摘要:

Experiments on the dynamic stabilization of the Rayleigh‐Taylor instability are described, where the applied oscillations are modulated in their frequency or chosen to be strongly anharmonic. While, compared to the application of harmonic oscillations, an expected rise of the excitation threshold of parametric instabilities could be observed, a corresponding shift of the boundary discriminating against the slowest Rayleigh‐Taylor mode did not allow to obtain a measurable increase of the over‐all stability region.

ISSN:0003-6951    

DOI:10.1063/1.1654765

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

A new principle for optical isolation based on the saturation of a Doppler‐broadened resonance is described. It depends on an initial difference in the power levels of the incident and reflected waves. The technique is demonstrated using an SF6absorber to isolate theP(18) line of the CO2transition at 10.57 &mgr;m.

ISSN:0003-6951    

DOI:10.1063/1.1654766

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Non‐dopant ions have been implanted at low doses ([inverted lazy s] 1010cm−2) into GaAs to determine the extent of carrier removal and to pin‐point annealing stages for carrier recovery. A removal rate of around 200 carriers per ion is found for such lighter ions as B+, N+, and F+. At the 1‐MeV energy used, compensating damage extends along the ion track right from the GaAs wafer surface. Partial recovery of the carriers as well as mobility occurs at the well‐known 225 °C electron damage annealing stage. A further annealing stage is found at [inverted lazy s] 525 °C.

ISSN:0003-6951    

DOI:10.1063/1.1654767

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Modulation of essentially thermionic forward current by light‐induced lowering of an electrostatic barrier leads to steady‐state electron per photon gain of order 106in narrow Cu‐compensated Au/CdS junctions. The light dependence of the barrier, whose peak lies within the semiconductor, is measured directly by internal photoemission. A model of the junction is presented and the limiting threshold and gain of this type of device is estimated.

ISSN:0003-6951    

DOI:10.1063/1.1654768

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Single heterojunction diode lasers in the Pb1−xSnxTe alloy system have been fabricated by low‐temperature vacuum deposition ofn‐PbTe on ap‐Pb0.88Sn0.12Te substrate. The lasers have lower threshold current densities and operate cw at higher temperatures than homojunction devices in this material. At laser threshold the incremental diode resistance drops abruptly from 0.5 &OHgr; to a series resistance limited value of 0.08 &OHgr;, a previously unobserved effect in diode lasers which indicates very high internal quantum efficiency.

ISSN:0003-6951    

DOI:10.1063/1.1654769

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

An electric dipole moment is induced in homonuclear molecules during collisions, allowing radiative transitions which are otherwise forbidden. This effect, coupled with high‐pressure electrical excitation, may be used to achieve laser action in a homonuclear gas. Properties of this type laser include a very broad gain bandwidth and a new type of partial inversion. A mixture of H2and Xe is analyzed as a prospective system wherein efficiencies of about 20% are predicted for picosecond pulses at 2.8 &mgr;m.

ISSN:0003-6951    

DOI:10.1063/1.1654770

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

A cw O/CS2CO chemical laser has been operated at a chemical efficiency of 37.5%. This result was achieved by the use of N2O as a diluent whoseV‐Vtransfer effects on the chemically formed CO are such as to strongly enhance emission in the low vibrational bands. The free‐running oscillator spectra start atv= 12 → 11 and continue tov= 2 → 1, with more than 50% of the output in the low bands 6 → 5 to 2 → 1. These results again emphasize the importance of vibrational energy transfer in chemical laser media.

ISSN:0003-6951    

DOI:10.1063/1.1654771

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Transverse spatial periodic breakup of an optical beam due to self‐focusing has been experimentally observed. Each focal spot evolves from a zone with well‐defined dimensions. The formation from these zones is consistent with an instability theory. Calculated and experimentally observed zone dimensions and powers are in good quantitative agreement.

ISSN:0003-6951    

DOI:10.1063/1.1654772

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Holographic interferograms are produced on gelatine films with pulsed HF laser light (&lgr; ≈ 3 &mgr;m). The sensitivity is about 2 J/cm2, and the resolution at least 300 lines/mm. The spectrum of the HF laser is measured by means of holography.

ISSN:0003-6951    

DOI:10.1063/1.1654773

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Kreuzer has demonstrated the feasibility of detecting atmospheric pollutants using acoustic signals produced by volumetric absorption of infrared radiation. We have investigated a substantial improvement of this technique wherein the optical excitation beam is modulated at a frequency corresponding to a natural acoustic resonance of the sample chamber. Acoustic amplification factors exceeding 100 have been observed.

ISSN:0003-6951    

DOI:10.1063/1.1654774

出版商:AIP    

年代:1973

数据来源: AIP