摘要:

A novel micropolarizer has been fabricated from alumina and nickel by means of anodization and electroplating techniques. Making use of the anisotropic microstructure of the anodized alumina film, a lattice of nickel columns is easily constructed in the film, which works as a wire grid type polarizer. The fabricated polarizer has achieved an extinction ratio larger than 30 dB at the wavelength of 1.3 &mgr;m.

ISSN:0003-6951    

DOI:10.1063/1.101572

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

We have demonstrated an integrated magnetic field sensor consisting of a Faraday rotator and a mode selector for the first time. The sensor is a loaded waveguide which has a waveguide layer made of a garnet with magneto‐optical effect for Faraday rotation and a metal clad layer for mode selection. The magnetic field can be measured by detecting the change of optical output power from the waveguide. An output power change of ±5% has been observed as the magnetic field is changed from zero to ±60 Oe.

ISSN:0003-6951    

DOI:10.1063/1.101825

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

A new type of spatial light modulator has been demonstrated, operating by the surface plasmon resonance effect. Devices have been constructed using nematic liquid crystal as the active material, and the operation of these devices is 50 times faster than the bulk switching of the liquid‐crystal cells. We have obtained resolution of 10–20 &mgr;m and contrast ratios better than 100:1.

ISSN:0003-6951    

DOI:10.1063/1.101826

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

A simple measuring technique for the linear electro‐optic coefficients in electro‐optic waveguides is described. The method is based on the direct evaluation of synchronous angle measurements obtained by prism coupling. No waveguide or electrode patterning is required. A model has been developed in order to simulate the relation between change in synchronous angle and applied electric field across the electro‐optic waveguide. The measured values of the electro‐optic coefficients in poled polymer waveguides are reported.

ISSN:0003-6951    

DOI:10.1063/1.101827

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

Resistless microfabrication of the metallization ofn‐type GaAs formed by projection‐patterned doping using a KrF excimer laser is described. Silane (SiH4) gas is used as a source material of then‐type dopant of Si. Copper thin films with a linewidth as narrow as 3.4 &mgr;m are deposited selectively on the doped region by electroplating using a CuSO4aqueous solution. Using the selective metallization process, nonalloyed ohmic contacts can be formed with a specific contact resistance of 2.32×10−5&OHgr; cm2, which is one‐thirtieth of that of the conventional alloyed contacts.

ISSN:0003-6951    

DOI:10.1063/1.101828

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

The initial stages of molecular beam epitaxial (MBE) growth of GaAs and AlGaAs are directly observed by scanning reflection electron microscopy. Under deficient As4flux, it is shown that dark areas appear within several layers of growth, but disappear within several seconds of growth interruption, indicating that they are droplets of Ga and Al. The distance between the droplets is approximately 1 &mgr;m, which is identical in GaAs and AlGaAs growth. Thus, the diffusion length of Ga and Al on a group III‐rich surface at around 600 °C is estimated to be about 5000 A˚, which is the largest among previous reports. The role of droplet disappearance in interface flattening in alternating supply MBE is discussed.

ISSN:0003-6951    

DOI:10.1063/1.101829

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

We have devised and demonstrated a novel technique for fabricating structures with nanometer scale features in semiconductor heterostructures. The technique is based on definition of nanometer scale patterns by submicron trenches in a GaAs‐AlGaAs heterostructure. The depletion of free carriers below the trenches gives rise to very strong electrostatic confinement. This technique avoids the complications associated with the use of negative resist materials and lift‐off techniques while minimizing the time required to expose densely packed patterns. Aharonov–Bohm rings fabricated using this technique exhibit interference oscillation larger than any reported previously.

ISSN:0003-6951    

DOI:10.1063/1.101805

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

Nuclear magnetic resonance pulse techniques are appliedinsituto investigate the dynamics of mobile dislocations during creep deformation of NaCl single crystals.23Na spin‐lattice relaxation rates were measured in the rotating frame (T1&rgr;) during compression creep of single crystals of NaCl along the [110] direction at 478 K and 20 MPa. The relaxation rates are evaluated from the spin‐echo height following a &pgr;/2 locking and 64° pulse sequence. The mean jump distance of the mobile dislocations, evaluated from the ratio of the signal heights without deformation and during creep, decreased with time/strain reaching a constant value at the onset of the steady‐state creep regime. The results are compared with the dislocation‐dislocation spacing, the subgrain size, and the jump distance predicted from creep models.

ISSN:0003-6951    

DOI:10.1063/1.101806

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

Thin diamond films were deposited on silicon, MgO, fused silica, and soda lime silica glass at low temperature (the lowest temperature ∼365 °C) by microwave plasma‐enhanced chemical vapor deposition. The films were identified as diamond by Raman spectroscopy. A Raman peak shift of several wave numbers to either lower or higher wave numbers due to the strain of the film is also observed. The film deposited on glass is highly transparent. The fine faceted crystals in the film are shown in scanning electron microscope micrographs.

ISSN:0003-6951    

DOI:10.1063/1.101807

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

Observation of single‐crystal diamond growth in thin films obtained from the rf decomposition of a CH4/Ar plasma is reported. The films were deposited on Si substrates which were kept at 20 °C. Polycrystalline diamond grains are seen over the entire film. Single‐crystal diffraction patterns obtained from larger grains all show {111} twinning.

ISSN:0003-6951    

DOI:10.1063/1.101808

出版商:AIP    

年代:1989

数据来源: AIP