Channel Drop Filter Research Articles

High quality and sensitivity phononic crystal channel drop filter to detect ethyl lactate in mixtures of ethyl lactate and 2-butoxy ethanol

This paper introduces a new sensing approach utilizing a solid-solid phononic crystal (PnC) channel drop filter structure for the detection of varying molar fractions of Ethyl lactate within a mixture of Ethyl lactate and 2-butoxy ethanol. The sensor features a two-dimensional PnC constructed from poly methyl methacrylate as the background material, incorporating a regular arrangement of circular Tungsten columns. The design integrates a bus waveguide linked to two interconnected ring resonators, which are coupled to a drop waveguide. Each ring resonator is equipped with three strategically positioned pillars near the coupling region, allowing for the accommodation of varying concentrations of Ethyl lactate. The sensor’s performance is significantly influenced by the ring resonators and the integrated pillars. It identifies specific resonance frequencies that shift in response to changes in Ethyl lactate concentrations within the resonators. The transmission resonance frequency exhibits valuable sensitivity to these concentration variations, reflecting the unique sound velocities and mass densities associated with each level of Ethyl lactate. The effectiveness of the proposed sensor is validated through coupled mode theory, demonstrating a close match with the device’s observed behavior. The measured frequency range spans from 1.972 MHz to 1.979 MHz with a step size of 1 Hz. Notably, the sensor displays considerable characteristics, including an average quality factor of 90,613, an average sensitivity of 3816 Hz, an average figure of merit of 172, an average signal-to-noise ratio of 137, an average resolution of 22 Hz, an average damping ratio of 0.56 × 10− 5, and an average limit of detection of 34 × 10− 5. These results underscore the potential of the channel drop filter for the accurate detection of Ethyl lactate concentrations with high quality factor and sensitivity. The sensor can effectively identify variations in Ethyl lactate levels, which are prevalent in various applications, including pharmaceuticals and food additives.

Design of Channel Drop Filters Based on Photonic Crystal with a Dielectric Column with Large Radius inside Ring Resonator

Photonic crystal channel drop filters (CDFs) play a vital role in optical communication owing to their ability to drop the desired channel. However, it remains challenging to achieve high-efficiency CDFs. Here, we demonstrate a highly efficient three-channel CDF with both high transmission and high quality (Q) factor based on a novel ring resonator that is in the middle of two waveguides. A dielectric column with a large radius replaces the homogeneously distributed dielectric columns inside the ring cavity to modulate the coupling ratio with a straight waveguide, thereby enhancing the transmission and Q factor. The transmission and Q factor of the single-cavity filter are 99.7% and 12,798.4, respectively. The mean value of the three-channel filter based on the basic unit can reach up to 94.6% and 10,617, respectively, and a crosstalk between −30.16 and −50.61 dB is obtained. The proposed CDFs provide efficient filter capability, which reveals great potential in integrated optoelectronics and optical communication.

Exploring the performance of 2-D square lattice photonic crystal channel drop filters with varying horizontal cavity dimensions

Exploring the performance of 2-D square lattice photonic crystal channel drop filters with varying horizontal cavity dimensions

A novel 2D-PhC based ring resonator design with flexible structural defects for CWDM applications

In this article, a chain-shaped photonic crystal-based ring resonator (PhCRR), which can function as a channel drop filter (CDF), is designed using two-dimensional photonic crystals. Silicon rods with a refractive index of 3.44 are chosen, and they are perforated in the air with a refractive index of 1 for the PhCRR layout design. Silicon material is selected for realizing the PhCRR-based channel drop filter because it exhibits nearly zero absorption in the C-band (1530–1565 nm) spectral region. The PhCRR structure is established within two-dimensional hexagonal lattices. Transmission efficiency, quality factor, and sensitivity are critical parameters in the design of optical components. Our proposed ring resonator achieves a transmission efficiency of 99.7% with a quality factor of 4550 at a wavelength of 1551 nm. To analyze the drop filter’s functionality, we calculate the electric field distribution of two-dimensional photonic crystals at 1551 nm and 1553 nm. We employ the FDTD numerical analyser to extract simulation results, and the plane wave expansion solver method is used to estimate the photonic band gap of the designed resonator. The chain-shaped photonic crystal-based ring resonator is designed to operate in the third optical window wavelength, which offers very low loss (less than 0.2 dB). The proposed PhCRR is designed to operate within the conventional band range of 1530 to 1565 nm and can be used for various applications such as tunable add/drop multiplexing, optical filters, signal routing and switching in CWDM applications, free space communication systems, and photonic integrated circuits.

High coupling efficiency photonic crystal waveguide for compact channel drop filter design on silicon-on-insulator platform

High coupling efficiency photonic crystal waveguide for compact channel drop filter design on silicon-on-insulator platform

High performance of photonics crystals Demux with an integrated channel drop filter based on annular periodic ring cavity

Abstract In this work, we are interested in the design of a basic filter structure based on an annular ring cavity where we study its characteristics and its performance in terms of transmission and selectivity of the signal. The basic structure is a 2D photonic crystal (PC) with holes in the substrate which are more suitable for different PC manufacturing processes. Based on the optimization of the filter structure results, we created a high performance structure and improved a 4 channels demultiplexer (DEMUX) with an optical parameters which are the transmission efficiency, the quality factor and the crosstalk with average values of 97.25, 3171 and −26.58 dB, respectively, it had a significant role in optical communication networks. The compact size of the proposed DEMUX is 211.7 μm2 which is suitable for the integrated optics. To determine the photonic band gap (PBG) of our proposed structure, we used the plane wave expansion (PWE) method and the finite difference time domain (FDTD) method used to study normalized transmission.

A PhC-SOA based cancerous cell detection biosensor

In this paper, we present a novel method to design an ultra-small photonic integrated biosensor to detect cancerous cells. The proposed biosensor is based on the self-phase modulation in PhC-SOA, inducing a frequency shift on a pulse traveling through the device. The amount of the frequency chirp depends on the group velocity of the active medium waveguide being determined by the refractive index of the microfluidic infiltrating the holes around the waveguide. The refractive index of the microfluidic is also determined by the cell type that can be normal or cancerous. Since the refractive index of a cancerous cell is higher than that of a normal one, the group index of the waveguide and the output chirp will decrease. By measuring the amount of the output chirp, we can detect the cell type. The Simulation results showed that for a 0.02 change in the refractive index of the cell, a 3.71 nm central wavelength shift occurred for a 10-ps 7-mW gaussian pulse input with a central wavelength of 1533.53 nm. In terms of the wavelength shift, the sensitivity and figure of merit are 185.5 and 530, respectively. To detect the cell type, we integrated a PhC channel drop filter to drop the chirped signal due to the cancerous cell infiltration. Designing an appropriate PhC-CDF leads to achieving an ultra-small cancerous detection cell biosensor with more than 97% precision.

Design and analysis of a channel drop filter and demultiplexer based on a photonic crystal super ellipse-shaped ring resonator

In advanced optical communication systems, a photonic crystal (PC) based channel drop filter (CDF) and dense wavelength division multiplexer (DWDM) demultiplexer are essential components in the design of a complete DWDM system, which offers a high transmission data rate. In the present work, a novel PC, CDF filter and demultiplexer based on a ring resonator with a super ellipse shape is designed and analyzed. To design a high-performance device, the performance parameters of the proposed components, such as transmission efficiency, spectral line width, channel spacing, Q-factor and crosstalk, are investigated. The proposed CDF is designed to drop a resonant wavelength with a high quality factor of 3955, and the ring resonator design is extended to the demultiplexer. The demultiplexer is designed to drop the four resonant wavelengths of 1579.8 nm, 1582 nm, 1583.6 nm and 1574.9 nm, respectively. The observed high quality factor (3955), bandwidth (0.4 nm) and transmission efficiency (90%) of the proposed demultiplexer will support high-performance DWDM systems

Photonic crystal analysis for multiplexer and de-multiplexer applications

In our present work, we have made an investigation of several theoretical tools using the finite element method depending on the COMSOL MULTIPHYSICS program, for intuitive insight into the optical properties of the optical crystal. Analysis of the bandgap of a two-dimensional periodic photonic crystal with square lattice, evaluate the photonic band structure by the eigenfrequency of the unit cell of the first Brillouin zone. Moreover, creating defect mode inside the bandgap of photonic crystal, such as a resonant cavity, waveguide defect, narrowband filter, sharp drop filter, channel drop filter, waveguide bends, waveguide splitter promises us to a platform to design devices that includes a certain optical range of wavelengths. The transmission, as a result, the influence of the light localized in the defect area of the periodic structure of the photonic crystal. This study is important for producing photonic integrated circuits based on photonic crystals for future advanced optical communication.

Transmittance Prediction and Inverse Design of Microring Resonator Channel Dropping Filters With Deep Learning

We propose a method to use deep learning to achieve transmittance prediction and inverse design of microring resonator channel dropping filters. We transform the transmittance prediction and inverse design into model training problems, which learn and approximate the intrinsic interactions from the geometric parameter space to transmittance space and the transmittance space to geometric parameter space. The test loss and mean square error for the transmittance prediction case are 3.94888×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−2</sup> and 4.68901×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−3</sup> , respectively; the test loss and mean square error for the inverse design case are 7.27015×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−3</sup> and 4.0029×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−4</sup> , respectively. The numerical results suggest that the models developed by deep learning can make an efficient prediction of the transmittance and achieve excellent performance of the inverse design for microring resonator channel dropping filters, validating the effectiveness and feasibility of the approach we propose. With generalization ability within the given design space, the well-trained models can produce fast and accurate results without the need for time-consuming numerical calculations or case-by-case design.

Chalcogenide Photonic Crystal: Channel Drop Filter

In the present paper, we have studied a two-dimensional photonic crystal structure of square lattice as channel drop filter application. Photonic crystal structure of square lattice was constructed with circular rods are embedded in air medium. The channel drop filter was designed with a point defect cavity nearby a waveguide, which constructed by removing a single row of rods near cavity. The cavity was designed by removing a number of rods, which characterized with dimension of the cavity. The transmission spectra were analyzed for the channel drop filter with the dimension of the cavity.

Fully integrated 3-bit all-optical analog to digital converter based on photonic crystal semiconductor optical amplifier

Integrating a photonic crystal based semiconductor optical amplifier (PhC-SOA) composed of InP/InGaAsP/InP heterostructure with eight PhC based channel drop filters (CDFs) based on an InGaAsP platform, we have designed a fully integrated all-optical 3-bit analog to digital converter (AO-ADC). A probe signal after passing through a 9-µm long PhC-SOA in the presence of an amplitude-modulated Gaussian pulse of 1.422 ps width and maximum energy of 37.2 fJ exhibited a 4.8-nm wavelength shift. The eight appropriately designed PhC-CDFs have coded the chirped signal into eight quantization levels. The numerical results show that the proposed structure can convert analog photonic signals into 3-bit digital output with no missing code at 10Gs/s. The proposed AO-ADC structure with a small footprint of 455 μm2, along with its ultra-low power consumption, can pave the way for the further development of the next-generation integrated photonic chips.

DEMUX with low crosstalk and compact channel drop filter based on photonics crystals ring resonator with high quality factor

Abstract The optical components based on photonic crystal had a wide range of applications fields these last years. In this work, we propose a configuration of photonic crystal structure of Channel Drop Filter (CDF). The proposed filter study by finite difference numerical method in the time domain FDTD makes it possible to ensure an average detected modal transmission rate of 95.30%, an average quality factor of order 3149.12 and a compact size of 144.65 μm2 with high sensitivity to small variation of refractive index, period and radius of rods. Thus, we designed demultiplexer with four channels, which has a low average crosstalk of −30.73 dB. The transmission and the quality factor are 90.94% and 2221.13 respectively, with channel spacing 4.2 nm and a size of 405.6 μm2. These properties make our model of the proposed filter and demultiplexer well adapted for the realization of optical integrated circuit.

A Topological Photonic Ring-Resonator for On-Chip Channel Filters

A topologically protected ring-resonator formed in valley photonic crystals is proposed and fabricated on a silicon slab. The unidirectional transmission and robustness against structure defects of its resonant modes are illustrated. Coupled with topological waveguides, the topological ring is functioned as notch and channel-drop filters. The work opens up a new avenue for developing advanced chip-integrated photonic circuits with attributes of topological photonics.

An integrated 2-bit all optical analog to digital converter based on photonic crystal semiconductor optical amplifier

In this paper, by integrating InP/InGaAsP/InP Photonic crystal semiconductor optical amplifier (PhC-SOA) with photonic crystal channel drop filters (PhC-CDF), we present a novel fully integrated ultra-small low-power all-optical analog to digital converter (AO-ADC). The self-phase modulation in the PhC-SOA can shift the frequency of the Gaussian input pulse. The two output PhC-CDFs are designed in a way that appropriately codes the frequency-shifted pulse by the PhC-SOA, which consequently converts them to four desired digital output levels. The numerical results indicated that the center wavelength of an amplitude modulated Gaussian pulse with a center wavelength of 1551.228 nm, temporal pulse-width of 10.6 ps, and energy of 74.4 fJ can be shifted by 1.652 nm. This shift is accommodated by utilizing a PhC-SOA with a length of 9 µm and an injection current of 6.5 mA. The shifted pulse is then quantized and coded to the four digital levels of (00, 01, 10, 11) by two point-defect PhC-CDFs. The PhC-CDFs minimize the AO-ADC integral and differential nonlinearity (INL/DNL) errors by compensating for the effect of the nonlinear frequency shift induced by PhC-SOA. The proposed design offers a footprint of 142 µm2 AO-ADC working at 10 Gs/s.

Optical Channel Drop Filter Design Based on PCRR and Micro Cavity Resonator

Optical channel drop filter (OCDF) plays a key role in optical communication networks for filtering the individual wavelength among the group of channels in wavelength division multiplexing systems. There are several channel drop filters with different design mechanisms available in the literature, but those structure dimensions are not compact enough for the photonic integrated applications. Hence, in this paper, a compact and efficient OCDF is developed in the triangular lattice PC structure based on diamond-shaped photonic crystal ring resonator (PCRR) mechanism combined with micro cavity resonator (MCR). The developed OCDF is analysed for different operating wavelengths by considering the different positions of MCR around the main PCRR. Based upon the position of the MCR around PCRR, the three dropping wavelengths such as 1540 nm, 1550 nm, and 1570 nm are observed at the output waveguides with 100% dropping efficiency. Then the structural and performance parameter comparison is done between the proposed and existing structures in terms of device dimension, dropping efficiency, and quality factor. It is depicted through the results that the quality factor and the device dimension are better than that of the existing structures for 1550-nm wavelength.

Design and analysis of tunable acoustic channel drop filter based on fluid–fluid phononic crystal ring resonators

We propose a novel approach to design a tunable acoustic channel drop filter based on a fluid–fluid phononic crystal (PnC), using two ring resonators. A square lattice of infinitely long cylindrical water inclusions is embedded in the mercury matrix to characterize the PnC structure. We show that the output resonant frequency can be ultra-tuned by changing the location of each ring, and the quality factor can be enhanced. This property is also used to select the output port, either selecting a forward or backward dropping port. Numerical results show that the quality factor (Q) of the structure is Q=2000 in which its center frequency is 69.990KHz. Moreover, the effect of different temperatures (10°Cto 40°C) and pressures (0.1MPa to 5MPa) on the performance of the channel drop filter is explored. The observations of this work can be useful for the design of an acoustic temperature/pressure sensor. Furthermore, we investigate the effect of aqueous binary mixtures of Na3PO4 in water, and show that our proposed structure is useful for determining the compositions of liquid mixtures by changing the effective path length of the acoustic wave.

Reverse design of microring resonator channel dropping filters

We present a reverse solving design approach to achieve accurate control over the response shapes and resonant peak positions of channel dropping filters implemented by coupled microring resonators. From performance to geometry, we obtain the geometric parameters based on the layout connecting multiple cells consisting of two straight waveguides and one microring in series to achieve the desired filter performance. We discuss the theoretical limit that the filters can reach and how to obtain the geometric parameters corresponding to the desired response reversely. Finally, the numerical simulations are carried out, and the results agree well with theoretical analysis, verifying the efficacy of our approach.

Low Dimensional Channel Drop Filter for CWDM Optical Communication Networks

This work presents salient features of an optical wavelength channel drop filter based on two-dimensional photonic crystal technology. The photonic band gap of two-dimensional Photonic Crystal (2-DPC) channel drop filter has been obtained by using plane wave expansion (PWE) method. The parameters of the channel drop filter have been optimized for telecommunication wavelengths 1611 nm and 1631 nm with a refractive index contrast of 3.79 and 3.96 using Gallium Antimonide (GaSb) dielectric material. The number of dielectric rods in X and Z directions were taken as 21, and 20, respectively with a spacing of 540 nm of having elliptical rod radius 0.15µm & 0.1 µm. The proposed design gives around 98% dropping efficiency with a good quality factor about 352. This ultra-compact structure is proposed which can be used for Coarse Wavelength Division Multiplexing (CWDM) applications and photonic integrated circuits.

Photonic crystal ring resonator based optical MUX/DEMUX design structures: a survey and comparison study

For the past few decades, the design of photonic crystal (PC)-based optical devices and components are mainly focused by several researchers as miniaturisation becomes a crucial need in many integrated applications. In optical communication system, the PC-based wavelength division multiplexer and demultiplexer is considered as one of the most essential component as it offers high transmission rate in single optical fibre by performing multiplexing operation. Due to its major role, numerous optical MUX/DEMUX structures based on different design mechanisms like resonant cavity, super prism effect, cascading multiple channel drop filters, coupling and cascading the PC waveguide, defect waveguides and photonic crystal ring resonator (PCRR), etc., have been reported and analysed so far. However, despite the various mechanisms, the design structure based on PCRR mechanism has attracted the attention of many researchers in recent years due to its design flexibility, high quality factor and low loss which satisfies the requirements of major applications. Hence, the main aim of this paper is to discuss about the various existing design structures of optical MUX/DEMUX based on PCRR mechanism along with its respective pros and cons. Further, the comparison of their corresponding structural and performance parameters is also tabulated in detail. From the literature review and comparison study, the future design considerations are suggested for the researchers which would be helpful for them in designing better structure with improved performance.