摘要:

We show that the supermodes of two coupled waveguides may exhibit a giant tunable group‐velocity dispersion, which allows for dispersion compensation in long‐haul fiber transmission lines, pulse compression, as well as bright soliton propagation in materials with large normal dispersion. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114736

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Efficient nonlinear or power‐dependent polarization switching in a semiconductor quantum‐well amplifier is reported. In the experiment, an amplifier with an InGaAs/GaAs single quantum well structure which lases at 974 nm is used. Efficient self‐switching is observed at 940 nm with signals 3 psec wide when gain and absorption saturation occur in the TM and TE polarization modes, respectively. The switching peak intensity is estimated to be lower than 13.2 MW/cm2. A theoretical model is adopted to show the consistent trends of switching behaviors with the experimental data. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114737

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Planar metal–diamond–metal photoconductive devices have been fabricated from free standing large grain (20–30 &mgr;m) polycrystalline thin film diamond. An interdigitated electrode design with spacings of 20 &mgr;m was used to produce effective UV photodetecting devices at bias values in the range 0.1–10 V. A methane‐air treatment has been used to modify the structures such that unprecedented performance characteristics have been recorded (106higher response to 200 nm than visible wavelengths, <0.1 nA dark currents); spectral features similar to those observed in natural diamond crystals have been observed indicating that the treatment used led to near ideal electronic characteristics from polycrystalline material. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114738

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Utilizing a type II interaction for second‐harmonic generation in a crystal of potassium titanyl phosphate, we experimentally demonstrate the all‐optical action of a light modulator with both signal and output at the same optical wavelength. This modulator is controlled by the intensity of the injected signal, a characteristic that makes it a suitable candidate for all‐optical transistor action and ultrafast analog processing in transparent networks for telecommunications. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114739

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

The inverse Faraday effect (IFE) in terbium gallium garnet (TGG) is observed at room temperature. A circularly polarized 532 nm optical pulse from a frequency doubled Nd:YAG laser traverses a TGG crystal, resulting in an induced voltage in a surrounding detection coil. Variation of laser intensity and polarization direction leads to changes in the induced voltage in accordance with Faraday’s law of induction. The IFE is attributed to the optical Stark effect. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114740

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

We report a quasi‐phase‐matched optical parametric oscillator (OPO) pumped by the second harmonic of a single frequencyQ‐switched Nd:YAG laser. Both the frequency doubling to 532 nm and the parametric oscillation are performed in periodically poled lithium niobate crystals with a nonlinearity of ∼15 pm/V. The OPO has been operated in ‘‘singly resonant’’ and ‘‘doubly resonant’’ configurations. The threshold in the singly resonant case was ∼0.14 J/cm2, more than one order of magnitude below the damage limit. OPO tuning from 945 to 1225 nm was achieved by changing both the period of domain reversal (from 6.8 to 6.85 &mgr;m) and the temperature of the crystal. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114741

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Near‐field scanning optical microscopy (NSOM) has been utilized to study the behavior of liquid crystals at room temperature. The material, 4′‐octyl‐4‐biphenylcarbonitrile (8cb) was studied at the air–liquid interface. The NSOM probe is shown to take an active role in modifying, and subsequently reading, the liquid crystal with about 65 nm resolution. The optical modification is proven to be independent of topographic modification. Results indicate potential technological uses in data storage and displays. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114742

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

This letter demonstrates that ion channeling patterns, produced by the passage of 3 MeV protons through a 0.5 &mgr;m thick [001] silicon crystal, can be transported and manipulated to produce enlarged or reduced area patterns using magnetic quadrupole lenses. The different effects on the ion channeling patterns obtained by using single quadrupole lenses and quadrupole multiplets are shown. The maximum attainable magnification under present conditions is investigated and a fundamental limitation to this process is identified as being the energy spread gained by the proton beam as it passes through the crystal. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114743

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Free‐space micro‐optical systems on a chip containing three‐dimensional microgratings have been demonstrated using surface‐micromachining technique. The micrograting is integrated with a rotary stage, a collimating micro‐Fresnel lens, and an edge‐emitting laser held by three‐dimensional alignment structures on a single Si substrate. Diffraction patterns for various grating rotation angles are observed. Another optical interconnect module consisting of three cascaded microgratings is also demonstrated. The micrograting is a basic building block for many micro‐optical systems and is very attractive for applications in microspectrometers, free‐space optical interconnect, optoelectronic packaging, and wavelength‐division multiplexed integrated micro‐optical systems. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114744

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

An electromagnetic stop band spanning about one octave is observed in a periodic structure consisting of a face‐centered‐cubic Bravais lattice of metal spheres supported by a low‐loss dielectric. The low‐frequency edge of the stop band is consistent with the Mie condition for the metallic spheres, and the center frequency of the stop band is a function of the lattice constant and the support dielectric material. For example, a sample having a cubic lattice constant of 1.65 cm, 3/8 in. diam chrome spheres at each atomic core, and Teflon support dielectric displayed a lower band edge of approximately 5.2 GHz, an upper band edge of about 12.8 GHz, and a maximum rejection at the center of the band of roughly 20 dB. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114745

出版商:AIP    

年代:1995

数据来源: AIP