Abstract: A handheld portable battery powered digital antenna and/or network analyzer which derives complex impedance values at a given frequency includes an internal direct digital synthesis generator and provides software-defined multiple operating modes and real time graphic scalar and polar displays of results in a multiplicity of user-selectable visual formats.

Abstract: A photometer including an elongated sample cell having a first end, a second end, and a passageway extending between the first end and the second end. Preferably, a ratio of a length of the sample cell to a lateral dimension of the passageway is at least 100 to 1. A first quartz window assembly is located at the first end of the sample cell and has a first port communicating with the passageway proximate to the first end, and a second quartz window assembly is located at the second end of the sample cell and has a second port communicating with the passageway proximate to the second end. An ultraviolet lamp is positioned to emit ultraviolet light through the first quartz window, the passageway, and the second quartz window, and an ultraviolet detector is positioned to receive the ultraviolet light emanating from the second quartz window. Preferably, the sample cell is operated at about ambient temperature, and the volume of the sample cell is no greater than about 0.

Abstract: A power switching circuit for providing variable pulse width drive signals for a laser in response to pulsed control signals. The power switching circuit includes a transformer circuit and a power transistor output circuit. The transformer circuit comprises a first pair of primary windings coupled to input terminals through a switch and an associated pair of secondary windings coupled to the output circuit to apply switching signals thereto. The transformer circuit further includes a second pair of primary windings coupled through a resistor to the input terminals with a polarity opposite that of the first pair. Control signals having a pulse width and repetition rate associated therewith are applied to the switch. During inter pulse intervals the voltage applied to the second pair of primary windings biases the transformer into saturation in a direction opposite to that of the first pair.

Abstract: A pulsed laser system capable of operating in a plurality of modes for delivering a burst of laser pulses to a target wherein the pulse width of the laser pulses are automatically controlled in response to the mode selected. A special calibration procedure allows the system to determine the pulse width and pulse repetition rate when the laser is producing a predetermined power output level as measured by a power meter at the target site. Using calibrated pulse width and pulse repetition rate, the pulse width and pulse repetition rate of the laser pulses to be delivered to the target for any particular treatment burst can be determined. Means are provided for determining the energy delivered to the target for any particular treatment burst. A potentiometer coupled to a laser spot size control lens assembly provides a signal proportional to the spot size. From this signal and the energy delivered, the energy density can be calculated.