摘要:

A magneto‐optical switch using a yttrium‐iron‐garnet crystal plate with phase matching films requiring a drive voltage of only 5V is demonstrated at 1.3 &mgr;m wavelength. Using a semihard magnetic material, we developed a bistable magneto‐optical switch which drives with a switching speed of 20 &mgr;s. An extinction ratio of 24 dB was obtained.

ISSN:0003-6951    

DOI:10.1063/1.92209

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

A new semiconductor current injection heterostructure laser, the double‐barrier double‐heterostructure (DBDH) laser, is fabricated by incorporating a pair of very thin (250–450 A˚) unidirectionally graded barriers of very wide band gaps (≳ 2.00 eV) between the active layer and the uniform cladding layers of the conventional double‐heterostructure laser. As a result, the beam divergence of this new heterostructure laser can be independently varied by changing the AlAs composition of the uniform cladding layers without affecting the temperature stability of the thresholdIth, the external differential quantum efficiency &eegr;D, and possibly the reliability of the laser. With these lasers, excellent temperature stability ofIth, &eegr;Dspontaneous emission level, and abrupt transition from a light‐emitting diode mode to laser mode were achieved and maintained up to temperatures as high as 276 °C. Narrow beam divergence ∼ 26° and lowIth∼1 kA/cm2were also obtained simultaneously from the same lasers. The present DBDH laser wafers were grown by molecular beam epitaxy.

ISSN:0003-6951    

DOI:10.1063/1.92210

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

The semiclassical equations of a three‐level laser system are considered in this work. By applying the rotating wave approximations, a new simplified set of space‐averaged, but time‐dependent equations were obtained. The equations were found to be reliable for a finite polarization decay constant and in the range of weak and intermediate pumping intensities (pulsed) not larger than 1011sec−1.

ISSN:0003-6951    

DOI:10.1063/1.92211

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

The structural and optical properties of multiquantum‐well (MQW) structures grown by molecular beam epitaxy are strongly dependent on the substrate temperatureTsduring the growth. A study of the optimization of MQW structures as a function ofTsis carried out using optical and electron microscopy and photoluminescence characterization. Optimal temperatures in the range 670–730 °C are shown to yield smooth free surfaces and interfaces and high quantum efficiencies.

ISSN:0003-6951    

DOI:10.1063/1.92212

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Losses have been measured at 257.2 nm ine‐beam‐pumped, KrF laser mixtures at pump rates up to 4 MW/cm3and pressures up to 3000 Torr. A maximum absorption of 3.5% cm−1is observed in a gas mixture of 4‐Torr F2, 125‐Torr Kr, and 2871‐Torr Ar. Losses are reduced in the presence of lasing. The absorption cross section of Kr2F* at 257.2 nm is estimated to be 1.8(±1.1)×10−17cm2. Net gain has been measured as a function of pump rate in a gas mixture of 4‐Torr F2, 125‐Torr Kr, and 1371‐Torr Ar. A net gain of 22% cm−1and a gain to nonsaturable loss ratio ∼20 have been observed.

ISSN:0003-6951    

DOI:10.1063/1.92213

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

A new stripe geometry for cw GaInAsP‐InP layers is presented. The laser consists of a stripe contact defined on the In0.53Ga0.47As cap layer of a conventional double heterostructure. It is surrounded by two lateral‐reverse‐biased Schottky diodes fabricated onto thep‐type confinement layer. These lasers have a threshold curent of 100 mA for 320‐&mgr;m‐long and 20‐&mgr;m‐wide stripes and operate in the zero‐order transverse mode.

ISSN:0003-6951    

DOI:10.1063/1.92214

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

The influence of external feedback on low‐frequency noise generation (100 Hz–10 kHz) in single longitudinal and transverse mode channel substrate planar laser diodes is reported. An increase in noise by as much as 60 dB was induced by external feedback as small as 0.04%. The induced intensity variations were observed to be sensitive to both phase and amplitude of the externally reflected light.

ISSN:0003-6951    

DOI:10.1063/1.92215

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

The first study of a pulsed, far‐infrared, ring laser is described. Unidirectional, traveling‐wave operation is observed, thereby eliminating the spatial hole burning effects present in linear cavities. Single‐mode output powers of 100 kW have been obtained.

ISSN:0003-6951    

DOI:10.1063/1.92195

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Axially symmetrical vibrations of thick circular disk resonators made of polarized piezoelectric ceramic material excited by electrodes on the faces of the disk are calculated from the linear constitutive equations of a piezoelectric solid and the pertinent elastic and electrical boundary conditions using Hamilton’s variational principle and the boundary method of Trefftz. Good agreement with speckle heterodyne interferometric measurements of the waveforms is obtained.

ISSN:0003-6951    

DOI:10.1063/1.92196

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Plate mode expansions are used to evaluate the reflection, transmission, and bulk conversion of Rayleigh waves incident on the end of an isotropic plate of variable thickness.

ISSN:0003-6951    

DOI:10.1063/1.92197

出版商:AIP    

年代:1981

数据来源: AIP