摘要:

A new GaAs photodetector of low capacitance and with high sensitivity in the whole 0.8–1.4‐&mgr;m wavelength range has been fabricated from GaAs doping superlattices grown by molecular beam epitaxy. The highly doped yet semi‐insulating superlattice allows application of high reverse bias via selectiven+andp+electrodes also at room temperature. The excellent photoresponse of the totally depleted device at energies far below the GaAs energy gap arises from the existence of pronounced tail states in the forbidden gap region of the superlattice. Under operating conditions the capacitance of the detector depends only on the electrode geometry and can thus be kept extremely low. This implies high‐speed response of the device.

ISSN:0003-6951    

DOI:10.1063/1.95460

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

The variation in the intensity of the excitonlike luminescence lying 5–10 meV below the free‐exciton energy value specific to molecular beam epitaxially grown GaAs was studied under various growth conditions. The intensity of the luminescence increases with increasing CO in the background and/or decreasing As4/Ga flux ratio. Fourier transform infrared spectra indicated the existence of polynuclear carbonyls in the GaAs. The excitonlike luminescence may be caused by radiative recombination of excitons bound to CO incorporated from the ambient on an As site.

ISSN:0003-6951    

DOI:10.1063/1.95461

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Infrared optical fibers composed of Ge‐Se based chalcogenide glass have been fabricated by using a specially designed drawing apparatus. Transmission loss of less than 1 dB/m was observed in the IR region of 2–10 &mgr;m except at 4.5 &mgr;m. The minimum loss is 0.2 dB/m at 5.5‐&mgr;m wavelength.

ISSN:0003-6951    

DOI:10.1063/1.95462

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

A planar GaAs/GaAlAs double heterostructure stripe geometry laser with laterally effective step change of the refraction index is described. The planar structure is achieved by regrowing an embedded stripe selectively on a Be‐implanted stripe, using metalorganic chemical vapor deposition. The near‐field and the far‐field patterns confirm the index guiding mechanism of the light. The threshold current is comparable to those of similar lasers grown by uninterrupted growth process either by liquid phase epitaxy or by metalorganic chemical vapor deposition.

ISSN:0003-6951    

DOI:10.1063/1.95463

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Picosecond pulses have been generated over a broad spectral range with passive mode locking of dye lasers pumped by a long‐pulse XeCl laser. The rapid reduction of pulse duration to less than 10 ps was confirmed to occur within a few tens of round trips. The characteristics of mode locking were intensively investigated at the multiple wavelengths of rare‐gas halide lasers such as KrF, ArF, and XeCl lasers, resulting in pulse durations of 5.5 ps at 497 nm and 7 ps at 580 nm, respectively.

ISSN:0003-6951    

DOI:10.1063/1.95464

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

For an optically bistable system with induced absorption the transport equations for the light intensity and the excitation density are solved. Under pulse operation a kink in the excitation density is found, which moves discontinuously in the beam direction and causes a sawtooth variation in the transmitted intensity.

ISSN:0003-6951    

DOI:10.1063/1.95465

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

A new class of instabilities is reported in a semiconductor laser which is coupled to an external optical cavity with an intracavity Fabry–Perot etalon. Power spectra of the laser suggest periodic oscillation and its subharmonic modulations. The calculated results, using the van der Pol equation which includes a carrier density‐dependent refractive index, are outlined to explain the observed subharmonic modulation phenomena.

ISSN:0003-6951    

DOI:10.1063/1.95447

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Enhanced frequency modulation in cleaved‐coupled‐cavity lasers is analyzed and results for frequency deviation per unit modulator current and lasing spectra are presented. Strong sensitivity to gap spacing and bias point are reported and nonlinearities are shown to limit distortionless analog frequency modulation. In a typical case, a 40‐&mgr;A peak modulation current produces a 200‐MHz maximum frequency deviation with 2% distortion.

ISSN:0003-6951    

DOI:10.1063/1.95448

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

An alternative approach which makes use of a laser to reduce a polymer/complexed metal ion matrix to generate small reflective surfaces is described. The thermal energy provided by the laser promotes an electron transfer from the polymer to the metal ion to form metal. Since the reduction occurs within the thermal profile of the focused laser beam, the reflective area has a diameter close to that of the beam waist. We have formed ∼l‐&mgr;m‐diam reflective areas using a pulsed diode laser. Application of this method to optical disk recording is discussed.

ISSN:0003-6951    

DOI:10.1063/1.95449

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

We have fabricated InGaAsP gain‐guided laser arrays emitting at 1.3 &mgr;m. These devices have threshold currents in the range 300–400 mA at 30 °C and have been operated to pulsed output powers as high as 400 mW. More than 100 mW of output power has been obtained up to an ambient temperature of 60 °C. The lasers emit in multilongitudinal modes with a far‐field divergence of 20°×35°. A gain‐guided InGaAsP laser array of the type described here can be used in some applications requiring high‐power lasers emitting at 1.3 &mgr;m.

ISSN:0003-6951    

DOI:10.1063/1.95450

出版商:AIP    

年代:1984

数据来源: AIP