The term photonic crystals appears because of the analogy between electron waves in crystals and the light waves in artificial periodic dielectric structures. During the recent years the investigation of one-, two-and three-dimensional periodic structures has attracted a widespread attention of the world optics community because of great potentiality of such structures in advanced applied optical fields. The interest in periodic structures has been stimulated by the fast development of semiconductor technology that now allows the fabrication of artificial structures, whose period is comparable with the wavelength of light in the visible and infrared ranges.

http://ieeexplore.ieee.org/iel5/6354/16969/00781867.pdf

Photonic crystals

SIMULATED ANNEALING AND BOLTZMANN MACHINES A Stochastic Approach to Combinatorial Optimization and Neural Computing

Based on photonic crystal ring resonators and nonlinear Kerr effect in this paper, we proposed a 2*4 all optical decoder switch. Our proposed structure has two logic input ports and one bias input port. This decoder switch has four output ports. Via these two logic input ports, we control the bias signal to transfer toward which output port. We employed numerical methods such as plane wave expansion and finite difference time domain methods for analyzing the proposed structure.

A 2*4 all optical decoder switch based on photonic crystal ring resonators

Optical sensors are widely used for refractive index measurement in biomedical, chemical, and food processing industries and offer high sensitivity to ambient refractive index variations due to the specific field distribution of the resonances. The sensor's sensitivity is greatly dependent on its material and structure. In this review, we focused on plasmonic refractive index sensors with no fluorescent labelling required. The latest developments on special types of plasmonic structures such as metal-insulator-metal waveguides and their application in refractive index sensors are presented. Moreover, numerous types of plasmonic waveguides, geometries, materials, fabrication processes, and losses related to plasmonic waveguides are explained to provide a better understanding of this topic. The highlight of this review is to discuss the spectral performance of recently reported refractive index sensors by emphasising their sensitivity and figure of merits.

Plasmonic sensors based on Metal-insulator-metal waveguides for refractive index sensing applications: A brief review

The paper proposes an ultra-narrow band graphene refractive index sensor, consisting of a patterned graphene layer on the top, a dielectric layer of SiO2 in the middle, and a bottom Au layer. The absorption sensor achieves the absorption efficiency of 99.41% and 99.22% at 5.664 THz and 8.062 THz, with the absorption bandwidths 0.0171 THz and 0.0152 THz, respectively. Compared with noble metal absorbers, our graphene absorber can achieve tunability by adjusting the Fermi level and relaxation time of the graphene layer with the geometry of the absorber unchanged, which greatly saves the manufacturing cost. The results show that the sensor has the properties of polarization-independence and large-angle insensitivity due to the symmetric structure. In addition, the practical application of testing the content of hemoglobin biomolecules was conducted, the frequency of first resonance mode shows a shift of 0.017 THz, and the second resonance mode has a shift of 0.016 THz, demonstrating the good frequency sensitivity of our sensor. The S (sensitivities) of the sensor were calculated at 875 GHz/RIU and 775 GHz/RIU, and quality factors FOM (Figure of Merit) are 26.51 and 18.90, respectively; and the minimum limit of detection is 0.04. By comparing with previous similar sensors, our sensor has better sensing performance, which can be applied to photon detection in the terahertz band, biochemical sensing, and other fields.

/pdf/design-of-ultra-narrow-band-graphene-refractive-index-sensor-15gyt2xt.pdf

Design of Ultra-Narrow Band Graphene Refractive Index Sensor

Two photonic crystal optical refractive index sensors have been proposed in this paper. These sensors can be used for detection of basal cell cancer. A rod-type square lattice of GaAs is used for this purpose. The sensor topologies are based on a photonic crystal ring-shaped resonator coupled to two and waveguides respectively. Instead of using ultra-high quality factor cavities for improving the sensitivity, the resonance profile is localized and concentrated on the analyte to achieve good distinction. A 13 nm cavity resonance frequency shift for normal and cancer cells is obtained for detection of basal cell carcinoma. Finite difference time domain method and plane wave expansion methods are used to simulate and analyze the structures. The proposed biosensors have a sensitivity equal to 720 and 638 nm/RIU. The simplicity of the design and its high sensitivity make it a suitable choice for bio-sensing applications.

Design of a label-free photonic crystal refractive index sensor for biomedical applications

In this paper, a high-resolution refractive index sensor is proposed based on a novel metal–insulator–metal plasmonic topology. The structure is based on a Si nano-ring located inside a circular cavity. It acts as an optical notch filter with a quality factor equal to 269. The proposed filter topology is numerically simulated using the finite difference time domain method. It is shown that the proposed filter can also act as a refractive index sensor with a sensitivity of 636 nm/RIU and a fairly high figure of merit (FoM) equal to 211.3 RIU−1. It is shown that the sensor can easily detect a refractive index change of ± 0.001 for dielectrics whose refractive index is between 1 and 1.2. For the refractive index range of 1.33 to 1.52, the maximum FoM of the sensor is 191 RIU−1. The simplicity of the design and its high resolution are the two main features of the proposed sensor which make it a good candidate for biomedical applications.

Design of a High-Resolution Metal–Insulator–Metal Plasmonic Refractive Index Sensor Based on a Ring-Shaped Si Resonator

A photonic crystal optical limiter with a sharp input-output characteristic curve is initially designed in this paper. Thereafter; using an optimized Y-junction, a new topology for an all-optical photonic crystal AND gate is proposed. The mentioned gate has a transition time less than 1 ps, a delay time less than 0.4 ps and occupies an area less than 100 μm2. The 1,550 nm input lasers should have a power equal to 10W to be able to trigger the switching mechanism. The photonic crystal used for this purpose is a two dimensional triangular lattice of holes in a GaAs substrate. PWE and FDTD methods are used to simulate the proposed structure. Time domain simulations confirm the switching mechanism of the proposed AND gate.

https://link.springer.com/content/pdf/10.1007%2Fs11082-011-9527-y.pdf

Design and simulation of an all-optical photonic crystal AND gate using nonlinear Kerr effect

In this paper, a novel nanoscale refractive index sensor topology, which incorporates a ring resonator containing circular tapered defects coupled to a metal-insulator-metal (MIM) plasmonic waveguide with tapered defects, is proposed. For the proposed design, the effect of introduction of defects on transmittance value, shape of magnetic field, and sensor parameters such as sensitivity (S) and figure of merit (FOM) are investigated numerically and simulated using finite-difference time-domain (FDTD) method. By optimizing the ring radius and selecting the appropriate waveguide width, we have achieved a maximum sensitivity of 1295 nm per refractive index unit (RIU) and a fairly high FOM equal to 159.6 RIU−1. The structure can be used as a high accuracy refractive index sensor for refractive indices ranging from 1 to 1.65. Due to the small size, wide detection range, and the high detection resolution of the proposed sensor, it is a good choice for integrated bio-sensing applications.

Mohammad Danaie

Papers

Design of a label-free photonic crystal refractive index sensor for biomedical applications

Design of a High-Resolution Metal–Insulator–Metal Plasmonic Refractive Index Sensor Based on a Ring-Shaped Si Resonator

Design and simulation of an all-optical photonic crystal AND gate using nonlinear Kerr effect

Design of a Refractive Index Plasmonic Sensor Based on a Ring Resonator Coupled to a MIM Waveguide Containing Tapered Defects

Realization of single-mode plasmonic bandpass filters using improved nanodisk resonators