摘要:

Guided‐wave electro‐optic Mach–Zehnder interferometric modulators have been fabricated on LiNbO3. The channel waveguides were formed by titanium indiffusion in some devices and proton exchange in benzoic acid in others. The modulators were tested at 0.85‐&mgr;m and/or 1.3‐&mgr;m wavelengths for insertion loss, electro‐optic activity, and susceptibility to optical damage. A substantial reduction in the electro‐optic activity accompanied by a reduced susceptibility to optical damage is measured for the proton‐exchanged modulators.

ISSN:0003-6951    

DOI:10.1063/1.94280

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

The hot‐carrier effects reported for InGaAsP light‐emitting diodes are shown to result primarily from lattice heating. The small amount of heating observed at currents corresponding to typical threshold current density has negligible effect on the characteristic temperatureT0measured for InGaAsP lasers under pulsed conditions.

ISSN:0003-6951    

DOI:10.1063/1.94281

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

A phase‐locked array of InGaAsP lasers has been fabricated for the first time. This 50‐&mgr;m‐wide array utilized diffraction coupling between adjacent lasers to achieve phase locking. Threshold current as low as 200 mA is obtained for arrays with 250‐&mgr;m cavity length. Smooth single‐lobe far‐field patterns with beam divergence as narrow as 3° have been achieved.

ISSN:0003-6951    

DOI:10.1063/1.94282

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

Constricted double‐heterojunction diode lasers have been life tested at 70 °C heatsink temperature and 3–4 mW/facet in cw operation. A median life of 7800 h is obtained at 70 °C, which extrapolates to 4×105h median life at room temperature. The extrapolated mean time to failure at room temperature is in excess of 106h. Single‐longitudinal‐mode cw operation is maintained after 10 000 h of accelerated aging at 70 °C.

ISSN:0003-6951    

DOI:10.1063/1.94283

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

In this letter we consider the effect of fast thermal fluctuations of electronic state occupancy on the field spectrum of semiconductor lasers and derive for the first time an expression for the resulting power independent linewidth contribution. The magnitude and temperature dependence of this linewidth component agree reasonably well with measurements of a power independent linewidth made by Welford and Mooradian.

ISSN:0003-6951    

DOI:10.1063/1.94260

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

Laser‐induced fluorescence of sodium atoms seeded into a supersonic nitrogen jet is used to determine the velocity, temperature, and pressure of the flow. The visible signal is sufficiently intense for spatially resolved flow visualization purposes.

ISSN:0003-6951    

DOI:10.1063/1.94284

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

A new technique is described for high‐spatial‐resolution (<2‐&mgr;m linewidth) etching of Al thin films. The process is based upon moderate local heating by a tightly focused Ar+laser beam to activate an etching reaction in mixtures of phosphoric acid, nitric acid, and potassium dichromate. By chemically biasing the reaction near its passive/active transition, the laser can enhance the reaction rate by more than six orders of magnitude. The etching mechanism has been studied by etch‐rate measurements, ellipsometry, and Auger spectroscopy, and is ascribed to a competition between the formation of soluble aluminum phosphates and insoluble aluminum oxides.

ISSN:0003-6951    

DOI:10.1063/1.94285

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

A novel single mode optical fiber tapped delay line that uses silicon V‐groove substrates to align an array of directional coupler taps has been demonstrated as a transversal filter. The device was used to generate and correlate 4‐bit, 400‐Mb/s coded sequences. The generated codes exhibited an amplitude uniformity of ±0.04 dB. The electrical correlation output was linear over a range of 25 dB and was limited by electronic components external to the fiber filter itself. Extension of the fabrication technique to include hundreds of taps at intervals as short as several picoseconds may be possible.

ISSN:0003-6951    

DOI:10.1063/1.94261

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

A simple method is described for the measurement of temporal characteristics of short picosecond‐nanosecond laser pulses in the visible and near IR. It relies on the photoacoustic detection of two‐photon absorption in thallous halides in an otherwise conventional correlation experiment.

ISSN:0003-6951    

DOI:10.1063/1.94262

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

We have shown for the first time that a detailed and systematic study of the threshold‐wavelength and the threshold‐temperature dependences at different lasing wavelengths of laser diodes with built‐in frequency selective feedback (FSF) mechanisms such as distributed feedback lasers, distributed Bragg reflector lasers, and lateral‐evanescent field distributed feedback lasers, can be conveniently performed by utilizing external cavity semiconductor lasers with frequency selective feedback. The results obtained show that the position of the FSF lasing mode within the spectral gain profile of the laser significantly affected the threshold current and threshold‐temperature dependence.

ISSN:0003-6951    

DOI:10.1063/1.94263

出版商:AIP    

年代:1983

数据来源: AIP