摘要:

We present theoretical and experimental results describing the intensity noise in the ultrahigh efficiency tandem‐contact single quantum well laser. We find that the substantial increase in the modulation efficiency of these lasers is accompanied by only a marginal increase in the intensity noise.

ISSN:0003-6951    

DOI:10.1063/1.104032

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

A Ga0.8In0.2As/GaAs thermally actuated optical switch has been demonstrated for unpolarized 1.08 &mgr;m light. Its measuredon:offcontrast ratio of 4.7 was produced electrically by changing the applied voltage from 0 to 3.2 V on a device with a 2.25‐&mgr;m‐thick Ga0.8In0.2As active layer. The ‘‘on’’ insertion loss was 3.8 dB. Theon:offchange in Ga0.8In0.2As absorption coefficient was 6660 cm−1. The switching current density was 9.7 A/cm2. The thermal switching energy can be supplied optically for an all‐optical switch.

ISSN:0003-6951    

DOI:10.1063/1.104033

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

We report significant improvement in the optical switching times of symmetric self‐electro‐optic effect devices due to enhanced tunneling by using a 35 A˚ barrier versus the previous 60 A˚ barrier thick multiple quantum well GaAs/AlxGa(1−x)As devices. Also, the voltage required for bistability was reduced from 10 V in the thick barrier devices to 3 V in the thin barrier devices with no apparent degradation in the contrast ratio.

ISSN:0003-6951    

DOI:10.1063/1.104034

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

A time‐resolved pump‐probe configuration employing 10 ps laser pulses has been used to investigate the all‐optical switching characteristics of zero‐gap directional couplers containing a single quantum well. All‐optical switching of the weak probe pulses from one port into the adjacent one was obtained at pump input pulse energies of 150 pJ. The switching takes place within the duration of the laser pump pulses. The recovery time of the device was found to be ∼1.5 ns which indicates that carrier diffusion plays a major role in the device switching speed.

ISSN:0003-6951    

DOI:10.1063/1.104035

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Monolithic bistable e´talons with a GaAs/Al0.3Ga0.7As multiple quantum well active layer and AlAs/Al0.1Ga0.9As Bragg reflectors have been fabricated by metalorganic vapor phase epitaxy. They exhibit a very good memory effect. Experiments with an additional external beam at the same and at a different wavelength have been performed. They demonstrated thresholding, pulse shaping, amplification, and wavelength conversion. Moreover, the use of a diode laser external beam showed the possibility of controlling an intense beam with a weaker beam. We describe an experimental configuration in the reflection mode and at normal incidence, which allows mixing the two input beams and extracting the output beam with an ideal 100% efficiency.

ISSN:0003-6951    

DOI:10.1063/1.104036

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

We demonstrate control of the optical coupling between a pair of planar waveguides by application of voltage to surface‐stabilized ferroelectric liquid‐crystal films between them. A prototype switch exhibited a response time of 200 &mgr;s and a 40:1 switching ratio.

ISSN:0003-6951    

DOI:10.1063/1.104037

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

We have devised a novel vertical‐cavity top surface‐emitting GaAs quantum well laser structure which operates at 0.84 &mgr;m. The laser combines peripheral current injection with efficient heat removal and uses only the epitaxially grown semiconductor layers for the output mirrors. The structure is obtained by a patterned deep H+implantation and anneal cycle which maintains surface conductivity while burying a high resistance layer. Peripheral injection of current occurs from the metallized contact area into the nonimplanted nonmetallized emission window. For 10‐&mgr;m‐diam emitting windows, ∼4 mA thresholds with continuous‐wave (cw) room‐temperature output powers ≳1.5 mW are obtained. Larger diameter emitting windows have maximum cw output powers greater than 3 mW. These are the highest cw powers achieved to date in current injected vertical‐cavity surface‐emitting lasers.

ISSN:0003-6951    

DOI:10.1063/1.104038

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Data are presented demonstrating a strong influence of a closely spaced AlAs/GaAs distributed Bragg reflector on the spontaneous emission characteristics of an InGaAs‐GaAs quantum well. The mirror to quantum well spacings on different crystal samples correspond to optical path lengths of either 1/4, 1/2, or 3/4 of the emission wavelength. The samples are characterized using photoluminescence, electroluminescence, and reflectivity measurements. Spontaneous emission is found to be greatly enhanced for a 1/2 wavelength spacing, while 1/4 and 3/4 spacings suppress the spontaneous emission by a factor of ≳1000.

ISSN:0003-6951    

DOI:10.1063/1.104120

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

GaAs/GaAlAs laser diodes with reactive ion etched facets have been demonstrated for the first time with high output powers (5 W from 100‐&mgr;m‐wide apertures), high output power density (15 MW/cm2), and high slope efficiencies (66%) in junction‐up configuration under quasi‐cw operation. Mirror etching was performed in a pure SiCl4gas environment by maintaining a low background pressure and gas pressure. High quality etched facets have been achieved with almost no scattering loss.

ISSN:0003-6951    

DOI:10.1063/1.104039

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

We describe, for the first time, the preparation of InGaAs/InP homojunction confined buried‐heterostructure lasers by high vacuum processing techniques. Lithography and waveguide mesa etching were carried out using ultrathin native oxide masking, focused Ga ion beam writing, and free Cl2etching. Base laser structures and overgrowth were carried out by atmospheric pressure metalorganic vapor phase epitaxy. The resulting lasers have low‐threshold currents of ∼62 mA.

ISSN:0003-6951    

DOI:10.1063/1.104042

出版商:AIP    

年代:1990

数据来源: AIP