All-optical thermo-plasmonic device

We demonstrate an all-optical thermo-plasmonic effect to switch/modulate the surface plasmon resonance signal intensity excited at the metal-air interface. This optically addressed thermo-plasmonic measurement scheme is suitable to amplify very small changes in the complex dielectric constant (ε(m)(T)) of thin gold (Au) film, induced by the Ar(+) laser. The predominant contributions due to small but highly repeatable transient photo-thermal effects in the complex metal dielectric constant is confirmed to be the reason behind the highly reproducible all-optical thermo-plasmonic device performance presented here.     

All-optical Integrated Nonlinear Devices

Abstract

The field of third-order nonlinear integrated optics is reviewed, with emphasis on intensity-dependent phenomena for all-optical device applications. The most relevant material issues are briefly summarized.     

All-optical quaternary logic gates

Conventional binary logic based operations restrict the speed of operations as well as information handling capacity. A way to overcome these limitations is the implementation of multivalued logic operations in the optical domain. Multivalued logic operations not only enhance the data handling capacities but also increase the speed of processing. integrating enormous potential bandwidth of optical fiber as information carrying medium and faster optoelectronic/optical switches with no hardware complexity. A new method is proposed for the implementation of all-optical quaternary inversion, MAX, MIN, and equality operations using frequency-encoded data. Cross phase modulation-based frequency conversion, polarization switch (PSW) characteristics of a semiconductor optical amplifier (SOA), frequency routing by a wave division multiplexer (MUX), and a demultiplexer (DMUX) have been exploited to implement the desired quaternary logic operations. Simulation results support the feasibility of the proposed scheme.     

Concatenated All-optical Loop Mirror Switches

Abstract

Synthesis of a sharp switching characteristic is experimentally demonstrated by concatenation of nonlinear optical loop mirrors. A novel configuration has been used which results in three terminal operation of the device. This device can be used as a logic gate and for pulse shaping to produce square pulses.     

Inlaying nanoscale surface recess patterns with nanoscale objects

A simple and versatile approach to constructing patterns on a solid surface using nanoscale objects is demonstrated. The approach is essentially an inlaying process, in which recess patterns fabricated on a surface are selectively filled with nanoscale objects. The objects are anchored firmly on the surface due to the spatial confinement provided by the recess structures. Protein molecules and inorganic nanoparticles are used in this demonstration. Cyclic voltammetry is used to detect electron transfer signals from patterns of protein molecules. The approach suggests a potentially fast, high-throughput and versatile technique for constructing architectural structures on a solid surface using nanoscale objects.     

All-optical nonlinear joint Fourier transform correlator

We present the first all-optical nonlinear joint transform correlator based on a square-law receiver in the Fourier plane. Our device uses a photorefractive limiting quadratic processor. The compressional nonlinearity associated with the transfer function of the limiting quadratic processor enables the correlator to detect signals embedded in Gaussian and non-Gaussian noise. In the limiting region this device correlates the phase-only information of the input. This is the first time to our knowledge that photorefractives or real-time holography has been used in the correlation of the phase-only information. We demonstrate the operation of this device experimentally, and we evaluate its performance throughcomputer simulation for various forms of noise.     

Nonlinear Interference Devices for All-optical Self-routeing

Abstract

Conceptual devices for all-optical self-routeing are discussed, based on particular interference phenomena associated with modified, nonlinear Fabry-Perot cavities. The transmitted amplitude and phase are calculated for cavities composed of III-V semiconductor materials. Within the physical optics approximation the transmission of Gaussian beam profiles and their associated diffraction patterns are obtained. By engineering an asymmetry in the transmitted phase which depends upon the input intensity, an angular deflection of the beam profile can be produced under optical control. The simplest examples indicate that deflections of a beam through several degrees are theoretically feasible. Practical implementations of this effect are discussed.     

All-optical stage of an omega network

All-optical multistage interconnection networks are desirable for overcoming the limitations of optical signal regeneration in switching systems. We present a new implementation of the perfect-shuffle interconnection pattern that is coupled with an all-optical switching element, forming a complete stage of a multistage network. Switching is performed with birefringent calcite crystals and a ferroelectric liquid-crystal device, while interconnection is achieved with a space-semivariant imaging configuration. Cascading the layout allows this system to be used to construct an all-optical multistage interconnection network. An experimental demonstration of the stage is presented.     

All-optical time-division demultiplexer using semiconductor switching

An all-optical time-division demultiplexer system is proposed that employs semiconductor switching. The technique can be applied through the use of input infrared signals of wavelengths ≥1 μm. The device is simple to construct and has a potential capacity of 1 Tbit/s, with cross talk between channels of only approximately -13 to -17 dB at operating wavelengths between 1 and 15 μm, respectively. The optimum characteristics and the operational parameters are also presented.     

All-optical poling of a chalcohalogenide glass

Second harmonic generation has been achieved in a GeGaS chalcohalogenide glass (ChHg) after all-optical poling of the sample by coherent superposition of the fundamental and the second harmonic pulses of a Q-switched and mode-locked Nd:YAG laser. The set of parameters which optimize the effective quadratic non-linear coefficient has been identified.     

All-optical bistability in doped-polymer film waveguides

All-optical bistability was observed in thin-film waveguides made with acceptor-donor substituted azobenzene-doped poly(methyl methacrylate) polymer. Input-output curves with hysteresis characteristics were measured. The origin of the bistability was attributed to nonlinear coupling between a prism and a doped-polymer waveguide. An approximately theoretical analysis was introduced. Theoretical predictions were qualitatively consistent with experimental results.     

Self-assembled nanoscale ferroelectrics

Multifunctional ferroelectric materials offer a wide range of useful properties, from switchable polarization that can be applied in memory devices to piezoelectric and pyroelectric properties used in actuators, transducers and thermal sensors. At the nanometer scale, however, material properties are expected to be different from those in bulk. Fundamental problems such as the super-paraelectric limit, the influence of the free surface, and of interfacial and bulk defects on ferroelectric switching, etc., arise when scaling down ferroelectrics to nanometer sizes. In order to study these size effects, fabrication methods of high quality nanoscale ferroelectric crystals have to be developed. The present paper briefly reviews self-patterning and self-assembly fabrication methods, including chemical routes, morphological instability of ultrathin films, microemulsion, and self-assembly lift-off, employed up to the date to fabricate ferroelectric structures with lateral sizes in the range of few tens of nanometers.