摘要:

The fabrication and performance characteristics of frequency tunable two‐section distributed feedback lasers are reported. The lasers are of the double channel planar buried heterostructure type and utilize a second order grating for frequency selective feedback. The laser emits in a single frequency with a cw linewidth of ∼50 MHz. The single frequency output can be tuned by ∼2 A˚ by varying the current through one of the two sections. Electronically tunable sources of this type are potentially useful for coherent fiber transmission systems.

ISSN:0003-6951    

DOI:10.1063/1.96900

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Below‐threshold studies of an injection‐locked gain‐guided diode laser array show a far‐field emission pattern with several lobes whose angular widths decrease with increasing frequency of the injected radiation. The concurrent increase in the far‐field emission angle with the frequency of the injected radiation provides strong evidence that the interelement coupling in a gain‐guided diode laser array depends upon the tilt of the wave front in the array cavity. These results provide insight into the coupling mechanism that dominates gain‐guided array behavior and strongly suggest that these devices should be viewed as perturbed broad‐area devices in which plane waves are undergoing multiple reflections between facets. This contrasts sharply with the coupled‐mode picture, which is more appropriate for index‐guided arrays.

ISSN:0003-6951    

DOI:10.1063/1.96901

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

We demonstrate for the first time low‐loss optical guiding in In‐doped GaAs. Ridge waveguides are made with single In0.012Ga0.988As ternary layers and In0.2Ga0.8As‐GaAs superlattices. Attenuation constants of ∼1.3 dB/cm are measured and the principal loss mechanism is identified to be scattering at the ridge walls. It is expected that improved fabrication techniques will lead to guides with attenuation ≤0.5 dB/cm.

ISSN:0003-6951    

DOI:10.1063/1.96902

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

A high contrast (5:1), 1.3 &mgr;m wavelength opticalandgate is demonstrated using a bistable Fabry–Perot InGaAsP/InP laser amplifier with large gain. Using simple arguments, it is shown that, subject to realistic constraints, the maximum attainable contrast ratio in a bistable Fabry–Perot logic gate is about 10. Unlike bistable amplifiers, there is a significant trade‐off between contrast and gain in passive devices.

ISSN:0003-6951    

DOI:10.1063/1.96903

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

A Monte Carlo simulation of a magnetized cathode‐glow region for a carbon dioxide laser discharge has been undertaken. The computational findings appear to confirm recent observations that the magnetic stabilization effect is due primarily to a Lorentz driven mixing motion of charge carriers at or near the cathode electrode surface.

ISSN:0003-6951    

DOI:10.1063/1.96852

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Epitaxial growth of (100) GaAs on (100) silicon was achieved by excimer laser annealing of amorphous GaAs layers at 248 nm. An AlAs encapsulation layer was found to be necessary to prevent the loss of arsenic during laser annealing. An energy density of 105 mJ/cm2was the critical energy density for recrystallization. Field‐effect transistors were fabricated on the regrown (100) GaAs and resulted in a transconductance of 70–80 ms/mm.

ISSN:0003-6951    

DOI:10.1063/1.96853

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

The influence of dose rate, i.e., ion flux, on ion beam mixing in Nb‐Si bilayer samples was measured at room temperature and 325 °C. At the higher temperature, an increase in dose rate of a factor of 20 caused a decrease in the thickness of the mixed layer by a factor of 1.6 for equal total doses. At room temperature, the same change in flux had no effect on mixing. These results are consistent with radiation‐enhanced diffusion theory in the recombination‐limited regime.

ISSN:0003-6951    

DOI:10.1063/1.96854

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

The radial variation in electrical and optical characteristics of Si‐implanted InP:Fe wafer activated by rapid thermal annealing has been studied. The sheet carrier concentration (Ns) followed similar radial variation as etch pit density (EPD) whereas the photoluminescence (PL) intensity of C‐Zn acceptor peak varied inversely with EPD. A maximum electron mobility of 2500 cm2/V s and electrical activation of 35% have been obtained for 3×1012cm−2, 200 keV Si+implants annealed for 15 s in the range 700–850 °C. A high intensity peak centered at 1.350 eV was also observed in the PL spectra of the samples and tentatively assigned to a Si‐defect complex.

ISSN:0003-6951    

DOI:10.1063/1.96855

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Capacitance‐voltage measurements have been simulated to find the conduction‐band discontinuity in ann‐type GaAs‐Al0.3Ga0.7As heterojunction. In the calculations the partial ionization of the donor level in the (Al,Ga)As is taken into account. It is found that exact knowledge of the donor depth is a prerequisite in order to infer the conduction‐band discontinuity from capacitance‐voltage measurements. For a dopant concentration of 3×1016cm−3on either side of the heterojunction the same apparent carrier profile is obtained with a conduction‐band discontinuity equaling 65% of the total band‐gap difference and zero donor depth as with 75% discontinuity and 100 meV donor depth. It is also shown that compensation influences the apparent carrier profile. Taking literature values for the donor depth in Al0.3Ga0.7As the discontinuity of the conduction band is estimated to be 70% of the total band‐gap difference.

ISSN:0003-6951    

DOI:10.1063/1.96856

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Fluorine bubbles were observed in 5×1015/cm2BF+2‐implanted (001) and (111) Si annealed at 1000–1100 °C. Bubbles were found to form in samples annealed at 1100 °C for a time as short as 10 s. The bubbles were distributed mostly near the original amorphous/crystalline interface and silicon surface. The growth of bubbles was seen to be intimately related to the presence of residual defects. Possible ramifications of bubble formation in device applications are discussed.

ISSN:0003-6951    

DOI:10.1063/1.96857

出版商:AIP    

年代:1986

数据来源: AIP