The paper presents a current tunable multifunction filter using current conveyor. The proposed circuit can be realized as on chip tunable low pass, high pass, band pass and elliptical notch filter. The circuit employs two current conveyors, one OTA, four resistors and two grounded capacitors, ideal for integration. It has only one output terminal and the number of input terminals may be used. F...

Tunable light filters are critical components for many optical applications in which light in-coupling, out-coupling or rejection is crucial, such as lasing, sensing, photovoltaics and information and communication technology. For this purpose, Bragg mirrors (band-pass filters with high reflectivity) represent good candidates. However, their optical characteristics are determined during the fab...

This paper presents a tunable bandpass filter based on the varactor-loaded composite rightand left-handed transmission line (CRLH-TL). The proposed filter is composed of one CRLH-TL unit cell, which corresponds to the third-order bandpass filter. The tunable bandpass filter is designed using only lumped-elements. The use of lumped elements saves space and lowers the fabrication cost. The size o...

A wavelength-tunable single-frequency fiber laser based on the spectral narrowing effect in a nonlinear semiconductor optical amplifier (NL-SOA) is proposed and experimentally demonstrated. The single-frequency operation is achieved based on the spectral narrowing effect resulted from the inverse four-wave mixing in a NL-SOA. By incorporating the NL-SOA in the fiber laser cavity, single-frequen...

Utilizing the small bending radius of high index contrast optical waveguides, ultra-compact optical devices such as waveguide branch, Mach-Zehnder interferometer, arrayed waveguide grating filter, microring resonator filter, and so on can be realized. We have proposed and demonstrated a vertically coupled microring resonator as an Add/Drop filter, and recently realized a hitless wavelength chan...

An optoelectronic implementation of a spiking neuron model based on the FitzHugh-Nagumo equations is presented. A tunable semiconductor laser source and a spectral filter provide a nonlinear mapping from driver voltage to detected signal. Linear electronic feedback completes the implementation, which allows either electronic or optical input signals. Experimental results for a single system and...

We investigate in detail the origin of multiple resonance peaks experimentally observed in an all-fiber acousto-optic tunable filter built with a photonic crystal fiber having slightly deformed air-hole structure and non-circular outer cladding. A model for the acousto-optic mode coupling in the PCF is formulated taking into account both the acoustic and the optical birefringence. All experimen...

We describe a scheme in which a camera is turned into an efficient tunable frequency filter of a few-Hertz bandwidth in an off-axis, heterodyne optical mixing configuration, enabling one to perform parallel, high-resolution coherent spectral imaging. This approach is made possible through the combination of a spatial and temporal modulation of the signal to reject noise contributions. Experimen...