摘要:

Single crystals of KTiOAsO4, a material which is isostructural with the well‐known nonlinear optical material KTiOPO4(KTP), were grown by a flux process and its optical and dielectric properties characterized. Compared to KTP, KTiOAsO4has a higher figure of merit for second‐harmonic generation, larger electro‐optic coefficients, and lower ionic conductivity. As a result, KTiOAsO4should become a viable alternative for KTP.

ISSN:0003-6951    

DOI:10.1063/1.101552

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

The output energy (90 &mgr;J), focal spot diameter (235 &mgr;m), and pointing accuracy (±75 &mgr;rad) for a 3.7‐cm‐long Se soft x‐ray laser operating at 20.6 and 20.9 nm are reported. Now that this intense soft x‐ray source has been well characterized it may find use in such diverse applications as lithography, contact microscopy, holography, and photoionization pumping.

ISSN:0003-6951    

DOI:10.1063/1.101359

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

Sum frequency mixing in KTiOPO4of the 809 nm light from a GaAlAs laser diode and the 1064 nm light from a diode‐pumped Nd:YAG laser has been used to generate blue radiation at 459 nm. The specific problems associated with the use of high‐power multimode GaAlAs diode lasers as the source of the 809 nm mixing radiation were investigated in detail. Rapid modulation of the blue output and generation of 5 ns pulses by direct modulation of the GaAlAs laser diode were demonstrated.

ISSN:0003-6951    

DOI:10.1063/1.100847

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

Laser optogalvanic (LOG) signals at 667.7, 751.5, and 696.5 nm from the3P1and3P2levels of Ar were studied at a pressure of 250 mTorr in a rf glow discharge. Signals with unexpected signs and time dependences were found. The results are interpreted as being due to radiative trapping effects and collisional mixing between resonance and metastable levels. An average electron energy of 2.1 eV is derived from modeling the data.

ISSN:0003-6951    

DOI:10.1063/1.100848

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

Compositionally modulated thin films of Cu and Y were prepared in an ultrahigh vacuum dc ion beam deposition chamber. Room‐temperature growth of an amorphous Cu‐Y phase was observed with interdiffusion of the elemental Cu and Y. Transmission electron microscopy of as‐prepared samples revealed a novel growth morphology; amorphous phase formation was observed both at the original Cu/Y interface and between the grains of the elemental Y. Estimates for the thermodynamic and kinetic factors underlying the grain boundary amorphization reaction are presented.

ISSN:0003-6951    

DOI:10.1063/1.100849

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

Modeling of the diffusion of high‐concentration implanted B in Si is done. The normally accepted model, which assumes that diffusivity of boron is controlled by the singly charged donor vacancy, is shown to be inadequate in describing the boron profiles. Rather, a two‐stream model, in which boron movement is dominated by a dissociative process involving both interstitial and substitutional diffusion, is found to be in good agreement with the data.

ISSN:0003-6951    

DOI:10.1063/1.100850

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

A technique is described for measurement of lateral forces on a scanning tunneling microscopy (STM) tip simultaneously with surface topography, using optical sensing of the STM tip vibration. The STM tip is caused to vibrate near a resonant mode in the lateral direction, using the capacitive forces between the tip and the surface under study. Topography is monitored using thez‐displacement feedback voltage, in a low‐frequency loop, while optical sensing of the high‐frequency tip vibration amplitude monitors lateral forces acting on the tip.

ISSN:0003-6951    

DOI:10.1063/1.100851

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

Raman spectroscopy is used to characterize highly mismatched (7%) InAs‐AlAs superlattices grown by atomic layer molecular beam epitaxy. In particular, folded acoustic modes are presented and compared with two different theoretical models (Rytov and linear chain). We find good agreement between theory and experiments. We estimate, with a simple model, the magnitude of the effect of the strain on the phonon frequency shifts.

ISSN:0003-6951    

DOI:10.1063/1.100852

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

The characteristics of light soaking and equilibrium electron spin resonance (ESR) inp‐hydrogenated amorphous silicon‐carbon/i‐hydrogenated amorphous silicon heterojunction are investigated. The influence of the carbon content in theplayer on ESR is also studied in this letter. We find that the light‐induced silicon dangling bond defects mainly originate from theilayer and the increased spin density can be decayed by annealing at a low temperature (160 °C). Possible microscopic mechanisms of the light‐induced defects observed in thep/iheterojunction are discussed as well.

ISSN:0003-6951    

DOI:10.1063/1.100853

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

Time evolution of photoconductivity of semi‐insulated gallium arsenide illuminated at low temperatures with monochromatic 0.7–1.8 eV photons was studied. For low light intensity the photosensitivity increases with time by several orders of magnitude and exhibits different dynamics for above‐the‐gap and below‐the‐gap energy photons. For various photosensitivity stages the concentration of charge trapped in deep traps was determined by measuring thermally stimulated current. Six deep traps in the 85–250 K temperature range were observed. Good correlation between the photosensitivity and the total concentration of trapped charge was found. The increase of photosensitivity is interpreted as the increase of lifetime of optically created free holes due to the trapping of electrons, which therefore are not available for recombination. The same interpretation also gives a new insight in previously published results on increased photosensitivity in gallium arsenide.

ISSN:0003-6951    

DOI:10.1063/1.100854

出版商:AIP    

年代:1989

数据来源: AIP