Abstract: A pulsed diode light source driver includes a variable output power supply, an output capacitor, a switchable linear current driver, a temperature sensor, a conditioning circuit, and a voltage monitor. The temperature sensor monitors the temperature of the capacitor while the voltage monitor circuit monitors the output voltage level. The conditioning circuit and the voltage monitor cooperatively control the output voltage of the variable output power supply, so that temperature-related changes in the characteristics of the capacitor are compensated for, and a constant current is maintained through the diode load over a desired range of temperature. The driver is suitable for laser diodes and light emitting diodes.

Abstract: A pulsed diode light source driver includes a variable output power supply, an output capacitor, a switchable linear current driver, a temperature sensor, a conditioning circuit, and a voltage monitor. The temperature sensor monitors the temperature of the capacitor while the voltage monitor circuit monitors the output voltage level. The conditioning circuit and the voltage monitor cooperatively control the output voltage of the variable output power supply, so that temperature-related changes in the characteristics of the capacitor are compensated for, and a constant current is maintained through the diode load over a desired range of temperature. The driver is suitable for laser diodes and light emitting diodes.

Abstract: Apparatus and methods for ethanol production use shock waves and pulsed electric fields to increase the conversion of starch and/or cellulosic material into sugar. The shock waves or the pulsed electric fields may also control bacteria levels in the ethanol production facility. The shock waves and the pulsed electric fields may be generated, at least in part, by a pulsed electric field generator such as a Marx generator, which may have one or more semiconductor switches.

Abstract: Apparatus and methods for ethanol production use shock waves to increase the conversion of starch and/or cellulosic material into sugar. The shock waves may also control bacteria levels in the ethanol production facility. The shock waves may be generated by a shock wave generator that includes a pulsed electric field generator such as a Marx generator, which may have one or more semiconductor switches.

Abstract: Apparatus and methods for ethanol production use pulsed electric fields to increase the conversion of starch and/or cellulosic material into sugar. The pulsed electric fields may also control bacteria levels in the ethanol production facility. The pulsed electric fields may be generated by a pulsed electric field generator such as a Marx generator, which may have one or more semiconductor switches.

Abstract: A laser-activated semiconductor switching device includes a semiconductor assembly including a multi-layer semiconductor structure having a first principal surface, and a laser assembly. The laser assembly includes at least one laser device and is directly connected to said first principal surface. The first principal surface includes a window area from which a metallization layer and an emitter layer of the semiconductor assembly are masked, such that laser light emitted from the laser assembly impinges through the window area directly onto a base layer of said semiconductor assembly to initiate current conduction by said switching device.

Abstract: A laser-activated semiconductor switching device has a semiconductor structure housed in a semiconductor structure housing, and a laser array assembly directly connected to the semiconductor structure housing. The laser array assembly houses a plurality of laser diodes and diode control circuitry which energizes the laser diodes to emit light directly onto a surface of the semiconductor structure, which can be the cathode or anode surface, or both, to cause the semiconductor structure to generate current carriers which enable passage of current through the semiconductor structure. The surfaces of the semiconductor structure can be covered with metal layers having openings which permit the passage of the laser light into the semiconductor structure. The metal layers are reflective to the laser light and prevent the laser light that has passed into the semiconductor structure from exiting the structure to improve current carrier generation.

Abstract: Semiconductor switches, such as thyristors, may be light activated by introducing the light into the switch via a groove having a sloped surface to receive the triggering light. The use of a sloped surface increases the surface path length between points of different electrical potential in the groove and, therefore, reduces the likelihood of electrical breakdown on the groove wall. In one particular embodiment, a light-activated thyristor comprises a semiconductor anode layer, an n-base layer, a p-base layer and a semiconductor cathode layer disposed parallel to a thyristor plane. A thyristor axis lies perpendicular to the thyristor plane. A groove having a light refracting side wall extends into the thyristor from the anode layer. A portion of the light refracting side wall is disposed non-parallel to the thyristor plane and to the thyristor axis, and extends in the n-drift layer.

Abstract: The optical modulator of the invention comprises an electro-optic material (EOD) which modulates optical energy in accordance with an applied voltage. The applied voltage is controlled by a light activated switch, or switches, which vary the magnitude of the voltage applied by switching a charge transfer circuit (or other dc source) of which the EOD forms a capacitive element. The charge transfer circuit preferably includes a plurality of capacitive elements, each charged to a separate voltage, so that when switched by said light activated switches, the voltage applied to the EOD is controlled. When used in a laser cavity, the optical modulator can control the output of the laser in response to optical input signals. The optical modulator may be used for Q-switching the laser cavity, mode-locking the laser, cavity dumping the laser or modulating the output of the laser, or a combination of the above.

Abstract: The optical modulator of the invention comprises an electro-optic material or magneto-optic material EOD which modulates optical energy in accordance with an applied electromagnetic waveform. The electromagnetic waveform impressed in the EOD is controlled by a light activated switch, or switches, which varies the magnitude of the electromagnetic waveform to the EOD by switching portions of a transmission line (of which the EOD forms all or at least a part of the dielectric) in or out. The switch, or switches, may be configured between segments of one of the conductors of the transmission line and may overlay the electro-optic dielectric material. The transmission line may include a plurality of sections, each charged to a selected voltage, so that when switched by said light activated switches, the electromagnetic waveform to the EOD is controlled. When used in a laser cavity, the optical modulator can control the output of the laser cavity in response to optical input control signals.