Abstract: An object of this invention is to provide an imaging device which can output distinct images which are not blurred. According to this invention, photoelectrons emitted from a photocathode (2) during a gate period in which a low potential change is given to the photocathode have set energy different from that of photoelectrons during the other period, and are incident on an energy filter (9). Only photoelectrons of the set energy pass through the energy filter (9). The photoelectrons which have passed through the energy filter during a gate period advance to an output surface (3).

Abstract: Time-dependent information such as light whose intensity varies with time is converted into positional information representing the change of the time-dependent information. A series of photoelectrons provided as the time-dependent information are accelerated or decelerated when passing through a region defined by first and second electrode to which a ramp voltage is applied so that the photoelectrons are accelerated or decelerated and are released at speeds varying depending on times. A speed analyzer analyzes the speeds of the photoelectrons and provides the positional information. The positional information is applied to a phosphor screen on which the positions of the photoelectrons applied thereto are displayed. The positions thereof represents the times involved with the photoelectrons.

Abstract: When sampling light and light to be measured each having a wavelength longer than an upper wavelength limit of the sensitivity of a photocathode are incident on the photocathode of a multiphoton absorption-type electron tube, light-light sampling is enabled by two-photon absorption and one-photoelectron emission. A delaying unit adjusts an incident timing of the sampling light from an optical pulse generating unit on the elctron tube in synchronism with an incident timing of the light to be measured on the electron tube. A half mirror causes the sampling light and the light to be measured to coincide on the photocathode of the electron tube. A controlling unit controls the delaying unit to sequentially shift the incident timing of the sampling light on the electron tube.

Abstract: A streak camera for detecting a light signal representing optical events occurring in ultra-short time intervals, comprising a photocathode, an accelerating electrode, a focusing electrode, an anode, a traveling wave deflector having a deflecting electrode for deflecting photoelectrons emitted from the photocathode with a deflection voltage having a phase velocity, a deflection circuit for controlling the deflection voltage to be applied to the deflecting electrode of the deflector, an electron stream detector having for detecting the electron stream deflected by said deflector, and a voltage control unit for controlling voltages to be applied to the photocathode, the accelerating electrode, the focusing electrode, the anode and the electron stream detector, thereby controlling a potential distribution in a photoelectron transit path.