Study of a MOEMS XOR gate based on optical ring resonator

Based on ring resonator with Microelectromechanical systems, optical XOR logic gate is proposed in this paper to realize the optical logic gate application. The proposed gate is basically structured on an optical ring resonator with 7µm radius and resonance wavelength of 1.55µm which is placed on the edge of a thin SiC circular diaphragm. In order to apply input voltages to electrodes, two very thin circular gold layers with 50nm air gap spacing are deposited under the diaphragm. Input voltages are considered as logic inputs and resonance wavelength shift as logic output. When an input DC voltage is applied across the diaphragm, an attractive electrostatic force is created between two electrodes. As a result, the diaphragm is deformed and an internal stress is created. This in turn changes the resonator refractive index due to the photoelastic effect and thus shifts its resonance wavelength about 35nm. COMSOL Multiphysics and MATLAB are carried out to verify FEA and numerical analysis of the designed structure, respectively. A good agreement between the simulations and analytical results is obtained. Enhancement of the wavelength shift and FSR are resulted. The proposed structure is used as an optical XOR gate for the first time.

Effective Control of the Optical Bistability of a Three-Level Quantum Emitter near a Nanostructured Plasmonic Metasurface

We study, theoretically, the phenomena optical bistability and multistability of a hybrid quantum-plasmonic system immersed within an optical ring cavity. The hybrid quantum-plasmonic system consists of a three-level V-type quantum emitter and a two-dimensional plasmonic metasurface of gold nanoshells. The quantum emitter and the plasmonic metasurface are placed in close proximity to each other so that a strong quantum interference of spontaneous emission occurs, which enables the strong modification of optical-bistability/ multistability hysteresis curves. Along with this, the strong interaction between the emitter and the plasmonic metasurface allows for active control of the corresponding bistable threshold intensity. Furthermore, we show that by varying the metasurface-emitter separation, a transition from bistability to multistability of the hybrid system is observed. Lastly, by introducing an additional incoherent pumping in the system, we have the emergence of phenomena, such as probe absorption and gain, with or without population inversion. The results may find technological application in on-chip nanoscale photonic devices, optoelectronics and solid-state quantum information science.

Modelling of symmetrical quadrature optical ring resonator with four different topologies and performance analysis using machine learning approach

The communication network based on the optical system requires more precise and efficient devices and equipment. Optical ring resonator is a versatile device used as a filter, delay line, add/drop multiplexer, switch, sensor and analyzer etc. We modelled the new symmetrical quadrature optical ring resonator (SQORR) and proposed four different topologies architecture for the multiple optical ring resonator. The performance of the proposed symmetrical quadrature optical ring resonator is assessed using regression based machine learning (ML) approach utilizing an Artificial neural network (ANN) with various checks are done to validate the approximations like error histogram, time series response, error autocorrelation, input-error correlation and mean-square-error (MSE). The best validation performance is 8.8486e-9 stopped at 103 for rhombus topology, 8.347e-9 stopped at 242 epochs, 8.8486e-9 stopped at 311 epochs for horizontal topology and 5.8012e-09 stopped at 373 epochs for square topology. The significance of the work is to increase FSR (free spectral range) by adding rings and wide FSR achieved 299.79 THz (maximum) and throughput of 0.027 W/m for rhombus topology and other performance parameters of the optical ring resonator using symmetrical rings. Such structure is small in the size and easy to fabricate. Even by the same number of rings using different topologies structure, we can vary the performance parameters as per the different applications.

Instability Risk and Beam Profile Variation in Optical Ring Resonator due to Thin Gradient Index Lens

In this study, a simple ring resonator model in presence of thin gradient index (GRIN) lens is investigated to characterize the optical beam maginification quality beyond its traditional modalities. This model allow us to vary and control the limit of resonator stability more significantly.It consist of two folding arms and each arm can be realized by its cavity components. Insertation of thin GRIN lens ( thickness < 9.3mm) in ring resonator, mainly in between first folding range gives the magnified output beams and meets the beam expander feature for the laser. Variation of GRIN lens thickness (L) is an emphatic and influencing parameter than its refractive index (n) to disturb the resonator stability. Resonator stability in Tangential (T) plane is relatively more sensitive than sagittal (S) plane. Vigorous magnification in optical beam size at the end of output range in a cavity is the noticeable consequences because of GRIN lens.