Abstract: Output pulses from an optical system having a seed source and an optical amplifier coupled to the seed source may be controlled by controlling a power of a seed signal from the seed source. The seed signal may be varied between a minimum value and a maximum value in a way that the seed signal exhibits one or more pulse bursts. Each pulse burst may contain one or more pulses. During an inter-pulse period between successive pulses within a pulse burst or between successive pulse bursts, the power of the seed signal may be adjusted to an intermediate value that is greater than the minimum value and less than the maximum value. The intermediate value is chosen to control a gain in the optical amplifier such that a pulse or pulse burst that follows the period exhibits a desired behavior.

Abstract: Output pulses from an optical system having a seed source and an optical amplifier coupled to the seed source may be controlled by controlling a power of a seed signal from the seed source. The seed signal may be varied between a minimum value and a maximum value in a way that the seed signal exhibits one or more pulse bursts. Each pulse burst may contain one or more pulses. During an inter-pulse period between successive pulses within a pulse burst or between successive pulse bursts, the power of the seed signal may be adjusted to an intermediate value that is greater than the minimum value and less than the maximum value. The intermediate value is chosen to control a gain in the optical amplifier such that a pulse or pulse burst that follows the period exhibits a desired behavior.

Abstract: Power consumption at a site is monitored. An electrical load is connected to a power source by an electrical conductor. A fuel-less energy producing device is electrically connected to a junction along the electrical conductor. A current sensor is electromagnetically coupled to the electrical conductor at a sensing position between the power source and the junction to create a current sensor signal. Sensed current and voltage signals are produced from the current sensor signal. A sensed phase relationship between the sensed signals is determined and compared to a baseline phase relationship to determine the direction of current flow through the conductor. A power source signal, based on the current flowing through the conductor at the sensing position, is created. With some examples a Rogowski type differential current sensor is used. In some examples a single current sensor is used.

Abstract: Power consumption at a site is monitored. An electrical load is connected to a power source by an electrical conductor. A fuel-less energy producing device is electrically connected to a junction along the electrical conductor. A current sensor is electromagnetically coupled to the electrical conductor at a sensing position between the power source and the junction to create a current sensor signal. Sensed current and voltage signals are produced from the current sensor signal. A sensed phase relationship between the sensed signals is determined and compared to a baseline phase relationship to determine the direction of current flow through the conductor. A power source signal, based on the current flowing through the conductor at the sensing position, is created. With some examples a Rogowski type differential current sensor is used. In some examples a single current sensor is used.

Abstract: Methods and apparatus for managing thermal loads on a laser gain medium and for boosting the output power of a diode pumped laser are disclosed. The short-term average pumping power to the gain medium is increased, to provide a burst of pumping energy to the laser gain medium. A subsequent short-term reduction in the average pumping power then allows the gain medium to cool to a desired state steady level. The average pumping power is then increased to maintain this steady state level until the next burst is desired. For example, a pulse of current may be applied to a laser diode at a first current level I1 for a first time interval ?t1, where I1 exceeds a nominal current value Inom by an amount ?I1. The current to the laser diode is reduced to a second current level I2 for a second time interval ?t2, where Inom exceeds I2 by an amount ?I2. To balance the thermal load on the diode an integral of ?I1 over the time ?t1 is approximately equal in magnitude to an integral of ?I2 over the time ?t2.

Abstract: Methods and apparatus for calibrating a frequency difference between two or more lasers over an extended frequency range as well as optical signal generators that employ such an apparatus or method are disclosed. The lasers are tuned in coordination with respect to one or more readily characterized narrow frequency ranges to characterize one or more tuning parameters of each of the lasers over the extended frequency range. The apparatus may include first and second tuning controllers respectively coupled to the first and second lasers, an optical coupler optically coupled to the first laser and the second laser, a frequency detector coupled to the optical coupler and a controller coupled to the frequency detector and the temperature controllers. The controller may include a processor and a memory containing processor executable instructions for calibrating the two lasers in accordance with the method described above.

Abstract: Methods and apparatus for calibrating a frequency difference between two or more lasers over an extended frequency range as well as optical signal generators that employ such an apparatus or method are disclosed. The lasers are tuned in coordination with respect to one or more readily characterized narrow frequency ranges to characterize one or more tuning parameters of each of the lasers over the extended frequency range. The apparatus may include first and second tuning controllers respectively coupled to the first and second lasers, an optical coupler optically coupled to the first laser and the second laser, a frequency detector coupled to the optical coupler and a controller coupled to the frequency detector and the temperature controllers. The controller may include a processor and a memory containing processor executable instructions for calibrating the two lasers in accordance with the method described above.

Abstract: Pulse recovery times are reduced in a pulsed intracavity frequency-converted laser by operating the laser in a continuous-wave (c.w.) mode before operation in a Q-switched mode. C.w. light locally optically heats the frequency-conversion optics of the laser to facilitate phase-matching at the beginning of Q-switched operation. C.w. operation also reduces the amplitude of the first pulse of the subsequent firing sequence by expending population inversion accumulating in the gain medium. Operation in c.w. mode is initiated by ramping up the net optical gain in the laser cavity when the time elapsed since the latest emitted pulse exceeds 110% of the interpulse spacing prior to the latest pulse. Initiation of c.w. operation does not require external signals other than optionally a pulse trigger sequence from the user. Cavity optical losses may be increased immediately prior to the first pulse, for accumulating population inversion and increasing the first pulse to a desired level.