in the charge accumulation mode and subjected to «exposure». The advantages of accumulation over instantaneous response are noted. A circuit implementing the accumulation modd for a silicone ФД-7К photodiode is proposed. An experimental unit displaying registration level of light fluxes and calibrating a meter of weak light fluxes at 700 nm. is described. Characteristics are given for a power meter using an accumulating photodiode fo continuous and discontinuous light fluxes ranging from $10^{-4}$ to $10^{-8}$ W.