Let T be a symmetric directed tree, i.e., a tree with each edge viewed as two opposite directed links. We consider the problem of routing arbitrary sets of connection requests in T. In all-optical communication tree networks with WDM (wavelength-division multiplexing) this is equivalent to color (assign wavelengths to) a given set of directed paths so that no two directed paths of the same colo...

A major obstacle in realizing fast packet switching in all-optical networks is the large tuning delays of tunable optical devices. This paper proposes a multiaccess scheme for all-optical local area networks which employs both wavelength and code concurrency. In this scheme, several users share a wavelength channel through code multiplexing. The delay performance of hybrid wavelength/code divis...

The sensitivities of two species of sunfish (Lepomis gibbosus and Lepomis cyanellus) to the electric field (E-vector) of polarized light were assessed by compound action potential recordings from the optic nerve of live fish. Under white light and long wavelength adapting backgrounds, two cone mechanisms were found with maximum sensitivities in the long wavelength (lambda max approximately 620 ...

There are several challenges in the development of semiconductor lasers for the near mid-infrared region of 2-3 μm. Approaches being developed to produce lasers in this range include extending the wavelength of inter-band diode lasers which perform relatively well below ~2.5 μm. Such lasers are, however, strongly affected by increased optical losses and non-radiative Auger recombination which d...

The stability of an infinitely long, inviscid but compressible liquid jet under sinusoidal disturbances of the surface, still assumed to be sharp, is considered. This extends Rayleigh's theory. We show that despite compressibility the unstable region is /.> kc = 2na (/. wavelength, a radius) as Rayleigh's criterion for incompressible liquids states. The character of the unstable long wavelength...

We present the design of a demultiplexer based on photonic crystals (PC). The control of the refractive index, periodicity, geometry and size of the structure, are very important to light propagation in PC. The demultiplexer is intended to separate pulse channels with 1.3 and 1.55 μm wavelength into wide pass band wavelength division multiplexing (WDM) optical telecommunications systems. The de...

We report the realization of electron intraband absorption based middle~;5.6 mm! and long~;10 mm! wavelength infrared ~IR! photoresponse for normally incident radiation on InGaAs-capped GaAs~001!/InAs quantum dots ~QDs! in a n – i(QD) – n structure. The relative photoresponse in this dual-wavelength structure is tunable up to two orders of magnitude with bias. The full width at half maximum of ...

An optical filter unit is demonstrated, which uses two successively arranged tunable thin-film optical band-pass filters and allows for simultaneous adjustment of the central wavelength in the spectral range 522-555 nm and of the spectral bandwidth in the range 3-16 nm with a wavelength switching time of 8 ms∕nm. Different spectral filter combinations can cover the complete visible spectral ran...

The wavelength tuning properties of a tunable external cavity laser based on multiplexed volume holographic gratings and a commercial micromirror device are reported. The 3x3x3 cm(3) laser exhibits single mode operation in single or multi colors between 776 nm and 783 nm with less than 7.5 MHz linewidth, 37 mW output power, 50 μs rise/fall time constant and a maximum switching rate of 0.66 KHz ...

today, use of nanotechnology for cancer therapy is an active field of research. early detection, accurate diagnosis, and individual treatment are the aims which cause nanotechnology as an attractive area for research. among metallic nanomaterials, gold nanostructures have unique properties which make them remarkable candidates for biomedical approaches. surface plasmonic resonance (spr) effect ...