摘要:

We have demonstrated a new approach to controlling millimeter wave propagation with light. Phase shifts as high as 300°/cm of 94‐GHz millimeter waves were observed accompanied by less than 1 dB insertion loss. A straightforward model was found to account in detail for the observed behavior.

ISSN:0003-6951    

DOI:10.1063/1.91212

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

A structure to avoid nonlinearities in the light‐output versus current is proposed in long wavelength lasers of InGaAsP. This structure is very similar to a channeled‐substrate planar laser in GaAlAs system. As in the GaAs lasers, nonlinearities are significantly reduced by introducing a built‐in passive wave‐guiding mechanism.

ISSN:0003-6951    

DOI:10.1063/1.91213

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

Spatially resolved laser‐induced fluorescence has been used to observe and measure the isotope shift for atomic lithium in the 22P←22Stransitions. A modified saturated absorption spectrum was also obtained for the ’’overlapping’’ transitions. The7Li‐6Li isotope shift in the absence of fine and hyperfine splittings is calculated to be 1 0532±5 MHz.

ISSN:0003-6951    

DOI:10.1063/1.91214

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

Tunable submillimeter radiation, generated and detected using optically pumped lasers and Schottky diode mixers, has been used in an infrared‐submillimeter double resonance investigation of CH3F. This technique permits the direct observation of the molecular rotational spectra and kinetics of excited vibrational states and is particularly important for those molecules which are candidates for optically pumped submillimeter lasers.

ISSN:0003-6951    

DOI:10.1063/1.91215

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

A photoacoustic (PA) signal dependence on Si crystal quality has been observed. The signal behavior has been investigated and on the basis of present evidence appears consistent, under conditions described in the letter, with PA theory as recently extended to include two‐layer systems. Results of this study have potential use in laser annealing applications because they may provide a means of rapidly evaluating the degree of recrystallization, using the annealing laser beam set at a lower power level for PA excitation.

ISSN:0003-6951    

DOI:10.1063/1.91216

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

A new dual‐wavelength light‐emitting diode (LED) emitting near 1.2 and 1.3 &mgr;m has been fabricated. The differential efficiencies of the two outputs were 0.36 and 0.88%, respectively. The intensities of these optical outputs can be controlled independently. The optical cross talk between the two wavelengths was −10 and −16 dB at 1.15 and 1.35 &mgr;m, respectively. This device is useful for wavelength‐multiplexed optical communication systems.

ISSN:0003-6951    

DOI:10.1063/1.91217

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

The Synchroscan streak camera system has been used to examine the temperature dependence of the fluorescence decay of trans‐Stilbene between ‐10 and 30 °C. Two components of the fluorescence have been detected; a short one varying between 125 and 64 psec over the range and a much weaker longer one varying from 690 to 1450 psec. The presence of the longer component may indicate a return to the transgeometry following initial photoisomerization.

ISSN:0003-6951    

DOI:10.1063/1.91218

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

A technique has been developed for measuring the temperature dependence of elastic moduli of metals and alloys using electromagnetic excitation of acoustic resonance in small spheres polished optically smooth. A frequency swept marginal oscillator is used to generate and detect resonances without physical contact to the sample. Values ofCijare reproducible with accuracies of ∼1/104. Variations of ∼1/106are detected using an oscillator mode which is phase locked to sample resonance. Measurements ofC44and (1/2)(C11−C12), from 300 to 4.2 K, on a 4.7‐mm‐diam. tungsten sphere are given to illustrate the technique.

ISSN:0003-6951    

DOI:10.1063/1.91219

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

Lead titanate PbTiO3ceramics with a zero temperature coefficient of surface wave delay time are developed by addition of Nd2O3, In2O3, and MnO2. These ceramics have very small temperature coefficients of less than 1 ppm/ °C over a wide temperature range (−10–+60 °C). They have a large electromechanical coupling factor and low dielectric constant. The propagation loss is 4 dB/cm at 57 MHz. These modified PbTiO3ceramics have high potential for use in surface wave applications, e.g., filters.

ISSN:0003-6951    

DOI:10.1063/1.91220

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

DT‐filled 115‐&mgr;m‐diam. glass microballoons have been irradiated with the six‐beam ZETA laser (Nd: phosphate glass) at 2 TW. The absorption uniformity and implosion symmetry have been studied with x‐ray imaging for variations in the laser focal conditions. Symmetry, as indicated by the x‐ray spatial emission of both the absorption region and the imploded core, has been found to be a strong function of illumination uniformity.

ISSN:0003-6951    

DOI:10.1063/1.91221

出版商:AIP    

年代:1979

数据来源: AIP