摘要:

A novel surface‐emitting laser with a transverse junction stripe (TJS) and a folded‐cavity configuration, which has an internal 45° mirror facet to direct the light normal to the surface, has been achieved for the first time. The fabrication of the 45° mirror facet was carried out using a simple angled reactive ion etching technique, and the laser performance yielded a threshold current of 31 mA and an external differential quantum efficiency of 24% per facet, which are comparable to those of conventional TJS lasers.

ISSN:0003-6951    

DOI:10.1063/1.101702

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

Oil surface deformation on stripe electrodes by applying an electric field between neighboring electrodes is described. A laser beam can be diffracted by the deformed oil distribution on alternate electrodes. When the electrode width is 10 &mgr;m, the response times for voltageonandoffare 4 and 1 ms, respectively, and light scattering efficiency is more than 90%.

ISSN:0003-6951    

DOI:10.1063/1.101703

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

We demonstrate a high‐power AlGaAs single quantum well graded‐index separate confinement heterojunction laser grown by molecular epitaxy over channeled substrates. Fundamental mode operation up to 130 mW for reflection modified devices has been achieved at a high differential quantum front‐facet efficiency of 81%. This device structure allows extremely low threshold currents to 6 mA for power lasers due to the incorporation of lateral current blockingpnjunction by crystallographic plane‐dependent doping of amphoteric dopants. We obtained a very high‐power continuous‐wave fundamental mode operation of this type of laser at extremely low threshold currents and very high overall efficiency of more than 50%. This laser shows considerable potential for applications in optical storage and printer technology.

ISSN:0003-6951    

DOI:10.1063/1.101704

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

Utilizing the results of Cr3+→Tm3+transfer efficiency studies, we have demonstrated that YAG is the preferred host for the Cr:Tm:Ho laser, and that highest efficiencies are obtained at relatively low Cr3+concentrations. We have achieved a slope efficiency of 5.1% from a flashlamp‐pumped room‐temperature 2 &mgr;m laser.

ISSN:0003-6951    

DOI:10.1063/1.101705

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

Experimental observations are presented on the breakdown characteristics of a pseudospark discharge when a pulsed laser is used to illuminate the back surface of the cathode. The breakdown delay and jitter of the discharge are observed to be controlled by the laser. Observations are presented on the effect of the relative timing of the laser pulse with respect to the fast rising applied voltage. It is found that mJ illumination at up to tens of microseconds before the application of the voltage reduces significantly both delay to breakdown and jitter. High laser energy, applied after the voltage is established across the anode‐cathode region, leads directly to breakdown with a delay of less than 100 ns.

ISSN:0003-6951    

DOI:10.1063/1.101706

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

The desorption spectra of constant‐rate annealing of the plasma‐deposited amorphous hydrogenated silicon (a‐Si:H) films prepared from the SiH4/H2mixture gas show two peaks. The first peak is located at around 625 K and the position of the second peak varies from 765 to 903 K with the SiH4fraction in the SiH4/H2source gas. These experimental results seem to be strongly related to structural inhomogeneity of the plasma‐depositeda‐Si:H films. The change in the peak temperature of the high‐temperature evolution process is explained on the basis of the difference between the activation energy of the hydrogen evolution from the SiH centers and that from the SiH2center.

ISSN:0003-6951    

DOI:10.1063/1.101707

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

Diamond particles have been selectively synthesized on a SiO2dot‐patterned Si substrate using plasma‐assisted chemical vapor deposition (plasma CVD). Nucleation densities on both Si and SiO2have been increased, first by pretreatment using abrasive powders; then, to eliminate the pretreatment effect from almost all of the substrate and to retain the effect only at designed sites, an Ar beam is used to obliquely irradiate the pretreated substrate. After deposition using plasma CVD, diamond particles have selectively formed on one edge of the SiO2dots according to the pattern and have grown large to adjoin with adjacent particles. Polycrystals with equal grain sizes have been synthesized.

ISSN:0003-6951    

DOI:10.1063/1.101708

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

Scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS) have been used to study the epitaxy of CaF2on Si (111). Energy‐resolved images of the submonolayer structures produced at the initial stages of CaF2deposition were obtained. We found that in these structures and also at the 1×1 interface, bonding involves the Ca atom in a reduced, Ca+‐like state. Using STS we were able to measure the CaSi bonding‐antibonding level splitting at the interface. The distribution of charged defects was also imaged by the STM. More important, we found that we can image strongly insulating CaF2multilayers by tunneling into their conduction band.

ISSN:0003-6951    

DOI:10.1063/1.102457

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

Ionized cluster beam aluminum deposited on (100) silicon has a unique grain structure consisting of only two crystallographic orientations. Both are (110), but are rotated 90° with respect to each other about the (110) axis so that their (220) planes are perpendicular. This structure arises from a close match between the (200) planes in the aluminum and the (220) planes in the silicon along one direction, and the existence of a interfacial superlattice consisting of three (220) planes from the silicon and four (220) planes from the aluminum, along the orthogonal direction. This grain structure contains no triple points and curved grain boundaries.

ISSN:0003-6951    

DOI:10.1063/1.101709

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

We prepared a Cr‐Si‐O film by co‐sputter deposition and evaluated the properties with a view to applying to a strain gauge. It was found that the maximum gauge factor of 8.7 was obtained in the 200‐nm‐thick film at the composition of Cr‐1 at. % Si‐19 at. % O. In addition, the temperature coefficient of resistance of the film was 8 ppm/°C in the temperature range of 25–120 °C and the fractional change in resistance after annealing was less than ±0.1% up to 400 °C.

ISSN:0003-6951    

DOI:10.1063/1.101710

出版商:AIP    

年代:1989

数据来源: AIP