摘要:

We have observed the radiative recombination of electrons, attached to nitrogen pairs, with holes on neutral acceptors. The acceptor binding energies are found to be 102.5±1 meV for Cd, 70.1±1 meV for Zn, and 54.7±1 meV for C, 8.3 meV larger than previously accepted values. This result implies corresponding increases in the band gap and exciton binding energy, to 2.350±0.002 eV and 22±2 meV, respectively, at 2 K.

ISSN:0003-6951    

DOI:10.1063/1.89836

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The performance of a high‐repetition‐rate (kHz) Raman oscillator is described. The oscillator employs a new configuration in which the Raman medium is located inside the pumping laser, and the Stokes outputs and pumping laser share the same resonator. The Raman oscillator consists of lithium iodate pumped by the 1.08‐&mgr;m output of Nd : YAlO3. In separate experiments, we have generated 1.26 W of 1.18‐&mgr;m first Stokes average output power and 550 mW of 1.31‐&mgr;m second Stokes average power.

ISSN:0003-6951    

DOI:10.1063/1.89837

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

We have fabricated a new type of channel stripe laser with a curved active region which has a spatially stabilized output for measurements up to 2ITh(Pout=75 mW/facet). The CJSF laser has excellent lateral and longitudinal mode selectivity. The laser operates in almost single longitudinal mode when the current exceeds 1.1ITh. Zeroth‐order lateral mode operation is obtained for currents less than 1.5ITh(Pout=30 mW/facet) and linear power output for measurements up to 2ITh. We attribute the favorable characteristics to the curvature of the grown layers which leads to the stabilization of the lateral modes.

ISSN:0003-6951    

DOI:10.1063/1.89838

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

A low‐temperature plasma oxidation of GaAs (lower than 100 °C) has been realized. The oxidation apparatus mainly consists of a quartz tube chamber, a low‐power rf oscillator and an electrical magnet. The oxidation rate can be controlled in the range 100–600 A˚/min by changing the magnetic field perpendicularly applied to the sample. The interface state density betweenp‐type GaAs and its oxide film is the order of 1010cm−2 eV−1around 0.5 eV from the top of the valence band. This low state density suggests that the oxide film can be applied to various GaAs MOS devices. For the oxide film ofn‐type GaAs, an anomalous frequency dispersion in the MOS capacitance is found in the accumulation region. This anomaly is very similar to that observed in anodic oxidation.

ISSN:0003-6951    

DOI:10.1063/1.89839

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Oxide films up to 2500 A˚ thick have been grown by anodization of GaAs in the negative glow region of a dc oxygen discharge. Using Auger analysis, as‐grown samples were found to contain excess Ga in the bulk of the film and excess As in a wide oxide‐GaAs interface region. Preliminary measurements indicate that plasma anodic films grown on bothp‐ andn‐type GaAs exhibit electrical properties similar to films formed by liquid anodization.

ISSN:0003-6951    

DOI:10.1063/1.89841

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Stable room‐temperature light emission has been observed from planar Mg‐MgO‐Ag junctions. The light emission is presumably due to roughness‐induced radative decay of surface plasma modes excited by tunneling electrons. Roughening of the planar tunnel structure is obtained by growth of a plateletlike structure during slow evaporation of the Mg film.

ISSN:0003-6951    

DOI:10.1063/1.89842

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The lateral‐collection photodiode (LCP) is a novel device in which thep‐njunction of a conventional photodiode is replaced by a matrix of smallp‐njunctions that collect photogenerated minority carriers from the intervening region. The LCP offers reduced capacitance and, in some cases, increased detectivity. IV‐VI semiconductor LCP’s for the 3–5‐&mgr;m spectral region show a capacitance reduction by up to a factor of 20 and a Johnson‐noise‐limited detectivity increase by up to a factor of 3 relative to a conventional photodiode in the same material.

ISSN:0003-6951    

DOI:10.1063/1.89817

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Energy stored in a superconducting resonator has been switched to an external load producing a pulse of microwave power. The peak power in the pulse was nine times that of the source feeding the cavity, and the pulse was observed to be phase locked to the source.

ISSN:0003-6951    

DOI:10.1063/1.89843

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Preliminary measurements on a (quasi‐) degenerate parametric amplifier using a single Josephson tunnel junction as the active element is reported. The pump frequency is at 18 GHz and the signal and idler frequencies are both at about 9 GHz. A power gain of 16 dB in a 4‐MHz 3‐dB bandwidth is achieved at the top of the cryostat.

ISSN:0003-6951    

DOI:10.1063/1.89844

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The flux‐flow critical current as a function of transverse magnetic field for an oxygen‐doped Al film perforated with a two‐dimensional triangular lattice pattern of holes shows pronounced structure at harmonically related values of the applied magnetic field. Effects at thecharacteristic fields are interpreted in terms of the interaction between commensurate flux‐line sublattices, one of which is strongly pinned to the holes by the vortex‐hole coupling force and the other of which is located interstitially between the hole‐lattice sites. A model is proposed for the vortex‐hole coupling force which, in conjunction with a treatment of vortex‐vortex interactions, qualitatively accounts for the observed temperature and field dependence of these harmonically related critical currents.

ISSN:0003-6951    

DOI:10.1063/1.89845

出版商:AIP    

年代:1978

数据来源: AIP