Generation of ultrawideband electromagnetic radiation by a vacuum photodiode with anode with a sapphire input window

Investigations of the generation of ultra-wideband electromagnetic radiation by a vacuum photodiode with a flat antimony-cesium photocathode have been carried out. The anode of the photodiode was a set of thin aluminum strips applied to the input sapphire window. The emission of electrons from the photocathode was initiated by the second harmonic radiation ($\lambda$ = 385 nm) of titanium - sapphire laser system with a pulse duration of 200 fs. Measurements of the strength of the electrical component of electromagnetic radiation were performed when the voltage across the interelectrode gap changed from 13 to 140 kV.