摘要:

We report a study of the time evolution of differentgroupsof HgBr (X2&Sgr;+1/2) vibrational level densities which are quenched by collisions with He. Vibrational quenching is efficient down to the lowestv″levels that we are able to monitor, indicating that energy can be efficiently extracted from the HgBr (B→X) laser, even when tuning to frequencies other than those with the highest gain.

ISSN:0003-6951    

DOI:10.1063/1.92168

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

X‐ray streak photography of the interaction of a nanosecond CO2laser pulse with large‐diameter foil targets shows the presence of an annular x‐ray emitting region which expands away from the focal spot with a veclocity up to 109cm/sec. This region exhibits laser‐polarization‐dependent asymmetry, and it is postulated that it is formed by a return current of fast electrons bombarding the front of the target foil. It appears likely that this phenomenon is responsible in part for anomalous lateral energy transport and magnetic field generation in such experiments.

ISSN:0003-6951    

DOI:10.1063/1.92169

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Films of ZnS have been deposited by rf sputtering and subsequently implanted with Al. Examination of the conductivities, after annealing, shows that Al is effective in decreasing the film resistivity. At ∼ 300 K the room‐temperature conductivity could be reduced to 10−2&OHgr;−1 cm−1compared with 10−10&OHgr;−1 cm−1in undoped films. The small activation energy of ∼ 0.1 eV of the electrical conductivity and the temperature dependence of the thermoelectric power may possibly be indicative of impurity conduction.

ISSN:0003-6951    

DOI:10.1063/1.92170

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

We report pulses as short as 8 ps obtained from a mode‐locked cw optically‐pumped semiconductor laser. The sample was a CdS platelet at a temperature of 95 K longitudinally pumped by a mode‐locked Ar+laser. The output power was 3.2 mW with 8‐ps pulses, and powers greater than 10 mW have been observed with 10‐ps pulses. Laser performance is quite independent of cavity length as compared to synchronously pumped dye lasers, indicating that passive pulse shaping may be taking place.

ISSN:0003-6951    

DOI:10.1063/1.92171

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Optical time domain reflectometry by backscattered light in a single‐mode fiber is demonstrated. The experiment employs a novel efficient single‐mode/multimode coupling device and also a powerful and versatile multiwavelength mode‐locked and pulsed optical source.

ISSN:0003-6951    

DOI:10.1063/1.92147

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

We report the separate TE01and TE02operation of a CO2laser in a hybrid oscillator formed by placing a circular metallic waveguide and a focusing lens inside the cavity of an otherwise conventional laser. With the TE01output focused into a passive waveguide outside the cavity, transmission in excess of 90% has been measured through a 31‐cm‐long, 0.5‐mm‐i.d. straight metallic tube. Bending increased the losses far more than originally anticipated.

ISSN:0003-6951    

DOI:10.1063/1.92172

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

A method for absolute two‐photon cross‐section‐value &ggr;2evaluation by means of one‐ and two‐photon fluorescence comparative measurements and using a low‐power, single‐mode cw laser is presented. This method is applied to a rhodamine B solution. The experimental value &ggr;2we obtained is compared with previous experimental data measured by a high‐power laser source.

ISSN:0003-6951    

DOI:10.1063/1.92173

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Hysteresis in piezoelectric transducers down to 20 A˚ and gas pressure changes as small as 10 mTorr are measured by locking a laser FM sideband to an interferometer resonance. In addition, rapid monitoring of large excursion motions with 200‐A˚ accuracy is achieved using an ’’optical frequency comb’’ consisting of multiple FM sidebands.

ISSN:0003-6951    

DOI:10.1063/1.92174

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Flashlamp excitation of H2O vapor in the 10–80‐mTorr pressure range has produced a population inversion on the (001), g = 3, 954−945transition. This has resulted in a modulated emission at 115 cm−1. The oscillations on the amplified spontaneous‐emission signal are interpreted as quantum beats between magnetic hyperfine levels split by anI⋅Jinteraction. Analysis of the data results in a splitting of 1.4 MHz and dephasing rates of 7.8 MHz/Torr for H2O‐H2O, 0.5 MHz/Torr for He‐H2O, and 1.7 MHz/Torr for Ar‐H2O mixtures.

ISSN:0003-6951    

DOI:10.1063/1.92148

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Optical bistability is realized using a Faraday rotator which has a high rotating power owing to multiple reflections in a planar glass plate. The linearly polarized light is modulated by the coil current of the electromagnet. Optical hysteresis is observed when the current is changed in proportion to the intensity of the light transmitted through the modulator. An application of this device to stabilizing the light intensity of the cw laser intensity is described.

ISSN:0003-6951    

DOI:10.1063/1.92149

出版商:AIP    

年代:1981

数据来源: AIP