摘要:

We derive an exact solution including pump depletion of collinear four‐wave mixing in a birefringent Kerr medium. We find mirrorless optical multistability for a linearly polarized backscattered signal with orthogonal pumps at cw power levels using a few meters of polarization‐maintaining silica fiber. An expression for the nonlinear phase distortion of ideal phase conjugation is obtained, showing a fundamental limitation to generating time‐reversed wave fronts using Kerr nonlinearity.

ISSN:0003-6951    

DOI:10.1063/1.98345

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

The first coupled‐stripe laser diodes fabricated by a laser‐assisted process are reported. In this process, a focused laser beam is scanned across AlGaAs‐GaAs heterostructure material to pattern a shallow resistive region in the GaAs cap layer. In this manner, the distribution of the injected current is patterned to fabricate gain‐guided four‐stripe diode lasers. The devices operate continuously (cw) at room temperature with a low threshold current (36 mA) and high differential quantum efficiency (80%). A maximum cw power efficiency of 48% is obtained at 350 mA. The gain‐guided structure favors the lower order array modes, thus the far‐field pattern is dominated by a central lobe.

ISSN:0003-6951    

DOI:10.1063/1.98346

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Induced‐absorption optical bistability has been studied in GaAlAs heterostructure rib and slab waveguides. Both whole‐sample and localized switching have been observed within the same device. The localized switch, which occurs on the time scale of a few microseconds and at an input power of 10–20 mW, has been induced using a laser‐diode source.

ISSN:0003-6951    

DOI:10.1063/1.98347

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Optical pumping of a holmium:yttrium lithium fluoride (Ho:YLF) crystal with a 790‐nm continuous‐wave diode‐laser array has generated 56 mW of 2.1 &mgr;m laser radiation with an optical‐to‐optical conversion slope efficiency of 33% while the crystal temperature is held at 77 K. The lasing threshold occurs at 7 mW of input power, and laser operation continues up to a crystal temperature of 124 K.

ISSN:0003-6951    

DOI:10.1063/1.98348

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Negative lithium ions, generated by volume processes, have been extracted from a small magnetically filtered multicusp ion source. Current densities of 1.9 mA/cm2have been obtained with a discharge voltage of 40 V and a discharge current of 4 A.

ISSN:0003-6951    

DOI:10.1063/1.98349

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Deflections of a He‐Ne laser beam in excimer and CO2laser‐produced plumes from Kapton films were measured. They show that in addition to the existence of a shock wave observed earlier, a slower cooling wave is also developed. A model calculation is presented which explains the present experimental data as well as previous results regarding the decrease of etching efficiency with increasing ambient gas pressure.

ISSN:0003-6951    

DOI:10.1063/1.98350

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Formation of silicides in the presence of a thin gold interlayer is studied, making use of the rapid outdiffusion of Si through gold. With Si being the dominant diffusing species, an enhanced rate is expected, as observed for PtSi, Fe3Si, CoSi, and MoSi2. No enhancement is expected when metal is the dominant diffusing species, in agreement with the results on Pt2Si, Co2Si, and Ni2Si. Such studies thus provide valuable information regarding reaction mechanisms.

ISSN:0003-6951    

DOI:10.1063/1.98351

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

We report the observation of resonant tunneling effects at high applied fields in the reverse‐bias current‐voltage characteristic of multiple quantum wellp‐i‐ndiodes. The Al0.48In0.52As/Ga0.47In0.53As structure (grown by molecular beam epitaxy with 35 periods of 139 A˚ barriers and 139 A˚ wells) shows two steps in the dark current. These are associated with Zener tunneling of electrons across the band gap from the lowest subband in the valence‐band quantum wells to the first and second subbands of adjacent conduction‐band wells.

ISSN:0003-6951    

DOI:10.1063/1.98352

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Application of moderate electric fields to ZnSe/(Zn,Mn)Se quantum wells yields distinct spectral shifts of the recombining exciton luminescence. This shows that confinement effects in this heterostructure are sufficient to increase the exciton ionization threshold. At high applied fields and low temperatures, injection of hot electrons from then+GaAs/ZnSe heterojunction at our substrate/buffer layer excites yellow luminescence from internal transitions of the Mn ion in (Zn,Mn)Se layers.

ISSN:0003-6951    

DOI:10.1063/1.98353

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Transmission electron microscopy and carrier concentration measurements are used to characterize the layer interdiffusion (Al‐Ga interdiffusion) mechanism of a Se‐doped AlxGa1−xAs‐GaAs superlattice (SL) under high‐temperature annealing. By varying the annealing environment and comparing the results with similarly annealed undoped SL’s and Mg‐doped SL’s, we find that the layer interdiffusion occurs through interaction of the Se impurity with native defects associated with As‐rich conditions, the most likely of which is the column III vacancy.

ISSN:0003-6951    

DOI:10.1063/1.98354

出版商:AIP    

年代:1987

数据来源: AIP