摘要:

We study periodic structures constructed by low resistivity Si wafers which allow only the transmission of electromagnetic waves incident at a certain angle. We call those materials angular filters. The angular width of the transmission peak can be controlled by changing the thickness of the structure and/or by changing the resistivity of Si wafers. The basic idea behind the unusual properties of those materials lies on the Borrman effect or anomalous transmission of x rays through the crystals. Measured responses are in good agreement with theoretical simulations. Although the present structure was designed and built to work at around 100 GHz, similar structures can be designed for any other frequency region. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116518

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

A scheme to generate an optical matrix from a mode‐locked Nd:YAG laser has been theoretically explored and experimentally demonstrated. The matrix consists of highly synchronized and sequentially delayed optical pulses suitable for use with two‐dimensional array optoelectronic devices and clock distribution system. The output pulses have the same state of polarization and no timing jitter is produced among the elements. Encoded outputs have been generated from the matrix using a set of photomasks. This technique can be applied to high‐speed optical parallel processing. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116519

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

The reproducible micromachining of hollow metal tips on Si cantilevers and their applicability to scanning probe microscopy techniques are described. Provided with apertures below 130 nm and hollow pyramidal tips proved to be highly suited probes for scanning near‐field optical microscopy (SNOM). First results of combined SFM/SNOM measurements together with scanning electron microscopy (SEM) photographs of the new sensors are presented. The SNOM images show a resolution of about 100 nm demonstrating the usefulness of these probes. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116520

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

We examine the behavior of self‐pulsating laser diodes when injected with periodic optical signals. We experimentally and theoretically investigate the phase difference between the injected optical signal and the synchronized self‐pulsating laser diode emission. We explore the phase difference dependence on detuning between the laser free‐running self‐pulsation frequency and the applied signal frequency, and on the injected signal power. The determined sensitive dependence of the phase difference on these factors has important consequences when self‐pulsating lasers are used as optical signal processing elements in all‐optical communication networks, where such sensitivity may lead to timing problems. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116521

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

A four channel polarization and wavelength separation element using substrate‐mode stacked holograms is proposed based on the diffraction efficiency characteristics for polarization and the wavelength selectivity of a transmission‐type phase volume grating. We fabricated a sample device and measured its polarization selectivity, output spectrum, and insertion loss of each channel to demonstrate its performance. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116522

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Pulse compression by sum frequency generation is demonstrated in femtosecond time domain with a type II phase matching BBO crystal. By frequency mixing in BBO crystal infrared signal and idler pulses of 160 fs duration generated by an optical parametric amplifier, sum frequency pulses as short as 34 fs were obtained. Experiments and computer simulations demonstrate the potential of this technique to produce ultrashort pulses with high conversion efficiency. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116523

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Self‐sustained pulsating 650‐nm‐band AlGaInP visible lasers were fabricated by adopting a new structure, which has a highly doped saturable absorbing (HDSA) layer. Since the doping level and the thickness of the HDSA layer could be controlled accurately by using metalorganic vapor phase epitaxy growth technique, a stable operation of self‐sustained pulsation up to 60 °C was obtained. The lasers operated over 1350 h under the average output power of 5 mW at 60 °C. The relative intensity noise values were below −136 dB/Hz in the temperature ranging from 20–60 °C and remained unchanged after life test. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116524

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

We report the demonstration of a magneto‐optic sampling technique that allows for the detection of picosecond electrical pulses propagating down a microstrip transmission line. A unique feature of the method is that it directly measures thecurrentin ultrashort electrical pulses. The technique is based on time‐resolved detection of the magneto‐optic Faraday effect in a Bi‐substituted yttrium‐iron‐garnet (Bi‐YIG) film. The detailed magnetic response is found to be in excellent agreement with the Bloch‐Bloembergen equations. The bandwidth of the sampling system has been demonstrated to scale with the ferromagnetic resonance frequency up to 82.3 GHz, with a potential for increase towards 1 THz. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116632

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Two‐photon pumped frequency upconversion cavity lasing at ∼610 nm is accomplished in a dye‐doped polymer fiber system, pumped with ∼12 ns and 1.06 &mgr;m IR laser pulses. The dopant is a novel dye, trans‐4‐[p‐(N‐hydroxyethyl‐N‐methylamino)styryl]‐N‐methylpyridinium iodide, abbreviated as ASPI, which possesses a greater two‐photon absorption cross section and stronger upconversion fluorescence emission compared to common commercial dyes (such as rhodamine 6G). Using aQ‐switched Nd:YAG pulse laser as the pump source, cavity lasing could be achieved in a 3‐cm‐long ASPI‐doped poly(2‐hydroxyethyl methacrylate) solid fiber of 100 &mgr;m diameter. The experimental results of spectral, temporal, spatial, and input–output characteristics of the cavity lasing are presented. The slope efficiency of upconversion lasing was 0.9%. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116633

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Second order nonlinearity via corona poling at room temperature in a Corning 7059 glass film on a Pyrex glass substrate was studied. It was clearly pointed out that the origin of the induced nonlinearity in this waveguide was located at the interface region between a top layer glass film and a glass substrate. This region is formed to be a depletion layer in the consequence of a drift of positive ions towards a negative electrode during corona poling. X‐ray photoelectron spectroscopy measurement on the corona‐poled Pyrex glass substrate gave the evidence that the main mobile ions were sodium ions. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116634

出版商:AIP    

年代:1996

数据来源: AIP