摘要:

A new transverse‐mode‐controlled laser called a buried multiquantum‐well (BMQW) laser has been developed. In order to make it possible to bury the MQW laser active region utilizing the diffusion‐induced disordering (DID) of GaAs‐GaAlAs MQW, zinc was selectively diffused into the MQW structure, resulting in a 3–8‐&mgr;m‐wide stripe region. The threshold current is as low as 33 mA with a 300‐&mgr;m cavity length and a fundamental transverse mode can be achieved. As a result of studying the relation of the waveguide geometry to the longitudinal and transverse modes it was concluded that this BMQW laser made by a simple DID process acts as an index‐guided laser.

ISSN:0003-6951    

DOI:10.1063/1.94988

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

A new x‐ray lithographic technique using no thin‐film pattern masks is presented. A pattern image is projected by utilizing the total reflection of the x ray from a pattern plate, in which a pattern picture is drawn on a thick and hard substrate. The projected image is geometrically demagnified by the sine of incident angle of the x ray. And we actually succeeded in obtaining the demagnified line and space patterns of 1.9‐&mgr;m width from the similar patterns of 210 &mgr;m by using copperK&agr;x ray.

ISSN:0003-6951    

DOI:10.1063/1.94997

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

cw operation of a chemical oxygen‐iodine laser (COIL) using ICl as a source of atomic iodine at powers approaching 120 W is reported. The vapor pressure of ICl is higher than the vapor pressure of the more conventional I2fuel usually used in COIL. More iodine can therefore be delivered to the laser gas stream using ICl than can be delivered using I2. This concentration increase is advantageous for low‐temperature operation at high partial pressures of the atomic iodine source.

ISSN:0003-6951    

DOI:10.1063/1.95010

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

We demonstrate a novel technique for estimating carrier leakage current in double heterostructure lasers. This utilizes the dependence of the carrier leakage motion on the high magnetic field directions. The carrier leakage current near threshold in GaInAsP‐InP lasers is estimated as a function of temperature from −25 to 65 °C. The result indicates that theT0value is improved from 58 to about 77 °C by suppressing the leakage current.

ISSN:0003-6951    

DOI:10.1063/1.94976

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

The radiation produced by focusing an intense CO2laser pulse on a tungsten target under vacuum was used for the direct dry photoetching of Kapton films. Typical etch rates of about 0.5 &mgr;m/pulse and surface smoothness with nonuniformities of the order of 1 &mgr;m were obtained by the simultaneous focusing of radiation on the Kapton target from the laser produced plasma (∼1.5 J/cm2) and the 10.6‐&mgr;m scattered laser radiation (∼23 J/cm2). In contrast, no etching whatsoever was observed when the Kapton film was irradiated by each of the two sources separately (by the use of LiF and ZnSe filters) under the same experimental conditions. It is suggested that in the present experiment the extra energy absorbed by the Kapton film from the CO2laser enables ablation of the UV sensitized layer close to the film’s surface.

ISSN:0003-6951    

DOI:10.1063/1.95005

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

We report a new type of optoelectronic device, a self‐electro‐optic effect device (SEED), which uses the same GaAs/GaAlAs multiple quantum well material simultaneously as an optical detector and modulator. Using a series resistor and constant voltage bias supply the SEED shows optical bistabilty (OB) of the recently discovered type which relies on increasing absorption and requires no mirrors. OB is seen at room temperature from ∼850–860 nm, at powers as low as 670 nW or switching times as short as 400 ns (limited only by power restrictions) with ∼1‐nJ optical switching energy in a 600‐&mgr;m‐diam device. Total energies per unit area (∼18 fJ/&mgr;m2) are substantially lower than any previously reported for OB.

ISSN:0003-6951    

DOI:10.1063/1.94985

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

GaAs‐AlGaAs multiple quantum well (MQW) injection lasers with well widths from 55 to 13 A˚ have been grown by molecular beam epitaxy and operated at room temperature, showing emission at wavelengths down to 704 nm, the shortest reported for a MQW injection laser with GaAs wells. In a device with 25‐A˚ wells some evidence of coupling was apparent when barrier widths were reduced to 40 A˚. For devices with 80‐A˚ barriers there is a difference of about 20 nm between the calculatedn=1 (e–hh) transition wavelength and the lasing wavelength, whereas the calculation agrees with photovoltage absorption measurements on the same structures.

ISSN:0003-6951    

DOI:10.1063/1.94986

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Coupled optical waveguide systems that transform coherent excitations ofNwaveguides into an excitation in a single waveguide are proposed. Such waveguide systems coupled to coherent laser diode arrays could function to combine the power from the individual laser elements to produce a single spot.

ISSN:0003-6951    

DOI:10.1063/1.94987

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

The pulsating elastic spherical shell is investigated in detail. A possible equivalent circuit is shown to contain two capacitors, two inductors, a transmission line, and an ideal transformer.

ISSN:0003-6951    

DOI:10.1063/1.94989

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Measurements of normalized radial emission coefficients in a free‐burning arc in argon are presented as a function of position in the arc. The variation of these emission coefficients with pressure indicates departures from local thermodynamic equilibrium at 1‐atm pressure.

ISSN:0003-6951    

DOI:10.1063/1.94990

出版商:AIP    

年代:1984

数据来源: AIP