摘要:

Simple, self‐aligned phase‐coupled laser arrays consisting of ten 3‐&mgr;m‐wide stripes are described. The current flow was confined to the stripes by a Schottky barrier over the remainder of the laser chip. This process, applied to the AlGaAs graded‐index structures grown by metalorganic vapor phase epitaxy, produced arrays with threshold currents as low as 20 mA/stripe. The devices are capable of output powers of up to 1 W/facet and operate at temperatures as high as 100 °C with a stable far‐field pattern. In addition, novel information on the phase coupling in these gain‐guided arrays has been obtained.

ISSN:0003-6951    

DOI:10.1063/1.94822

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

We describe the characteristics of graded‐index separate‐confinement heterostructure (GRIN‐SCH) quantum well laser structures for a wide range of quantum well thickness and graded layer composition. It was deduced that the ‘‘GRIN’’ region enhances carrier confinement and assists the thermalization of carriers into the quantum well. A maximum value ofT0of 190 K was measured for these single quantum well lasers.

ISSN:0003-6951    

DOI:10.1063/1.94823

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

The operation of a new type of tunable laser, where the two separately controlled individual lasers are placed vertically in parallel, has been demonstrated. One of the cavities (‘‘control’’ cavity) is operated below threshold and assists the longitudinal mode selection and tuning of the other laser. With a minor modification, the same device can operate as an independent two‐wavelength laser source.

ISSN:0003-6951    

DOI:10.1063/1.94824

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

We have measured the statistical distributions of intensity fluctuations in an external cavity semiconductor laser. The cavity was formed by coupling a 6.8‐cm‐long multimode fiber to an antireflection coated, 10‐&mgr;m‐wide InGaAsP ridge‐waveguide laser. The fluctuations of the intensity of the laser are small when the cavity is adjusted for single‐longitudinal‐mode operation.

ISSN:0003-6951    

DOI:10.1063/1.94825

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Nonlinearities or kinks in the light‐current characteristics of channeled substrate buried heterostructure lasers are associated with higher order transverse mode transition and lateral mode movement. The active area has been reduced to stabilize the transverse mode. Fundamental mode operation up to high powers (24 mW/facet) has been obtained in devices with threshold current as low as 15 mA. Measurements and calculations are presented which show that nonlinearities occur at higher output power in lasers with reduced active area.

ISSN:0003-6951    

DOI:10.1063/1.94826

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

A Ti‐diffused lithium niobate, traveling wave modulator has been fabricated and tested at microwave frequencies. A Mach–Zehnder interferometer optical configuration and a coplanar waveguide electrical transmission line are used. For a 4‐mm interaction length, the modulator has a 3‐dB bandwidth of 13 GHz and requires only 2 V to switch at &lgr;=840 nm. The frequency response is measured directly using an ultrahigh speed photodiode, and the test setup therefore constitutes the highest bandwidth efficient electro‐optical transmission system ever reported.

ISSN:0003-6951    

DOI:10.1063/1.94806

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

An exact, analytic solution has been found for the coupled, nonlinear differential equations which describe the amplification of mode intensities for propagation through a homogeneously broadened amplifier with negligible population in the lower level. It is shown in this letter that the predictions of an analytic laser model based on the solutions to these equations can be scaled in a straight forward and easy manner to include the effects of a constant, lower level population.

ISSN:0003-6951    

DOI:10.1063/1.94807

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Raman scattering spectra for fluorine‐doped silica fibers are measured. A Raman scattering peak, assigned to be the Si–F bond in the fibers, is observed at a wave number of 930 cm−1. Heat tests in a hydrogen gas atmosphere are carried out. The result shows that the fiber loss due to the hydroxyl group, which is produced by the heat test, decreases by fluorine doping. These phenomena show that the Si–O–Si bond defects are filled with doped fluorine atoms, and oxygen atoms positioned at the defects are exchanged by the fluorine atoms.

ISSN:0003-6951    

DOI:10.1063/1.94808

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

In CO2laser target interaction, the axial and lateral hot‐electron energy deposition profiles are determined fromK&agr;emission and compared with those inferred from hard x‐ray continuum spectra, in the same experimental conditions. The two approaches are complementary and give the same results provided that the continuum and theK&agr;are produced by a similar electron distribution.

ISSN:0003-6951    

DOI:10.1063/1.94809

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

We describe a face‐on x‐ray backlighting method that does not require a dedicated laser beam and a separate x‐ray source. This method is used to measure the lateral mass transfer characteristic of the Rayleigh–Taylor instability in ablatively accelerated, laser driven targets.

ISSN:0003-6951    

DOI:10.1063/1.94810

出版商:AIP    

年代:1984

数据来源: AIP