UV laser-induced current in germanosilicate fibres with built in electrodes

The nature of photocurrents is studied in germanosilicate single-mode fibres with built in electrodes. It is shown that irradiation by excimer KrF laser pulses at electric field strengths up to 1.6 MV cm^-1 causes a charge formation and transfer in the core of the fibre and the injection of photoelectrons from metal electrodes to the fibre cladding. Both effects facilitate the flow of electric current through the sample. The dependences of the photocurrent on the electric field strength, the energy density in the laser pulse, the fibre temperature, and the impurity hydrogen in the fibre core are obtained.