摘要:

A novel method to achieve phase‐matched light amplification in a birefringent fiber via the three‐wave mixing is proposed by using frequency shift change due to the stress applied to the fiber. It is confirmed that the signal power from a cw laser diode at &lgr;=1.292 &mgr;m is amplified by 6.1×103times in the birefringent fiber pumped with aQ‐switched Nd: yttrium aluminum garnet laser at &lgr;=1.064 &mgr;m. This will provide a new fiber‐optic light signal amplifier having a good tolerance for variation of signal wavelengths.

ISSN:0003-6951    

DOI:10.1063/1.93418

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Burn‐off output powers of catastrophic failures have been studied for GaAlAs double heterostructure (DH) lasers with facet coatings in the wavelength range of 750–870 nm. It was found that the burn‐off power density does not depend on the lasing wavelength when the laser is operated under pulsed condition, whereas it decreases slightly as the wavelength becomes shorter under cw condition.

ISSN:0003-6951    

DOI:10.1063/1.93419

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Very low threshold InGaAsP terrace lasers on semi‐insulating (SI) InP substrate have been fabricated using the mass transport technique. The fabrication process involves a single‐step liquid phase epitaxial (LPE) growth followed by a mass transport of InP at ∼675 °C in the presence of an InP cover wafer. Lasers operating in the fundamental transverse mode with smooth far‐field patterns and threshold currents as low as 9.5 mA have been obtained.

ISSN:0003-6951    

DOI:10.1063/1.93420

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Mode discrimination and control in high‐power constricted double‐heterojunction large‐optical‐cavity (CDH‐LOC) lasers are determined by three factors: a sharp lateral variation in radiation confinement factor, a ‘‘built‐in’’ dielectricWguide in the plane of the junction, and the influence of gain‐induced index depressions on theWguide. Excellent far‐field pattern fits are achieved by using theactualgeometries and compositions of two high‐power CDH‐LOC structures, and gain‐induced (bulk) index depressions in the −0.02 to −0.03 range. The dependence of mode discrimination on the gain‐induced index depression allows tailoring CDH‐LOC devices for specific spatial mode operation.

ISSN:0003-6951    

DOI:10.1063/1.93421

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

A high power (200 mW/facet) phased array semiconductor injection laser consisting of multiple optically coupled 7700‐A˚ emitters is focused to obtain over 90 mW in a single nearly diffraction limited 2.5‐&mgr;m‐diam spot. Focusing is accomplished by imaging the vertical near‐field and the lateral far‐field patterns. Such an optical system functions only when the emitters are mutually coherent, as with this device.

ISSN:0003-6951    

DOI:10.1063/1.93422

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

A 50‐MHz acoustic microscope for imaging Rayleigh wave velocity perturbation over a surface is described. A line scan of a multiple‐thickness indium film deposited on a glass shows that the system has a potential sensitivity of 1 part in 105change in velocity.

ISSN:0003-6951    

DOI:10.1063/1.93423

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Thermal oxidation of TaSi2in dry oxygen and steam has been investigated. 0.3‐&mgr;m‐thick films of tantalum silicide were deposited by cosputtering on high resistivity ⟨111⟩ silicon and oxidized silicon wafers. After a crystallization anneal in argon, the films were oxidized in dry O2or steam at 1000 and 1100 °C. In all cases oxidation was observed. For TaSi2deposited on Si, only the growth of SiO2was observed, indicating that the Si diffused through TaSi2before oxidation, and TaSi2remained intact. In the case where TaSi2was deposited on SiO2, it was actively involved in the oxidation process, resulting in the formation of SiO2and Ta2O5.

ISSN:0003-6951    

DOI:10.1063/1.93424

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Correlation of resisitivity measurements with transmission electron microscopy analysis reveals that indium/indium oxide thin films, prepared by reactive ion‐beam sputter deposition, undergo pronounced and heretofore unrecognized structural phase transitions as a function of increasing oxide content. We have found that these films can be fabricated in a reproducible manner with microstructure characterized as either granular, with crystalline grains embedded in crystalline oxide, amorphous, or mixed amorphous and crystalline.

ISSN:0003-6951    

DOI:10.1063/1.93408

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Using a cleavage cross‐section technique in combination with Nomarski and scanning electron microscopy, the irradiation of silicon wafer backsides with neodymium: yttrium aluminum garnet laser pulses with energy densities of 20 J/cm is shown to lead to the formation of microcracks in the silicon up to a depth of 20–40 &mgr;m. The microcracks are shown to heal during a temperature cycle at 1050 °C. Preferentially etching the cleaved cross‐section surfaces shows the occurrence of dislocations, and the healing of the microcracks is suggested to be the mechanism for the formation of these dislocations, possibly in the form of low angle boundaries. The observed effects and interpretation offer an explanation for the wafer fracture strength behavior exhibited by laser backside damaged silicon wafers.

ISSN:0003-6951    

DOI:10.1063/1.93409

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Dark currents and photocurrents were measured in 3–6‐&mgr;m‐thick films of polyphenylacetylene (PPA) and of iodine‐doped PPA. In undoped PPA, Schottky–Richardson injection from the electrodes is observed and holes are strongly trapped. Defect states exert a major control over dark currents and photocurrents. The photoconductivity action spectrum shows a good response in the red at energies well below the absorption edge. We conclude that undoped PPA is capable of trap‐modulated electron transport through states in the band gap. Doping with iodine enhances photocurrents through charge transfer interaction.

ISSN:0003-6951    

DOI:10.1063/1.93410

出版商:AIP    

年代:1982

数据来源: AIP