摘要:

A single longitudinal mode optical pulse train with a full width at half maximum less than 7.2 ps was generated by compressing gain‐switched pulses from a 1.3 &mgr;m multimode laser diode using a monochromator and a dispersion‐shifted single‐mode optical fiber.

ISSN:0003-6951    

DOI:10.1063/1.102022

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

Spontaneous emission spectra from GaAs quantum well lasers grown by molecular beam epitaxy show that the radiative recombination rate in (AlAs)(GaAs) superlattice barriers is greater than in alloy barriers of the same average composition (x=0.25) due to reduction in effective gap by superlattice effects. Measurements of emission spectra as functions of temperature show that these radiative processes account for a significant part of the temperature variation of the threshold current and we estimate that the nonradiative lifetime in the superlattice barriers is an order of magnitude longer than in alloy barriers grown under similar conditions.

ISSN:0003-6951    

DOI:10.1063/1.102023

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

A wide tunable optical fiber ring laser with a diffraction grating as a tuning element is demonstrated. A wide tuning range over 100 nm is achieved using a high performance traveling‐wave amplifier (TWA) as a gain medium. The TWA with a V‐grooved inner stripe structure on apsubstrate (VIPS structure) has a high peak gain over 30 dB and a broad gain width of 100 nm at 16 dB. The effects of the gain of TWA and the total loss of the external ring cavity on the tuning range are also discussed.

ISSN:0003-6951    

DOI:10.1063/1.102024

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

The performance of a continuous wave actively mode‐locked Nd: phosphate glass laser longitudinally pumped by a multistripe diode laser is described. The laser operates at 1.054 &mgr;m; the pump threshold and the slope efficiency are found to be 120 mW and 11%, respectively. The shortest pulse duration is 7 ps, which appears to be approximately twice as short as predicted by the theory of amplitude modulation mode locking. We explain the improved performance by additional frequency modulation due to the nonlinear index of the active material.

ISSN:0003-6951    

DOI:10.1063/1.102025

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

A Si3N4core waveguide, matched to a laser mode, is adiabatically tapered into a SiO2:P core waveguide, matched to a fiber mode. When used to couple the light from a semiconductor laser into an optical fiber, a loss of 3.1 dB is obtained, compared to a loss of 4.5 dB obtained with a lensed fiber.

ISSN:0003-6951    

DOI:10.1063/1.102290

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

Recording of low spatial frequency gratings in iron‐doped LiNbO3crystals using a single write beam by both direct contact and optical projection methods is reported. Gratings with periods in the range 50–200 &mgr;m have been produced generating up to 40 visible diffraction orders when probed with a low‐power HeNe laser. Diffraction efficiencies over 20% are achieved for the first diffraction order.

ISSN:0003-6951    

DOI:10.1063/1.102289

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

The second‐harmonic generation of leaky waves at the interface between glass and iron has been investigated. Fundamental frequency interface waves are excited by bulk shear waves, incident at the critical angle, and the generated second‐harmonic surface waves are detected by reradiated bulk shear waves. The amplitudes of the generated second harmonic obey the square law. The second‐harmonic generation decreases sharply as the incident and detection drive deviate from the critical angle.

ISSN:0003-6951    

DOI:10.1063/1.102026

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

The rotational temperature of a nitrogen molecule (N2) was observed to increase proportionally with the substrate‐holder temperature in a capacitively coupled rf glow discharge system. The rotational temperature, equivalent to the gas temperature, from the second positive system of the emission spectrum of N2increased with increasing the mixing ratio of hydrogen, which correlates with the deposition rate, optical band gap, and etching rate of silicon nitride (SiNx). This technique can be used for monitoring the temperature of a SiNxsurface during glow discharge processing without any damage to the plasma.

ISSN:0003-6951    

DOI:10.1063/1.102291

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

A model for the thermal dependence of atomic flux in passivated Al/AlSi very large scale integrated interconnects is presented. The model is derived from stress‐induced alterations in the equilibrium vacancy concentration in the metal, and has an exponential form which can be interpreted as a temperature‐dependent activation energy. The flux model together with the thermal hysteresis of stress reported for thin films can be used to describe a wide range of voiding behavior.

ISSN:0003-6951    

DOI:10.1063/1.102027

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

A new technique for the reduction of the interface‐state densityNssof a metal‐oxide‐semiconductor (MOS) diode has been developed. The SiO2film was deposited on Si from Si2H6and O2by direct photochemical vapor deposition (CVD) using vacuum ultraviolet (VUV) light of a D2lamp. The new technique is a F2treatment of the Si surface prior to the deposition of SiO2film. Typically, 5% F2gas diluted in He was introduced into the CVD chamber at 20 Pa for 5 min under UV light irradiation. The minimum value of theNsswas ∼5×109cm−2 eV−1at the Si midgap for the film deposited at 180 °C.

ISSN:0003-6951    

DOI:10.1063/1.102292

出版商:AIP    

年代:1989

数据来源: AIP