摘要:

We report the generation of difference‐frequency acoustic surface waves by the nonlinear interaction of intersecting noncollinear surface‐wave beams on [111]‐cut bismuth germanium oxide, a material of suitable anisotropy. The wave vector of the mixed‐frequency beam can be steered over a range of angles by varying the frequency ratio of the input beams. Agreement with a coupled‐mode theory is found. It is pointed out that the effect makes a number of new surface‐wave devices possible.

ISSN:0003-6951    

DOI:10.1063/1.1654396

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Planar optical waveguides have been made by sealed ampoule diffusion of Cd and Se into ZnS and Cd into ZnSe. Three‐dimensional diffused guides of Cd‐diffused ZnSe have been made by using a masking layer of evaporated oxidized SiO, which was shadowed with silica or glass fibers or copper wire. Structures 50 and 160 &mgr;m wide and 10 &mgr;m deep with severely etched surfaces yielded losses of 10 dB/cm. Suppression of thermal etching in small‐index‐gradient guides 10 &mgr;m wide by 3 &mgr;m deep gave losses of less than 3 dB/cm.

ISSN:0003-6951    

DOI:10.1063/1.1654397

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

ZnO optical waveguides have been found to withstand power fluxes up to 1011W/cm2in pico‐second pulses before damage occurred. Under the high power, a TE0mode at 1.06 &mgr;m generated a TM1mode at 0.53 &mgr;m. A ray theory of second‐harmonic generation in waveguides has been developed and the experimental results are compared with it.

ISSN:0003-6951    

DOI:10.1063/1.1654398

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Ions are implanted into a Si&sngbnd;SiO2interface. If the distribution is several hundred angstroms wide, the ions create interface states at energies corresponding to their bulk levels. With most elements investigated, agreement with previous data is good. Energy levels of the elements Se, Be, Cd, Sn, Ti, Pb, S, C, Ba, Ta, V, Mn, Cs, and Ge were determined by the MOS technique.

ISSN:0003-6951    

DOI:10.1063/1.1654399

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

The importance of applying the pulsed Redfield technique in the direct determination of the Hall mobility &mgr;Hof photocarriers in ferromagnetic semiconductors is exemplified, for the first time, by using pure EuO crystals. The value of &mgr;His obtained directly from the measurement of the Hall angle &thgr; = &mgr;HB/c, whereBis the magnetic induction andcis the light velocity. Thus, it is shown that a large negative‐magnetoresistance effect in undoped EuO crystals near the Curie temperatureTccan be attributed mainly to the mobility change. The photocarriers are identified to be electrons, and a mobility value as high as 250 cm2/V sec is observed at 26 °K.

ISSN:0003-6951    

DOI:10.1063/1.1654400

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

In vacuo photoemission from SiO2‐covered Si shows that the quantum yield and the energy threshold depend on the SiO2layer in the 10‐ to 120‐Å thickness range. These effects have been explained by electron‐optical phonon scattering in the thin SiO2layer before one Si‐emitted electron escapes into the vacuum. An approximate value of the phonon energy at the center of the Brillouin zone (&Dgr;E= 83 meV) and a mean free path for phonon scattering (l= 35 Å) are given.

ISSN:0003-6951    

DOI:10.1063/1.1654401

出版商:AIP    

年代:1972

数据来源: AIP