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Light propagation inside half substractor for a Case #2 (X = 1 and Y = 0), b Case #3 (X = 0 and Y = 1), and c Case #4 (X = 1 and Y = 1)
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This paper reports a new design of a tunable optoelectronic half adder/subtractor. Two photonic crystal (PhC) ring resonators are used to realize the proposed structure. Several silicon rods surrounded by silica rods covered with graphene nanoshells (GNSs) form every PhC ring resonator. Setting the chemical potential of GNS with an appropriate gate...
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Fast and compact optoelectronic devices are highly sought after for applications in high-speed signal processing in optical communication networks. One approach to realizing such devices is through all-optical digital logic circuits. One of the main building blocks of such circuits is a decoder. In this work, we present a novel design for a tunable...
Citations
... Pakrai et al. (2022) developed an optical system using three ring resonators that can work as a combined half adder/half subtractor and obtained a maximum rise time of 3 ps. Naghizade and Saghaei (2021) developed a tunable optical half adder and half subtractor using two ring resonators covered by graphene nanoshells and reported a maximum response time of 0.8 ps. Fang and Tang (2022) designed all-optical half adder and half subtractor inside a single structure using photonic crystal based nonlinear cavities and reported a contrast ratio of 18.3 dB and a response time of 1.5 ps. ...
In this paper, the implementation of an integrated system of half adder and half subtractor based on 2D Si-air photonic crystal is proposed. The structure includes two input ports, one control port, and two output ports. When light is absent in the control port, the structure operates as a half adder and when light is present in the control port, it functions as a half subtractor. The operation of the structure is based on the phenomenon of constructive and destructive interference of light waves. The novelty of the proposed structure is that using a single control signal, both half adder and half subtractor operations can be realized. Since no nonlinear material has been used to design the structure, the power consumption of the structure is very low. Another advantage of the structure is that same materials have been used for all the rods which makes the fabrication process easier. The structure has been simulated by utilizing PWE and FDTD methods. Different performance parameters such as contrast ratio, rise time, delay time, fall time, response time, and bit rate for the designed structure have been obtained as 14.78 dB, 0.25 ps, 0.3 ps, 0.11 ps, 0.44 ps, and 2.27 Tb/s respectively. Due to its high contrast ratio, fast response time, high bit rate, and smaller dimension, the designed structure can be a promising candidate for realizing high speed optical integrated circuits.
... A half-subtractor and half-adder photonic crystal have been designed and simulated using two photonic crystal nanoring resonators [69]. The matching structure's nanoring resonators are made of a silicon rod surrounded by SiO 2 rods covered with graphene nanoshells (GNSS). ...
... The optical half-subtractor. (a) The schematic diagram of the proposed structure (b) time response for X = 1, Y = 0 (c) time response for X = 0, Y = 1 (d) time response for X = Y = 1[69]. ...
A half-subtractor is a digital circuit that subtracts two inputs and displays the result in two outputs. Photonic crystals (PhCs) are used in optical circuits, including en-coders, multiplexers, adders, subtractors, timers, counters, etc. This paper reviews and compares some of the all-optical half-subtractors and full-subtractors based on PhCs reported to date. We study physical parameters, including the arrangement of dielectric rods, rod radius, lattice constant, structure area, background material, and resonator type and illustrate the structure with a small size is suitable for integration in a photonic chip. Another crucial factor is the optical power difference between the two logic states of 0 and 1. A large difference between these two values increases the contrast ratio and reduces the detection error in the output. Delay time as a key parameter specifies that the input signal will leave the desired output after a few fem-toseconds. Linear structures have the lowest delay time, fall time, and rise time among compared structures. But on the other hand, non-linear structures have the highest amount of contrast ratio. In the recent papers, relatively favorable delay times are obtained, equal to 0.06, 0.1, and 0.85 ps, respectively. Also, the fall times are a small value and are equal to 0.05, 0.1, and 0.25 ps, respectively, and the rise times are equal to 0.1, 0.5, and 0.7 ps, respectively. Also, the contrast ratio values are high and acceptable which are equal to 25.88, 18.80, and 18.40, respectively.
... Photonic crystals (PCs) are artificial materials that are engineered to have a periodic structure on the scale of the wavelength of light (Yablonovitch 1994). They are designed in a way that creates a photonic band gap (PBG), a range of frequencies where the propagation of electromagnetic waves (including light) is forbidden (Yablonovitch 1993;Sani et al. 2020a;Naghizade and Saghaei 2021b). This ability to control the flow of light is analogous to the way semiconductors control the flow of electrons. ...
In this study, we introduce a highly sensitive pressure sensor utilizing a polymer-based photonic crystal (PC) slab. When pressure is applied, changes in the shape of air holes and the refractive index cause shifts in the sensor’s resonance wavelengths. We systematically optimize the structure by exploring various radii, enabling the selection of an optimal configuration for the photonic waveguide. Through simulations of the optimized design, we analyze its behavior in response to changing pressure on the sensitive surface. Employing finite-difference time-domain and plane wave expansion methods, we investigate the optical characteristics of the sensor. Our numerical findings demonstrate that the optimized sensor exhibits exceptional quality factor, transmission, and sensitivity values of 29,363, 0.98, and 0.021 µm/GPa, respectively. These results surpass those reported in previous studies involving PC-based structures, highlighting the significant advancement achieved in our approach.
... Graphenebased modulators are increasingly being integrated into silicon photonic (SOI) platforms (Shu et al. 2018;Bonaccorso et al. 2010;Rezaei and Shiri 2021). This integration enables the development of high-performance and low-power optical communication systems (Naghizade and Saghaei 2020, 2021a, 2021b, 2021cNaghizade et al. , 2023 Alden Mostaan and Saghaei 2021;Nayyeri Raad et al. 2023;Rezaei et al. , 2020. The combination of graphene's exceptional electro-optic properties and SOI's compatibility with existing semiconductor technology provides numerous advantages for optical modulators. ...
This paper presents a novel design of an optical electro-absorption modulator based on a hybrid plasmonic structure with a graphene layer on the generic InP platform. Graphene-based optical modulators have the potential to revolutionize the field of optical communications. They enable high-speed data transfer and facilitate advancements in quantum computing. Developing a highly compact modulator on the InP platform represents a significant objective for photonics researchers aiming to achieve large-scale photonic integration technology. In the proposed design, a metal layer on top of a ridge waveguide creates a hybrid plasmonic structure. At the same time, light modulation is accomplished by applying a bias voltage to the graphene layer. By manipulating the optical absorption properties through changes in the Fermi level of the graphene layer, calculations demonstrate a 3 dB bandwidth exceeding 70 GHz at λ = 1.55 μm for a 1 µm length. Furthermore, the impact of metal and SiO 2 dielectric layer thicknesses and chemical potential on the real part of the effective index, optical absorption, 3 dB bandwidth, extinction ratio, and insertion loss are quantitatively determined.
... This results in a gap in the frequency spectrum where photons cannot propagate through the material. The discovery of photonic bandgaps has led to the development of a wide range of novel photonic devices, including logic gates (Sharifi et al. 2016;Younis et al. 2014a;Fu et al. 2013;Ibrahim et al. 2003;Mondal et al. 2018Mondal et al. , 2022Goswami et al. 2022;Veisi et al. 2022Veisi et al. , 2021 Mohebzadeh-Bahabady and Olyaee 2019), filters (Hosseinzadeh Sani et al. 2020;Foroughifar et al. 2021aForoughifar et al. , 2021bSaghaei et al. 2022Prakash et al. 2018;Mondal et al. 2019a;Saghaei 2020a, 2020b), multiplexers and demultiplexers Alipour-Banaei et al. 2015a;Dangi et al. 2022), encoders and decoders (Monisha et al. 2018;Mehdizadeh et al. 2017;Yang et al. 2017;Chen et al. 2006;Parandin et al. 2018;Alipour-Banaei et al. 2015b;Haddadan et al. 2020;Maleki et al. 2020;Mondal et al. 2019b;Sharma et al. 2022;Naghizade et al. 2023aNayyeri Raad et al. 2023), comparator (Seraj et al. 2020;Parandin et al. 2022;Naghizade et al. 2023b), adders and subtractors Maleki et al. 2020;saleh Naghizade, H. Saghaei 2021;Sani et al. 2020;Naghizade and Saghaei 2021a, b;Goswami et al. 2021;Parandin et al. 2017Parandin et al. , 2021b, flip-flops (Zamanian-Dehkordi et al. 2018;Rao et al. 2020;Sethi and Roy 2014;Kumar et al. 2010), PhC fibers (Aliee et al. 2020;Ebnali-Heidari et al. 2012;Goswami et al. 2023;Saghaei and Van 2019;Ghanbari et al. 2500;Saghaei 2018;Raei et al. 2018;Kalantari et al. 2018 Beggs et al. 2009), sensors (Parandin et al. 2021a;Hosseinzadeh Sani et al. 2021;Liu and Salemink 2012;Nair and Vijaya 2010;Guo et al. 2019;Olyaee et al. 2016;Rabee et al. 2019;Cárdenas-Sevilla et al. 2011;Sultana et al. 2018;Sardar et al. 2020), converters (Naghizade and Saghaei 2021c, d) and so on that can be widely used in the PICs. These devices offer many advantages over traditional electronic-based devices, such as low-loss transmission and immunity to electromagnetic interference. ...
This paper proposes a novel approach for designing all-optical logic gates in a photonic crystal platform, utilizing an appropriate fluid infiltration technique. Considering a threshold of 26% input power for a logic zero, the proposed method can create four all-optical AND logic gates and three all-optical OR logic gates that can successfully perform the expected logical functions for an input light source with a central wavelength of 1.55 µm. The results of numerical simulations indicate that the minimum delay observed in AND gates is only 393 fs, while the minimum delay among OR gates is 1700 fs. The maximum delay observed in AND gates is 693 fs, and the maximum delay among OR gates is 3933 fs. These findings demonstrate that various logical functions can be achieved with minimal delays by injecting an appropriate fluid into the air holes of a fixed platform. The proposed method provides a promising development in producing more efficient and reliable Photonic Field-Programmable Gate Arrays (PhFPGAs), potentially replacing existing integrated circuit manufacturing methods. The simplicity and flexibility of the fluid injection method and the feasibility of fabricating such a platform with current technologies make this approach a significant advancement in developing PhFPGAs.
... By manipulating the electrons in graphene, integrated electro-optic devices can be modeled and designed. Different structures consisting of graphene on silicon (Si) or silica have been proposed for this purpose [43,[73][74][75][76][77]. In this work, we present the use of a GNS shell with a thickness of 5 nm coated around a silica rod. ...
... By manipulating the electrons in graphene, integrated electro-optic devices can be modeled and designed. Different structures consisting of graphene on silicon (Si) or silica have been proposed for this purpose [43,[73][74][75][76][77]. In this work, we present the use of a GNS shell with a thickness of 5 nm coated around a silica rod. ...
A logic comparator is a digital circuit comprised of numerous transistors on an integrated circuit that compares two binary numbers. Researchers have proposed various designs for implementing comparators using logic gates, but most are based on DC electrical signals, which suffer from slow switching speeds and high power consumption. This paper presents a novel design for a fast and tunable electro-optic single-bit comparator utilizing graphene-coated nanoshells (GNSs) in photonic crystal (PhC) ring resonators. The comparator's structure includes three inputs, three GNS-coated ring resonators, several waveguides for comparison, and three outputs created in a PhC microstructure in an area of 760 µm². A continuous-wave laser source centered at 1550 nm is applied to the first input to enable the proposed photonic chip. Two other inputs are utilized to apply electrical voltages, and the comparator's task is to compare them. The optical signal applied to the enable input port is directed to the corresponding output depending on the comparison result. We used the finite-difference time-domain method to study the light propagation inside the proposed structure to solve Maxwell's equations. Numerical simulations demonstrate that the designed structure has a very short delay time of 1.85 ps, faster than previously reported comparators, including electronic, optoelectronic, and all-optical comparators. The proposed comparator's rapid response, small area, and tunability make it an appropriate device for optical applications in photonic integrated circuits.
... The highest (CR) occur in [25] in a hexagonal shape lattice type with only OR-gate as in Table IV. Ref. [34] has the maximum (BR) in literature and [30] has the highest (CR) for the XOR-gate. The maximum size with 2 2 exist in [24] and [26] for both gates. ...
The OR-XOR-NOT gates are considered in this paper. They can be constructed in different topologies such as ring resonator, self-collimation, waveguide, and cavity-based structures. Linear and nonlinear materials are used to implement these gates in literature. In this paper, the proposed design is formed in a linear photonic crystal square lattice floor with ring resonator topology and interference based operation. By applying sensitivity analysis and by organizing the location of some rods; the OR-XOR-NOT gates are verified. Simultaneous operation, minimum area structure and high bit rate are the remarkable figures of merits for this design. The minimum size of 56.16 2 is obtained. The bit rates of 5.02 Tb/s, and 3.1 Tpbs are calculated for OR, and XOR respectively. As the NOT-gate operation is a part of the XOR; so, it can be verified in this paper. The phase shift between the input powers and their effect are examined carefully. The threshold power level is considered as 0.3. Comparative tables are organized for both gates based on ring resonator topology. The fabrication methods are discussed and evaluated. These structures are designed, simulated and optimized at 1.55 OR-XOR-NOT gates.
... All the available structures were built in a background of air except that proposed in [87] that has SiO 2 with refractive index of 1.45. Lithium Niobate (LiNbO3, LN) [89], Indium Phosphide, Chalcogenide glasses [86], GNS, and SiO 2 [90] are different materials that used to implement rods. Metal-dielectric was used to verify the operation as in [91]. ...
In this paper, different topologies were discussed and their effect on the design of photonic crystal applications was evaluated. They can be classified into four categories (i.e., ring resonator, self-collimation, waveguide, and cavity-based structures). The figure of merits of each topology and its impact on design modules were explained and compared for two different applications (i.e., half-adder and decoder). Finite difference time domain (FDTD) and plane wave expansion methods are the two numerical approaches that were used to analyze the proposed designs. The truth table for each application was introduced. Comparison tables were organized to discriminate the valued characteristics for each structure. Based on the extracted tables, the appropriate topology can be chosen for the required design application according to the needed characteristic.
This paper presents the design and optimization of a side-coupled photonic crystal nanobeam (1D PhC) cavity incorporating micro-ring resonators and a bus waveguide for efficient light coupling. The innovative design incorporates a parabolic taper function, ensuring gradual mode-gap modulation and robust light confinement. Through rigorous numerical simulations and optimization of key parameters—including the 1D PhC period, cavity center radius, taper delta radius, number of taper and mirror holes, waveguide width, ring radius, coupling gap distance, and material refractive index—we achieved a remarkable maximum Q factor of 2.5 × 105 at a wavelength of 1693.5 nm. This optimized configuration significantly enhances light-matter interaction, making it promising for applications demanding high-Q resonators.
