摘要:

Phase‐matched second‐harmonic generation (SHG) was obtained in the visible spectrum by using the nonlinear waveguide. The guide consisted of quartz as the cladding and glass film as the waveguiding section.y‐cut quartz was used for the nonlinear medium. AQ‐switched YAG laser was used as the pumping source. The guided modes of the pump were TE00and TM00, and that of the second harmonic (SH) was TM02. The phase‐matched thickness 2bof the glass film was 2.55 &mgr;m with an allowable tolerance of about 30 Å for an interaction length of 10 mm. The peak output power was 70 mW. The results were in agreement with theory.

ISSN:0003-6951    

DOI:10.1063/1.1654834

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

It is shown theoretically that stimulated vacuum ultraviolet emission at [inverted lazy s] 1700 Å is possible in the afterglow of a suitably prepared ionized xenon plasma. Our model involves the dissociative recombination ofXe2+as a key step in the kinetic scheme leading to the production of excitedXe2*dimers. It is found that the maximum value of the dimer population occurs for a plasma that is initially [inverted lazy s] 1% ionized with cold gas atoms. Both plasma heating and higher levels of ionization inhibit dimer formation. Excited state‐excited state loss channels are also seen to play an important role in limiting the peak dimer density. Comparison of this theory with recent experimental results involving relativistic electron‐beam‐excited plasmas is good.

ISSN:0003-6951    

DOI:10.1063/1.1654835

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Theoretical calculations supported by numerical simulations show that utilization of the nonlinear dependence of the index of refraction on intensity makes possible the transmission of picosecond optical pulses without distortion in dielectric fiber waveguides with group velocity dispersion. In the case of anomalous dispersion (∂2&ohgr;/∂k2>0) discussed here [the case of normal dispersion (∂2&ohgr;/∂k2<0) will be discussed in a succeeding letter], the stationary pulse is a ``bright'' pulse, or envelope soliton. For a typical glass fiber guide, the balancing power required to produce a stationary 1‐ps pulse is approximately 1 W. Numerical simulations show that above a certain threshold power level such pulses are stable under the influence of small perturbations, large perturbations, white noise, or absorption.

ISSN:0003-6951    

DOI:10.1063/1.1654836

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Holograms have been recorded on an photoconductor‐thermoplastic device at 1.15 &mgr;m. Diffraction efficiencies of 1–5% were obtained with exposures of 400–800 mJ/cm2. Holograms were formedin situwith rapid processing and at spatial frequencies as high as 1000 lines/mm.

ISSN:0003-6951    

DOI:10.1063/1.1654837

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

This letter shows that strain is a controlling factor in the rapid degradation of GaAs double‐heterostructure junction lasers. A birefringence study of these lasers reveals extensive strain fields introduced during the bonding procedure resulting from the different thermal‐expansion coefficients of the materials involved. A new bonding procedure was developed which does not introduce significant strains. Lasers fabricated with the old and new bonding procedures were subjectively categorized as low, moderate, or high strained. A direct correlation was measured between low‐strain and room‐temperature cw laser lifetime. Lasers fabricated with the new bonding procedure have operated cw for as long as 880 h.

ISSN:0003-6951    

DOI:10.1063/1.1654838

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

A method is proposed for the determination of deep impurity levels and density profiles fromC&sngbnd;Vmeasurements and is demonstrated on GaAs Schottky barrier diodes. The technique involves measurements of the time dependence of the bias voltage instead of the barrier capacitance. The spatial distribution of a deep level is observed to exhibit a peak at the boundary between an epitaxial layer and the semi‐insulating substrate. This deep center is located 0.8 eV below the conduction band.

ISSN:0003-6951    

DOI:10.1063/1.1654839

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Direct observation of back tunneling in MNOS requires the direct and continuous display of the charge previously injected into the insulator. A new experimental technique having such a feature is presented. It is characterized by its simultaneous and direct measurements of both the change in charge in the insulator and the corresponding change in the device's flat‐band voltage. Charge loss via back tunneling in devices of different tunnel‐oxide thicknesses is presented.

ISSN:0003-6951    

DOI:10.1063/1.1654840

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Surface corrugations with a period of 1108 Å and a depth of [inverted lazy s] 500 Å have been fabricated in glass. These corrugations were first produced in a photoresist film on glass by the optical interference of two 3250‐Å laser beams. The corrugation was transferred to the glass by ion beam etching.

ISSN:0003-6951    

DOI:10.1063/1.1654841

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Frequency locking of the cw dye laser to atomic absorption lines in helium and sodium gas discharges is reported. The mechanism for locking is attributed to a lens formed by the radial variation of index of refraction in the positive column.

ISSN:0003-6951    

DOI:10.1063/1.1654842

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

The performance of a transversely excited atmospheric‐pressure TEA CO laser under cryogenic conditions is discussed. With the addition of large amounts of helium as a buffer gas, an output energy of 35 mJ was attained. This energy output represents a considerable increase over that previously reported for a similar system.

ISSN:0003-6951    

DOI:10.1063/1.1654843

出版商:AIP    

年代:1973

数据来源: AIP