A short actively mode-locked XeCl oscillator has produced 120-ps duration pulses for the first time. The pulses have an energy of 15 μJ and a modulation depth of >95%. The evolution of the pulsewidth during the mode-locked pulse train was also measured.

Relative efficiency of 2 0 0Hg7 9Br, Hg7 9Br, and HgBr electric discharge lasers Appl. Phys. Lett. 43, 622 (1983); 10.1063/1.94464 A kinetic model of the sustained discharge HgBr laser

We have resolved the controversy in the literature concerning the dominant excitation mechanism of the cw mercury ion laser by obtaining the first direct experimental proof that thermal energy charge transfer is the dominant formation process for the excited 7p2P terms of Hg II which support cw laser oscillation of 6150 and 7944 Å. Using a floating double probe we have monitored directly the helium ion density versus time and confirmed its one-to-one correspondence with the measured decay of spontaneous emission from the Hg II 7p2P levels. The measured value of the cross section, σ (He+-Hg), is 1.3×10−14 cm2, amongst the largest ever observed in atomic physics, and confirms earlier work by Dyson.

Excitation-transfer cross sections have been measured for Penning and charge-transfer reactions in He-Ca, He-Sr, Xe-Ca, and Xe-Sr discharges. In low-current low-pressure discharges of helium, excitation transfer to ionic levels of calcium and strontium was found to be dominated by collisions with 23S helium metastables with measured cross section σ (He 23S–Ca) =4.1×10−15 cm2 and σ (He 23S–Sr) =1.6×10−15 cm2. In xenon discharges, charge-transfer cross sections between xenon ions and calcium and strontium atoms, σ (Xe+-Ca) and σ (Xe+-Sr), were measured to be 2.2×10−16 and 2.3×10−16 cm2, respectively.

Articles you may be interested inConservation of the Kr+(2 P 1/2) state in the reactive quenching of Kr(5s′[1/2]0) atoms by halogencontaining moleculesInterpretations of the mercury halide (B 2Σ+-X 2Σ+) chemiluminescence from reactive quenching of Hg(3 P 2) by halogen containing molecules J. Chem. Phys. 79, 5423 (1983); 10.1063/1.445706Quenching and reactions of laserexcited I(52 P 1/2) atoms with halogen and interhalogen molecules