摘要:

Observation of optical guidance in an epitaxial mixed‐crystal film (NH4)xK1−xH2PO4grown on a (100) KDP substrate is reported. The film thickness was ∼38 &mgr;. The ordinary and extraordinary indices of the film forx=0.07 at 589.3 nm werenfo=1.5105 andnfe=1.4695. The difference in corresponding indices between the film and the substrate was 10−3. When the film waveguide was excited by a Gaussian He&sngbnd;Ne laser beam, the distribution of energy across the output face of the crystal confirmed one‐dimensional guiding in the epitaxial film.

ISSN:0003-6951    

DOI:10.1063/1.1654335

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Symmetry considerations reveal that an asymmetry exists relative to orthogonal 60° dislocations of thesame signin zinc‐blende structure. The effect of this asymmetry has been observed in compositionally graded crystals of In1−xGaxP and GaAs1−xPxgrown from vapor phase. It is observed that the spatial arrangement of the two sets of misfit dislocations in an orthogonal array is different. In one ⟨110⟩ direction, the misfit dislocations tend to be uniformly distributed, while in the other ⟨110⟩ direction there is a marked tendency for periodic banding of the dislocations.

ISSN:0003-6951    

DOI:10.1063/1.1654336

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Thermoelectric analysis of the electrical conductivity in Ir(CO3) Br and K2Pt(CN)4Cl0.3·xH2O as a function of temperature and atmosphere gives additional insight into the transport processes involved. The temperature independence of the thermoelectric power measured for Ir(CO3) Br indicates that the observed temperature dependence of conductivity is due to the mobility of the carriers and is consistent with a hopping model for conductivity. Two quite different electronic states of K2Pt(CN)4Cl0.3·xH2O are defined as (i) a high‐conductivity hydrated state withx≈ 2.6, which exhibits a small positive thermoelectric power, and (ii) a lower‐conductivity dehydrated state withx≈ 0, which exhibits a larger negative thermoelectric power. Log conductivity in the former state varies as 1/T1/2, whereas in the latter state log conductivity varies as 1/T.

ISSN:0003-6951    

DOI:10.1063/1.1654337

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

We have demonstrated an infrared singly resonant parametric oscillator using CdSe as the nonlinear crystal. The oscillator operates with either a resonant signal near 2.2 &mgr; or resonant idler in the 9.8‐ to 10.4‐&mgr; region. Using aQ‐switched Nd : YAG laser operating at 1.833 &mgr; as a pump source, we have observed thresholds of 550 W and up to 40% conversion efficiency. The angle‐tuned oscillator operates at room temperature with a 2‐cm−1bandwidth.

ISSN:0003-6951    

DOI:10.1063/1.1654338

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

A poled single crystal of LiNbO3doped with Rh as a new impurity is described in terms of its storage performance in producing high‐efficiency simple phase holograms. Doping with Rh introduces a new absorption band peaking around 4880 Å, and dramatically improves the recording sensitivity, diffraction efficiency, erasing sensitivity, and persistence of holograms over the undoped crystal. Anomalous optical erasure, possibly due to self‐enhancement of the hologram, is also observed in our doped crystal.

ISSN:0003-6951    

DOI:10.1063/1.1654339

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

A photoexcitation technique for the direct measurement of metal‐oxide‐semiconductor (MOS) flat‐band voltage is described. The principle consists of generating excess carriers in the semiconductor space‐charge region by infrared pulses as a function of potential applied across the MOS capacitor and utilizing the fact that the current pulses induced in the external circuit become identically zero when the applied voltage is equal to the flat‐band voltage. Experimental results are presented for MOS on silicon substrates.

ISSN:0003-6951    

DOI:10.1063/1.1654340

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

High concentrations of photocarriers have been produced in the bulk of a thin film of the photoconducting polymer poly‐N‐vinylcarbazole : trinitrofluorenone (PKV : TNF) by aQ‐switched ruby laser, and the bulk (bimolecular) recombination of the charge carriers has been observed. The kinetics of recombination are in quantitative agreement with a theory originally developed by Langevin for the diffusion‐controlled recombination of ions in high‐pressure gases. The recombination rate constant is proportional to the carrier mobility, and despite the low carrier mobility the rate constant is as large as is found in many semiconductors.

ISSN:0003-6951    

DOI:10.1063/1.1654341

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Vacuum ultraviolet (VUV) emission characteristics of xenon for pressures from 15 to 450 psi are presented. Stimulated emission was observed above 200 psi. Experiments were run both with and without mirrors. Without mirrors, the emission was 150 Å wide centered at 1700 Å, and the mean radiative lifetime was 2×10−8. The energy conversion efficiency was ∼ 20%. With mirrors above 200 psi the emission width narrowed to 17 Å centered at 1716 Å, and the output was highly directional. The pulse width narrowed from 50 to ∼ 3 nsec.

ISSN:0003-6951    

DOI:10.1063/1.1654342

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Rare‐earth doped crystals of lanthanum oxysulfide were found to exhibit strong photoconductivity which increases rapidly with temperature. Correlation of photoconductivity to luminescence spectra of La2O2S : Eu shows that thermal quenching of the luminous emission from5Dstates leads to the production of photocarriers, the majority of which are most likely holes. Special features of La2O2S : Eu photoconductivity indicate the important role which the charge‐transfer states play in the luminescence mechanisms.

ISSN:0003-6951    

DOI:10.1063/1.1654343

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

We have observed cw laser oscillation on ten transitions of singly ionized iodine in a He&sngbnd;I2mixture using a multiple anode‐hollow cathode laser tube of metal construction. Output characteristics as a function of helium pressure, iodine partial pressure, and discharge current have been investigated.

ISSN:0003-6951    

DOI:10.1063/1.1654344

出版商:AIP    

年代:1972

数据来源: AIP