Characteristics of Add Drop Filter using single and dual PCRR in square lattice

A Photonic Crystal Ring Resonator (PCRR) based Add Drop Filter is designed using two dimensional (2D) square lattice PC silicon rods in air host. The normalized transmission spectra for a single-ring and dual-ring configurations have been investigated using 2D Finite Difference Time Domain (FDTD). The filter characteristics such as coupling efficiency, dropping efficiency, resonant wavelength and Q factor are numerically analyzed for single ring and dual ring PCRR. It is noted that the coupling efficiency, dropping efficiency and Q factor of single ring circular PCRR with scatterer rod are 100%, 100% and 186.75, respectively. The backward dropping is observed in single ring PCRR whereas forward dropping are noticed in dual ring PCRR based ADF. The Photonic Band Gap (PBG) with respect to structural parameters such as the radius of the rod, lattice constant and refractive index difference, and propagation modes in periodic and nonperiodic structure are calculated by Plane Wave Expansion (PWE) method.     

Investigation on parameters affecting the performance of two dimensional photonic crystal based bandpass filter

A two dimensional Photonic Crystal based Bandpass Filter is designed by exploiting coupling between the quasi waveguides and the circular Photonic Crystal Ring Resonator (PCRR). The output efficiency, resonant wavelength and bandwidth of PCBPF are investigated by varying the dielectric constant of the structure. The normalized transmission spectra of circular PCRR are taken using 2D Finite Difference Time Domain method. The Photonic Band Gap is calculated by Plane Wave Expansion method. Close to 100% (Band II) output efficiency is observed over the wavelength range from 1,504 to 1,521?nm and 85% (Band I) is obtained at 1,420?nm through simulation. The full width half maximum bandwidth of these bands is 35 and 20?nm, respectively. Further, the parameters that affect the resonant wavelength, output efficiency and bandwidth of the filter such as size of the reflector, radius of the coupling rods, lattice constant, rod radius and number of rods in the structure are analyzed. The overall size of the proposed filter is 11.4?μm ×?10.2?μm, which is smaller than the filters already reported in the literature and highly desirable for Photonic Integrated Circuits.     

Design and optimization of photonic crystal based eight channel dense wavelength division multiplexing demultiplexer using conjugate radiant neural network

In this paper, two dimensional photonic crystal, based eight-channel demultiplexer is proposed and designed for DWDM applications. The performance parameters of the demultiplexer such as transmission efficiency, channel spacing, spectral line width, Q factor, and crosstalk have been evaluated. The proposed demultiplexer comprises of bus waveguide, drop waveguide and parellogram resonant cavity (PRC). The bus waveguide transmits light to the PRC and exits through respective drop waveguide. The PRC consists of a parellogram resonator with a nano ring cavity that is used for dropping eight specific wavelength for ITU-T G 694.1 standard with 50 GHz channel spacing. The circular ring resonator is placed above the PRC wherein a resonant air hole (Cr) is positioned for desired channel selection. The channel selection is done by altering the radius of the air hole. In addition, a conjugate radiant neural network is implemented for optimizing the radii of resonant air holes to select the required channel wavelength. The proposed device is very compact and it could be considered for implementing the photonic integrated circuits.     

Suppression of soliton self-frequency shift by upshifted filtering

We consider the effects of stimulated Raman scattering on ultrashort light pulses propagating in long-haul fiber transmission lines. We propose an efficient method for suppressing the soliton self-frequency shift by use of upshifted filters without any compromise in signal-to-noise ratio and with the pulse stability preserved.     

Suppression of sideband frequency shifts in the modulational instability spectra of wave propagation in optical fiber systems

In standard optical fibers with constant chromatic dispersion, modulational instability (MI) sidebands execute undesirable frequency shifts due to fiber losses. By means of a technique based on average-dispersion-decreasing dispersion-managed fibers, we achieve both complete suppression of the sideband frequency shifts and fine control of the MI frequencies, without any compromise in the MI power gain.     

Investigation on two dimensional photonic crystal resonant cavity based bandpass filter

In this paper, different cavities, namely quasi square, tri-quarter square, square, hexagonal, circular, elliptical, diamond and annular ring based photonic crystal bandpass filters (PCBPFs) are proposed and investigated by exploiting coupling between two in-line quasi waveguides and a resonant cavity. The resonant wavelength, output efficiency and bandwidth of designed PCBPFs are studied by varying the size of the cavity. The normalized transmission spectra of PCBPF are observed using 2D finite difference time domain (FDTD) method. The photonic band gap (PBG) is calculated by plane wave expansion (PWE) method. The circular cavity based PCBPF gives better performance than others because of its circular resonating modes. The number of passbands is increased linearly while increasing the size of the cavity. The overall size of the PCBPF chip is about 11.4 μm × 11.4 μm, which is more suitable for photonic integrated circuits (PIC), wavelength division multiplexing (WDM) systems and sensing applications.     

Distributed queue optical burst switched ring—A MAC protocol with zero blocking for OBS ring networks

Optical burst switching is a switching technology that is able to provide viable switching for optical internet with the present day technology. This paper presents a new medium access protocol for wavelength division multiplexing based optical burst switched metro ring network namely distributed queue optical burst switched ring (DQOBSR). It is a slotted, distributed queue access protocol with fixed bus structure and simple wavelength assignment. The topology consists of two unidirectional, counter rotating rings and the medium access protocol is based on distributed queuing. The protocol provides zero blocking with acceptable access delays. A mathematical model is also presented to determine the mean access delay which is the important performance parameter for the protocol. The simulation and model based results are compared and found to be in good agreement.