摘要:

We have measured the third harmonic generation spectra of epitaxial chloro‐indium phthalocyanine (ClInPc) thin films. The &khgr;(3)spectrum in the wavelength range of 970–1650 nm reveals resonance features of ClInPc. Theoretical analysis of the third‐order nonlinear optical channels in phthalocyanine allows the assignment of the observed resonances to three‐ and two‐photon resonances of &khgr;(3). ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114730

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

The appearance of broad photoluminescence (PL) bands in the energy range 0.70–0.96 eV in SiGe/Si heterostructures is shown to be related to the ion bombardment during the molecular beam epitaxy. From the optically detected cyclotron resonance, polarization, and postgrowth treatments, the PL is shown to be composed of at least two components. No evidence of lattice distortion is found for the main PL band, while the low energy tail is believed to arise from lattice distorted regions. Both PL centers are demonstrated to originate from the SiGe quantum wells by PL excitation measurements. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115042

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

A method for modulation of semiconductor lasers based on the modulation of the optical confinement factor is demonstrated. Using this method, an enhanced −3 dB bandwidth is observed in agreement with the small signal rate equation analysis. A modulation response that drops at high frequencies slower than the conventional direct current modulation response is achieved. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115043

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

We analyze the degradation process of proton‐implanted, top‐emitting vertical cavity surface emitting lasers using cross‐sectional cathodoluminescence. The spatially resolved luminescence characteristics of the active regions, andp‐ andn‐distributed Bragg reflector (DBR) mirrors before and after degradation of the devices are presented. Degradation has been observed not only in the active regions, but also remarkably in thep‐DBR mirror stacks. We show that a significant minority carrier population is present in thepmirror under normal operating conditions to drive the degradation observed in thepmirror. ©1995 American Institute of Physics. 

ISSN:0003-6951    

DOI:10.1063/1.115044

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Optical couplers are key components for signal distribution in optoelectronic transmitter/receiver modules. A new low‐loss large‐angleY‐junction hybrid polymer optical coupler incorporating an integrated microprism has been fabricated and demonstrated experimentally for use in a mixed‐signal module environment. The results show that the radiation loss is small with relatively wide branching angle as compared to a conventionalY‐junction coupler.

ISSN:0003-6951    

DOI:10.1063/1.115045

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Neutral‐donor‐bound exciton recombination (I2) dynamics have been studied by photoluminescence in an unintentionally dopedn‐type GaN epitaxial layer grown by metalorganic chemical vapor deposition. The luminescence emission line shape, peak position, and intensity as functions of temperature have been measured. In particular, time‐resolved emission spectroscopy has been employed to study the dynamic processes of the bound exciton recombination, from which the temperature and the emission energy dependencies of the recombination lifetime of this transition have been obtained. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115046

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Antennas based on commercially available GaAs as a photoconductor with a subnanosecond photocarrier lifetime have been used to detect subpicosecond free‐space electromagnetic radiation (THz pulses). At low optical gating intensities (≤1 mW/100 &mgr;m2), GaAs based antennas exhibit a higher responsivity and signal‐to‐noise ratio than typical antennas based on radiation‐damaged silicon‐on‐sapphire. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115047

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

We observed a dramatic improvement in the performance of polymer light‐emitting diodes (LEDs) upon light doping of the organic layer. The LEDs betrayed symmetrical electrical and light‐emission characteristics. Their turn‐on voltage is lower and their external quantum and power conversion efficiencies are higher by nearly an order of magnitude when compared with devices that utilized a nominally undoped organic layer. We attributed these results to the modification of the tunneling barrier in metal–polymer–metal junctions due to the presence of an induced polarization electric field associated with the ionized dopant counterions and charged polymer chains. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115048

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

We show that the high contrast property of vertical cavity asymmetric Fabry–Perot modulators can also be obtained in a waveguide geometry. Increasing the absorption in one arm of a waveguide directional coupler causes the transmission through the other arm to decrease, go to zero, and then increase again. Thus, by adjusting the coupling length and the absorption, an infinite contrast ratio can theoretically be obtained with a low insertion loss. The waveguide geometry is not only more convenient than normal incidence for fiber‐based devices, but also provides a larger optical bandwidth. We present the design equations and provide a first order model of device operation. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115049

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

We present a formula which can be used to analyze the anisotropic and apparent Faraday effect occurring in a material having an optically anisotropic property. By using the formula the real Faraday parameter can be obtained. For example, we have used the formula to study the anisotropic Faraday effect of a single‐crystal Cd0.55Mn0.45Te measured with the spectroscopic ellipsometer and rotating‐analyzer‐type Kerr apparatus. The calculated data were in good agreement with the experimental results. ©1995 American Institute of Physics.   

ISSN:0003-6951    

DOI:10.1063/1.115050

出版商:AIP    

年代:1995

数据来源: AIP