Abstract: Electrical signals are measured (analyzed and displayed) with picosecond resolution and sensitivity in the microvolt (less than 100 microvolts) range by electron-optically sampling the signal. Sampling electron bursts are produced in response to a train of subpicosecond optical pulses. A beam of these electron bursts samples successive portions of the signal as it is transmitted as a travelling wave along deflection plates which act as a transmission line. The bursts are deflected in accordance with the amplitude of the successive portions of the signal and translated into spots of light, as on a phosphor screen. The deflection is significantly less than the diameter of the spot. The deviation of the spot with respect to the position thereof in the absence of the signal on the deflection plates is translated into a difference output. The signal to be analyzed is generated, synchronously with the optical pulses, to propagate along the deflection plates in variably delayed relationship therewith.

Abstract: Picosecond switching of electric current in response to optical signals is obtained by conversion of the optical signal, such as an optical pulse, into a photoelectron burst (a photoelectronic signal) which is a faithful temporal replica of the optical signal. Electron optics increase the energy of the electrons of the photoelectronic signal which is imaged so as to illuminate essentially the entire gap formed between electrodes on a body of semiconductor material. The photoelectrons are absorbed in the semiconductor material to create throughout the gap a degenerate layer. The gap geometry and the image formed by the optical signal on a photocathode, which provides the photoelectronic signal, are such that space charge effects do not distort the photoelectronic signal and a temporal replica of the optical signal illuminates the entire gap. The gap geometry affords broad bandwidth operation.

Abstract: A laser system generates high energy ultra-short pulses using a dye cell amplifier driven by ultra-short pulses from a dye laser and pumped by pump pulses from a laser amplifier. The laser amplifier and dye laser are synchronously driven and pumped by the same laser such that the signal pulse from the dye laser arrives at the dye cell amplifier immediately upon the completion of population inversion therein in response to the pump pulse. Efficient high-power, ultra-short laser pulses are obtained from the dye amplifier, since amplified spontaneous emission (ASE) is avoided. Doubler crystals are used to provide the pump pulses to the dye laser from the common driver laser and to provide pump pulses from the laser amplifier to the dye cell amplifier at the proper wave length for the materials used therein. This system is tunable by selecting appropriate dyes for the dye laser and dye cell amplifier and/or tuning elements within the dye laser cavity.

Abstract: An inexpensive, simple and highly accurate sweep drive circuit for streak cameras generates a ramp voltage for the deflection plates of an image converter tube of a streak camera. A solid state switch is used in a manner which eliminates the need for a pulsed multi-kilovolt bias voltage and the use of cryogenics. High voltage direct current in the multi-kilovolt range is applied to a charged circuit which may include a high voltage capacitor or use the capacitance presented by the deflection plates of the tube. The switch is laser activated and becomes photo-conducting. The charge in the capacitor passes through a charging resistor which controls the sweep rate to the deflection plates. After the activating laser pulse, the switch returns rapidly to a nonconducting state, during the recombination time of the switch material. The photo-electron beam is swept linearly over a substantial portion of the recombination time from off the image forming phosphor screen to off screen on the other side thereof.

Abstract: A body of semiconductor material is biased with multi-kilovolt voltage to establish an electric field approaching the dielectric breakdown field for the semiconductor material. Low level optical energy, such as a laser pulse in the nano-joule range produces free carriers in the semiconductor which multiply in the presence of the electric field to produce avalanche conduction through the semiconductor body thereby switching the multi-kilovolt voltage in precise timed (picosecond) relationship with the application of the optical energy and with high switching or turn on sensitivity.

Abstract: Picosecond duration microwave pulses are generated used a laser activated semiconductor switch. High voltages are switched with picosecond rise time and result in the establishment of microwave pulses of frequency spectrum commensurate with the rise time of the voltage and wave guide parameters of a wave guide in which the switch is disposed. The activating light pulse is synchronous with the microwave pulse. A system, including an antenna and radar receiver, is responsive to the light pulse and return signals from a target on which the microwave pulse is incident. Reflection measurements of the microwave pulses from a body of semiconductor material which is optically excited by the light pulses relatively delayed between the generation of successive microwave pulses, indicate the duration of the microwave pulses.

Abstract: A semiconductor body, having deep lying charge carrier trapping centers, as by being doped with a deep-lying impurity to a concentration such that, at cryogenic temperature, the body is capable of holding off a multi-kilovolt DC bias without thermal instability and of switching the bias with picosecond accuracy to generate pulses of selected durations beyond the subnanosecond range when activated by optical pulses, as from a laser, which are incident thereon.

Abstract: Switching of high voltage pulses (of the order of 10 kV) of durations from about 10.mu.s (microseconds) to 10ms (milliseconds) with picosecond accuracy is accomplished by a laser activated semiconductor switch made up of a body (18) of high resistivity semiconductor material, such as nearly intrinsic silicon, integrated into a wide band (10GHz) geometry, which is part of a transmission line (28). The high bias voltage pulses are obtained by charging the line in synchronism with the generation of the laser pulse. The high voltage bias pulse width can be typically in the range of 10.mu.s- 10ms, and the length of the body (18) is selected so as to prevent thermal breakdown of the semiconductor with such pulse widths. The energy of the laser pulse switches the high voltage to produce a multikilovolt output pulse suitable for driving devices, such as streak cameras or Pockels cells, by the same laser, which need to be synchronized with picosecond accuracy to the laser pulse.