摘要:

We describe a new method of operation of symmetric self‐electro‐optic effect devices (S‐SEEDs) using excitation pulses shorter than the diode sweep out times. We shall call this dynamic SEED switching. Previous SEEDs are optically bistable logic devices which use the unique properties of multiple quantum well structures placed in the intrinsiciregions of twop‐i‐ndiodes reverse biased in series. Conventional operation of S‐SEEDs is at the exciton wavelength where absorption decreases with increasing electric field. Utilizing the dynamic properties of the S‐SEED we demonstrate that switching is possible at any wavelength where there is a nonlinear response showing a threshold. The major advantages of dynamic over conventional operation, is that it can be faster while requiring less optical energy, is automatically reset each cycle, and is less susceptible to saturation.

ISSN:0003-6951    

DOI:10.1063/1.105920

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

Strained InGaAs/AlGaAs quantum well diode lasers have been fabricated on Si substrates for the first time. A GaAs buffer layer was grown on each Si wafer by temperature‐cycled organometallic vapor phase epitaxy (OMVPE). The wafer was then transferred to a second reactor for OMVPE growth of a graded‐index separate‐confinement heterostructure single‐quantum well laser structure. For lasers with a cavity length of 1000 &mgr;m, room‐temperature pulsed threshold current densities as low as 174 and 195 A/cm2have been obtained for active layer compositions of In0.02Ga0.98As and In0.05Ga0.95As, respectively. One laser with an In0.05Ga0.95As active layer operated cw for 56.5 h, a record lifetime for GaAs‐based diode lasers on Si.

ISSN:0003-6951    

DOI:10.1063/1.105921

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

We analyze the possibility of creating population inversion and optical gain in a specially designed resonant tunneling superstructure when the energy between active quantum levels is greater than the optical phonon energy. Each of twenty periods of the structure represents a complete resonant tunneling, double quantum well diode designed to provide escape time from the lower level of the active well much shorter than the electron‐optical phonon relaxation time. Three heterostructure materials are considered: InAs/AlSb, InGaAs/AlAs, and GaAs/AlAs. In all three cases optical gains of 50–90 cm−1were calculated to be present for the photon energy of ≊0.1 eV.

ISSN:0003-6951    

DOI:10.1063/1.105922

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

Coherent infrared (IR) image bundle was developed for the delivery of the IR thermal image. The fiber employed was the As2S3glass core of 65 &mgr;m diam and Teflon (perfluoronated ethylene propylene) cladding of 75 &mgr;m diam, which has the transmission range in the wavelength region between 1 and 7 &mgr;m. Two kinds of bundles of 100 cm long were prepared, which consisted of 1550 fibers (NPB75‐1550) and of 8400 fibers (NPB75‐8400). The IR imaging system was constructed by coupling the bundle to an IR television camera. The performance of the system was investigated by detecting the thermal image of an operating LSI package.

ISSN:0003-6951    

DOI:10.1063/1.105923

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

The high‐power integrity of strained single quantum well InGaAs/AlGaAs lasers grown by molecular beam epitaxy is investigated. In the high‐power regime, the lifetime of theLz=7 nm strained quantum well laser emitting at &bartil; 980 nm is found to be limited by the air‐cleaved facets. However, a comparison with lattice‐matched 7 nm quantum well GaAs/AlGaAs lasers, which otherwise have an almost identical vertical structure shows a substantial lifetime improvement. This indicates that lattice hardening due to the indium in the quantum well is effective in the facet region. The investigations demonstrate the feasibility of 150 mW single mode operation with sufficient lifetime for practical applications in the wavelength range of &bartil;1 &mgr;m.

ISSN:0003-6951    

DOI:10.1063/1.105924

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

Efficient all‐optical modulation of mid‐infrared radiations based on photoinduced intersubband absorption of a GaAs/AlGaAs multiquantum well structure is demonstrated at room temperature. The sample designed for mid‐infrared waveguiding was grown by molecular beam epitaxy. A double‐resonance spectroscopy of both interband and intersubband transitions of the quantum wells is presented. The intersubband resonance is found at 9.56 &mgr;m. An AlGaAs laser diode is used to optically pump the quantum wells. On/off modulation ratios as high as 150:1 are obtained with only 45 mW pump power and for mid‐infrared input powers up to 0.5 W. The frequency bandwidth of the device is presently comparable to that of acousto‐optic modulators available at mid‐infrared wavelengths.

ISSN:0003-6951    

DOI:10.1063/1.105925

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

The first experimental demonstration of a surface‐normal bistable optical switching device based on the monolithic integration of a vertical‐cavity surface‐emitting laser and apnpnphotothyristor is reported. By the use of ion implantation, it is shown that the positive feedback in the photothyristor can be controlled, thus enabling the integration of both bistable and latching optical switches on the same epitaxial structure. High contrast (30 dB) and an optical gain of 8 are demonstrated.

ISSN:0003-6951    

DOI:10.1063/1.105926

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

We investigate the ultrafast electro‐optic response and sensitivity of a poled side chain polymer film via the electro‐optic sampling technique. A 760 fs rise‐time electrical transient is observed corresponding to a bandwidth of 460 GHz. We believe this to be device limited and not due to limitations in the speed of response of the polymer.

ISSN:0003-6951    

DOI:10.1063/1.105927

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

We measure the room‐temperature polarization‐dependent nonlinear absorption and refractive‐index spectra of a (Al0.5Ga0.5As)1/2(GaAs)1/2fractional‐layer superlattice (FLS) structure grown by metalorganic chemical vapor deposition. The anisotropic nonlinear effects between the directions parallel and perpendicular to the superlattice give rise to a nonlinear optical birefringence in the plane of the growth surface. From our measurements using a femtosecond optical pulse, we derive the magnitude and spectral shape of the nonlinear optical birefringence. We describe the basis of an all‐optical polarization rotation switch using the FLS structure.

ISSN:0003-6951    

DOI:10.1063/1.105928

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

Quasi‐phase‐matched room‐temperature frequency doubling to generate blue, green, and red light was demonstrated using periodically poled LiNbO3crystals. A 1.24‐mm‐long sample in an external resonant cavity generated 1.7 W of green power from an input of 4.2 W at the 1.064 &mgr;m Nd:YAG laser line when heated to 140 °C to compensate for a slight error in periodicity.  

ISSN:0003-6951    

DOI:10.1063/1.105929

出版商:AIP    

年代:1991

数据来源: AIP