摘要:

The performance of a logic inverter based on injection locking in laser diodes is presented. The fast commutation rise and fall times (5 and 2 ns, respectively) allow a 150 MHz repetition rate. Due to the gain existing in laser diodes, low optical switching energies (50 fJ) and large fan‐out rates (30) are also obtained, making such an inverter attractive for the purpose of parallel optical computing, particularly if semiconductor laser arrays are used in place of single laser diodes.

ISSN:0003-6951    

DOI:10.1063/1.102650

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

A miniature external cavity has been fabricated from a single 4.5 mm substrate for coherent beam addition of a linear AlGaAs laser array. Binary‐optics elements are fabricated on the front surface for laser beam collimation and onto the back surface for lateral mode selection. Near‐diffraction‐limited performance has been observed with up to 80% of the far‐field power contained in the central lobe.

ISSN:0003-6951    

DOI:10.1063/1.102644

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

A new mode‐locking technique, self‐mode‐locking, is described which uses the detected optical pulses from the mode‐locked laser as the active driving source. This technique forms narrow‐width mode‐locked optical pulses at low repetition rates without the use of a microwave synthesizer.

ISSN:0003-6951    

DOI:10.1063/1.102658

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

InGaAs/AlGaAs laser diode arrays fabricated with differing amounts of In in the quantum well active layer are characterized by threshold currents of 115 A/cm2, transparency currents of 50 A/cm2, optical losses of 3 cm−1, and wavelengths to 960 nm for In compositions of 20%. Gain coefficient measurements indicate an increase from 0.0535 to 0.0691 cm &mgr;m/A for quantum well lasers with 0% InAs and 10–20% InAs, respectively. The maximum output power achieved for a device with a 100 &mgr;m aperture is 3 W cw.

ISSN:0003-6951    

DOI:10.1063/1.102647

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

We report the fabrication of single‐mode channel waveguides in spun films of polydiacetylenes using an inverted rib design. These robust guides consist of a planar layer of the polydiacetylene spun on a glass substrate in which high‐index channels have been defined by ion exchange. Models of such guides show that most of the optical field of the guided wave is confined to the polymer layer, with the high‐index glass channels providing lateral confinement. End‐fire coupling of 1.06, 1.15, 1.32, and 1.55 &mgr;m light into the composite guides resulted in single‐mode guiding with the light confined to the polymer layer. This approach to waveguide formation should be applicable to a wide range of polymeric materials.

ISSN:0003-6951    

DOI:10.1063/1.102648

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

This letter reports the demonstration of grating‐surface‐emitting (GSE) lasers with threshold current densities as low as 440 A/cm2. When the distributed‐Bragg‐reflector sections were cleaved from these lasers, the resulting edge‐emitting lasers had threshold current densities that were essentially unchanged from that of the GSE laser. However, the operating wavelength of the Fabry–Perot laser was typically 70 A˚ shorter than that of the surface emitter.

ISSN:0003-6951    

DOI:10.1063/1.102649

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Novel structure TE/TM mode selective optical channel waveguides are proposed and fabricated in GaAs/AlAs superlattices (SLs) using impurity‐free disordering induced by SiO2cap annealing. The disordered SL regions are found to be useful as low‐loss waveguides even at a wavelength close to the absorption edge of the as‐grown SL. By observing the near‐field patterns, it is confirmed that these channel waveguides could selectively confine TE or TM polarized light.

ISSN:0003-6951    

DOI:10.1063/1.103274

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

We report the results of an experimental investigation of plasma‐assisted oxidation of SO2to SO3. A coaxial dielectric‐barrier discharge is used to generate atomic oxygen to carry out the reaction. The dielectric‐barrier discharge, which is an interrupted discharge, is very efficient in producing atomic oxygen and requires a simple form of excitation. We have observed a significant reduction (up to 90%) in the SO2concentration using this technique. The results of varying the gas composition, the gas pressure, and the gas flow are also reported.

ISSN:0003-6951    

DOI:10.1063/1.102651

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Ion beam induced epitaxy of amorphous Si layers onto ⟨100⟩ substrates has been investigated by varying the As concentration. At As concentrations below 4×1018/cm3no rate effect is observed. In the intermediate regime, between 4×1018/cm3and 2×1021/cm3, the growth rate increases linearly with the logarithm of As concentration and reaches a value about a factor of 2 higher than that of intrinsic Si. At concentrations above 2×1021/cm3, the epitaxy experiences a sudden, severe retardation. Finally, at a concentration of ∼6×1021/cm3, twins are observed to form.

ISSN:0003-6951    

DOI:10.1063/1.102635

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

High quality GaAs films with dislocation densities of less than 1×106cm−2on (100) Si substrates have been obtained by selective area growth using the metalorganic chemical vapor deposition method. Remarkable reduction of residual stress and dislocation density in the GaAs layers due to selective area growth have been analyzed using a simple model, in which the assumptions are that the generation of dislocations is caused by thermal stress in the films and dislocation density reduction in GaAs films on Si due to selective growth is caused by stress relief.

ISSN:0003-6951    

DOI:10.1063/1.102636

出版商:AIP    

年代:1990

数据来源: AIP