Abstract: An array of elemental electrodes, each electrode serving in a dual manner as a light sensitive source of photoelectrons, a primary photocathode, and as a collector of electrons for an auxiliary light sensitive input photocathode, followed by a pair of accelerating-retarding field grids and a light emitting phosphor screen to convert electrons passing the retarding field grid to a visible output image. An input optical image, to be processed, impinges on the primary photocathode, while a biasing flood light is provided to excite electrons from the auxiliary photocathode acting as a control on the level at which switching to visible output brightness occurs.

Abstract: A vacuum tube photodetector includes a planar photocathode, a parallel high voltage accelerating mesh, and a planar output anode positioned adjacent to and spaced from the mesh. The anode and mesh are connected to the inner and outer concentric conductors of a high frequency coaxial transmission line coupled to a load or output device. The high voltage preacceleration of electrons by the mesh and the small mesh to anode spacing provide a significant reduction of electron transit or pulse rise time compared with known two element biplanar photodiodes. In addition, the vacuum seal between the anode and mesh is positioned adjacent the anode-mesh gap which greatly reduces pulse decay time and undesired reflections. The mesh and anode are at the same potential to eliminate the usual high bias voltage between inner and outer coaxial photocathode and anode electrodes of the biplanar tube, as well as a coaxial coupling capacitor.

Abstract: A fast scanning optical cathode ray tube with an array of electron multiplier output channels across the sweep path provides demodulation of short pulse code modulated optical signals. The cathode ray tube includes a photocathode, accelerating grid and fast sweep deflection electrodes to direct electron pulses successively across the plurality of output channels. The scanning is synchronized with the repetition rate and time of the incoming light pulses so that each channel accepts only pulses occurring during a particular time interval of the scan.