摘要:

A hollow‐bore ridge waveguide technique for phase locking arrays of coupled CO2rf excited waveguide lasers was demonstrated. Stable phase‐locked operation of two‐ and three‐channel arrays has been demonstrated at the 50 W output level. Preliminary experiments with a five‐element array generated an output power of 95 W but phase‐locked operation was not conclusively demonstrated.

ISSN:0003-6951    

DOI:10.1063/1.96808

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Three‐dimensional features have been milled into optical materials by scanning a submicron focused gallium ion beam. Different shapes are obtained using computer controlled beam placement and dwell time during sputtering. We have used this technique to create micron‐sized facets and reflectors in the active areas of semiconductor lasers. Light output and quantum efficiency measurements indicate that these features are of sufficient quality to fabricate monolithic integrated optical devices. Some of the applications currently being investigated are laser‐detector pairs, coupled cavity lasers, lasers with integral lenses, distributed feedback lasers, confocal cavities, and laser cavity length tuning.

ISSN:0003-6951    

DOI:10.1063/1.96809

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

An experimental and theoretical study of large‐signal switching transients in directly modulated semiconductor lasers shows that the main parameters affecting high‐speed switching are the small‐signal relaxation oscillation frequency and the optical on/off ratio of the pulses. Simple expressions agree well with measured data and can be used to obtain an estimate of the maximum achievable modulation bit rate.

ISSN:0003-6951    

DOI:10.1063/1.96810

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

The lateral profile of the injection current along the active layer in multiple stripe laser diodes is analyzed for the practical case of homogeneous current density within each individual stripe contact. By means of conformal mapping an exact analytical solution is found for arbitrary contact configurations (number, width, and location) driven with different currents. The simple form of the solution eases the analysis of modal gain and supermode discrimination in gain‐guided and index‐guided arrays of stripe‐geometry laser diodes.

ISSN:0003-6951    

DOI:10.1063/1.96811

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Low threshold, optically pumped laser oscillation has been obtained using AlGaAs/GaAs double heterostructures grown on Ge‐coated Si substrates. The optical pump power for threshold is comparable to similar heterostructures grown on GaAs substrates. Between 20 and 85 °C the threshold temperature dependence is exponential withT0=160 °C. The laser wavelength and the peak of the spontaneous emission of lasers grown on Si substrates are shifted to longer wavelengths relative to bulk GaAs. This results largely from the strain in the plane of the epilayer produced by the difference in the thermal contraction of the layers and the Si substrate on cooling from the growth temperature.

ISSN:0003-6951    

DOI:10.1063/1.96812

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

High quality buried heterostructure (BH) lasers were grown by a two‐step metalorganic chemical vapor deposition. Single stripe BH lasers exhibited thresholds of 20 mA for a 1.2‐&mgr;m stripe. The spectral output emits in a single transverse and longitudinal mode up to 15 mW, with a side lobe suppression greater than 23 dB at 5 mW output. BH laser arrays were fabricated with threshold currents of 130 mA and differential efficiencies of 70% for a 10‐stripe array.

ISSN:0003-6951    

DOI:10.1063/1.97024

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

We present a linear theory to explain the experimentally observed emission angle scanning of an injection‐locked diode laser array when the frequency of the injected light is changed. This theory is based on eigenmode analysis of the coupled waveguides and on the use of the antenna array theory for the far‐field pattern. The experimental results are explained in terms of the resonant excitation of eigenmodes, which selects the far‐field pattern associated with the resonant mode. The agreement with published results is good.

ISSN:0003-6951    

DOI:10.1063/1.96813

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

We present results of pump‐probe experiments on GaAlAs laser diodes indicating a 0.9‐ps relaxation time associated with the device transmission. Subpicosecond, tunable near infrared pulses obtained by fiber compression were used to carry out the experiments. The data strongly support a model in which a nonequilibrium carrier temperature in the active layer is responsible for the observed signal.

ISSN:0003-6951    

DOI:10.1063/1.96814

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

The fabrication and performance characteristics of an independently controllable closely spaced dual wavelength laser structure are described. The laser structure utilizes semi‐insulating (Fe‐doped InP) layers both for confinement of the current to the active regions and for separation of the active regions of the two lasers. Both lasers emit in single frequencies near 1.55 &mgr;m by virtue of frequency selective feedback provided by a second order grating. The light coupled into a single mode fiber from both lasers is about 5 dB smaller than that for optimum coupling arrangement of each laser. Dual wavelength laser structures of this type are useful for wavelength multiplexed optical transmission systems.

ISSN:0003-6951    

DOI:10.1063/1.96815

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

This work presents a simple method for calculating the conductivity, electron temperature, and electric field in a high‐current hydrogen thyratron positive column as functions of the current density and electron density. The method is based on an analysis that takes into account the partially ionized nature of the plasma, and includes the effects of electron‐electron and electron‐ion collisions. Data are presented for a typical thyratron discharge (hydrogen pressure 0.4 Torr, current density 50–250 A/cm2, electron density 2–8×1014cm−3). The electron temperature is found to be close to 1 eV, while the electric field ranges between 5 and 15 V/cm.

ISSN:0003-6951    

DOI:10.1063/1.96816

出版商:AIP    

年代:1986

数据来源: AIP