An optical fast frequency modulation code division multiple access communication system is proposed. In this system, an electrically controlled tunable optical filter (TOF) is used to encode the modulated broadband light source. The code depends on the function set to the controller. Two-dimensional code named functional code is also proposed based on a shifted sine function. The function defin...

A novel scheme for the optical generation and coherent detection of tunable narrow-band far-infrared radiation in free space is described. This technique involves the optical heterodyning of two linearly chirped broadband pulses to produce a quasi-sinusoidal intensity modulation at tunable terahertz frequencies. The frequency content of the narrow-band terahertz radiation produced by mixing chi...

In this paper, we propose a method that can be used for image texture recognition in the presence of concurrent rotation and scale changes with tunable directional bandpass Gabor filter banks. The method relies on the analysis of the frequency spectra of the image textures, and from which the rotation and scale changes are estimated using a new spectral shift measure. Tunable Gabor filter banks...

In this paper, frequency-tunable microstrip antennas, for cognitive radio applications, are proposed. The approach is based on electrically tuning the antenna’s operating frequency by integrating reconfigurable band pass filters into wideband antenna structures. The design of an open loop resonator (OLR)-based bandstop filter, and its transformation to a bandpass filter, are investigated first....

An optical dynamic frequency hopping code division multiple access communication system is proposed. In this system, an electrically controlled tunable optical filter (TOF) is used to encode the modulated broadband light source. The code depends on the function set to the controller. The function defines the dynamic hopping pattern of the central wavelength of the transmitted narrowband optical...

Optical traps or tweezers use the forces exerted by structured beams of light to confine and manipulate non-intrusively and non-destructively microscopic objects including living cells and bacteria, with high accuracy. This technique provides unique means to control the dynamics of small particles and played a revolutionary role in areas of the physical and biological sciences. This manuscript ...

We report a new kind of broadly tunable optical bandpass filters based on unusual properties of long-range surface plasmon polaritons. A 0.004 variation in the refractive index of the dielectric medium translates into 210 nm of bandpass tuning at telecom wavelengths. The tuning mechanism reported here may be used to create compact and widely tunable optical systems and other plasmonic component...

In this paper, an optical filter based on a two dimensional photonic crystalring resonator (PCRR) with triangular lattice is designed and presented. For thispurpose, the effects of positioning, arrangement and the number of the inner rods of thedual-curved PCRR on the performance characteristics of our optical filter such as thetransmission coefficient and the quality factor have been fully inv...