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One of the challenges in using integrated optical biosensors is their ability to operate in environments outside laboratories. This occurs, among other reasons, because suitable source coupling components are not considered at the design stage. In this work, a highly selective, compact and efficient in-coupling method is proposed with the aim to develop a genuine Point-of-care (PoC) platform. The proposed configuration consists of a single-mode fiber core placed in parallel and centered above an inverted non-linear taper, which can also be seen as a pigtailed input stage. These components are separated by the cladding of the taper that acts as a gap. In this setup, light is coupled from the fiber to the taper, which then becomes the core of a multimode waveguide. The coupled modes depend on the position of the fiber and the geometry of the taper. For interferometric biosensors, the power distribution between the modes is very important because each one reacts differently to the sample placed on the optical transducer. Therefore, the selectivity of the coupling stage affects the interferometric pattern and, consequently, the detection process. In the model presented in this work, the input is set as the fundamental mode (LP01) of the fiber. Since it is centered, only the even modes are excited in the taper. The width of the taper varies from 2 µm to 3 µm, in order to select only high-order modes, due to their large evanescent tails lead to highly sensitive biosensors. The non-linear format optimizes the design by dividing the entire taper into a cascade of linear sections. Those in which the coupling of the desired modes occurs are prioritized by increasing their lengths, thus making the transition smoother. Instead, the other sections maintain a reduced length. To select other modes or change the power distribution between them, one may just simply change the width of the taper and the length of the prioritized sections. In this work, a fiber-to-taper configuration of 8 mm length is presented, which couples 48% and 17% of the input power to TE8 and TE10 modes, respectively.

As the optical characteristics of several materials such as vanadium oxide (VO 2 ) and lithium niobate (LiNbO 3 ) exhibit electrostatic and/or thermal dependences, these materials can be exploited in the design of multicontrollable optical devices. We simulated the visible/near-infrared spectrums of the specular reflectances and absorptances of a bicontrollable metasurface absorber with pixelated meta-atoms. Each meta-atom is a 3 × 3 array of pixels, some patched with VO 2 , some with LiNbO 3 , some with copper, and the remaining unpatched. The VO 2 pixels provide thermal control, the LiNbO 3 pixels electrostatic control.

This article presents the comparative analysis of antennas for Ground Penetration Radars (GPR) that operate in the VHF/UHF band around 200 MHz. Three types of antennas are optimized to improve bandwidth, obtain a gain greater than 5 dB while analyzing their Half Power Beam Width-HPBW, and front to back levels. These antennas are candidates to be implemented on a 2×2 array for a double polarized GPR to improve its resolution and range. This radar conducts non-invasive explorations to obtain data from Caral’s archaeological center in the city of Lima, Peru. The geometry design, simulation results, and optimization of the antennas were calculated using the ANSYS-HFSS software. The simulation results have indicated that the Antipodal Vivaldi antenna showed better results than the Log Periodic Dipole Arrays and the DGS Vivaldi antennas.

The Genetic Algorithm (GA) is one of the most popular heuristic methods due to its natural and fast implementation. However, at the same time, it has the disadvantage of poor optimization. To improve performance, it’s necessary avoid stuck in local maximums throught choosing proper methods and parameters that vary for each application. In photonic devices, although the GA has been recently used to optimize passive silicon Y-branches, its performance is still trailing behind other optimization algorithms based on swarms, for instance. In this work, we present a new three-part heuristic method for optimizing Y-branches. We used the Finite-difference Time-domain (FDTD) method and the Particle Swarm Optimization (PSO) to generate an optimal data set as initial population for the GA. Considering an adequate population model, we demonstrate improvement in the performance for the design of a Y-branch through the GA. Next, we used a variation of a gradient-based search method to fine-tune the final parameters to find the absolute maximum. As a result, we produced new non-intuitive Y-branch devices with on-chip areas smaller than 2µm2 and excess loss down to 0.05 dB @1550 nm for the TE mode. A complete study of fabrication feasibility and uv-lithography typical fabrication errors and its effects on the bandwidth will be shown at the time of the conference. Our method will be compared against other widely-used heuristic methods in photonic device design in terms of number of iterations.

In this work, we analyze passive parameters for a band of 1500 to 1600 nm in microring resonators (MRRs). Such analysis can be vital for estimating an appropriate parameter design exploration with potential applications on Wavelength Division Multiplexing (WDM) solutions. Using a coupled mode theory-based method, we found optimal design spaces for MRRs with radii from 5 to 10 µm and bus-ring gap from 0.12 to 0.21 µm. For All-Pass MRRs, we found an optimal design space where the transmittances in the resonant frequencies are down to 8% in the Through port, while for the Add-Drop MRRs, we found an optimal design space where for transmittances in the Drop port are from 0.77 to 1. We also found optimal design spaces for Q-factors between 2000 and 3800. To find the optimal ring/radius and bus-ring gap values inside the design spaces, we use the particle swarm optimization technique. The data obtained with the exhibited work also shows a modal analysis for the supermodes formed by the cross-section of the bus-ring interface and the impact of UV-lithography common fabrication errors, even due to wafer die positioning. With the latter, our work provides a comprehensive design space exploration and helps designers to know the effect that typical structural fabrication errors will have on the passive resonance.

Aluminum nitride (AlN), which belongs to the family of the III-V semiconductors, is a material of great interest in the microelectronics industry due to its high decomposition temperature, good chemical stability, wide bandgap and CMOS compatibility. Moreover, AlN is known by its Pockels coefficients, which makes it very suitable for various non-linear optical devices. In this work, a study of a design space exploration of fundamental mode polarization in an AlN pedestal waveguide is proposed. The current work performs a dispersion analysis of this type of waveguide by varying the dimensions of the core and the pedestal. Lastly, electrode design for phase shifting analysis is also proposed. The data obtained with the exhibited work will allow the device designer to have a design space with light polarization control to stimulate the adequate electro-optic coefficient, with potential applications in modulators, switches, multiplexers, phase shifters, among others. A feasibility study will also be provided.

III-V materials with quantum wells or quantum dot active regions have proven to be relatively efficient devices for amplifying light. However, integration and scaling of many other functions are moving towards the development of ever more complex photonic integrated circuits (PICs). Assembling these devices into hybrid/heterogeneous PICs poses a challenge in terms of bandwidth and footprint. In this work, we propose a Particle Swarm Optimized methodology to generate non-intuitive structures that couple light vertically from a III-V platform to a silicon-on-insulator chip. By designing heuristically optimized III-V and silicon tapers, we can overcome the limitations of typical linearly-varying spot-size converters in terms of footprint, without sacrificing bandwidth. Furthermore, the optimization parameters are adjusted to fit the usual design rule constraints that are ready for mass production, namely UV-lithography limits.

Coupling between monomode silicon waveguides and Ge photodetectors is challenging due to the size mismatch between both components. This work proposes a non-linear tapered coupling device to couple light from a silicon on insulator waveguide to an SOI Ge photodetector. For our 32.1 µm non-linear spot-size converter, the simulated transmission coefficients in the SCL band for 1550 nm, 1460 nm, and 1625 nm wavelength are -0.0113, -0.059, -0.0092 dB, respectively; while state of the art linear spot-size converters of the same transmission coefficients are around 211% bigger.

Silicon modulators paved the way for silicon photonics to take control of optical interconnects. Since its popularization, most works use the 1-D diode model approximation to design the horizontal PN junction, which estimates the modulator bandwidth and efficiency. Some works do not even consider the effects of fringe capacitance, alleging that the junction’s dimensions are large. The 1-D model is suitable for vertically uniform PN junctions. However, there are essential deviations for the typical rib waveguide used in most horizontal-junction silicon modulators. Our work aims to quantify such deviations incorporating details from 2D model simulations and offer a corrected 1-D model for estimating modulation bandwidth. This study was carried out as follows: firstly, we incorporated an improved scheme for phase shifting and loss for different junction locations and widely used doping concentrations. Next, we analyzed the generation-recombination effects and their impact on the depletion width at the top and bottom of the waveguide. We calculated the depletion width via the 1-D model and the two-dimensional Poisson’s equation finite-element calculation for the rib and identified an important mismatch. Lastly, we propose and demonstrate an accurate equivalent circuit with our 1-D model corrections. Our model considers the total depletion capacitance, the fringe capacitance, the capacitance due to the wider depletion widths at the top and bottom surfaces of the diode, and other capacitive effects at the border of the rib as a result of high reverse bias. We found that although the 1-D model is well-suited for small reverse biases, higher voltages and extreme junction locations affect the bandwidth’s estimation dramatically.

Silicon photonics is the leading platform for pho-tonic integrated circuits (PICs) because of its low fabrication cost and a small area on-chip, which allows the forefront of the industry to develop low-energy consuming devices. For the implementation of PICs, among passive devices, the most used because of its functionality is the power splitter. Y-junctions are power splitters that are compact and can deliver relatively wide-band frequency responses. In order to respond to the current demands of silicon photonics foundries, this work proposes a method based on the Particle Swarm Optimization to design always-feasible and mass-production oriented Y-junctions. We have achieved transmittances above 49%, and a flat frequency response in the SCL optical communications band.

We report the comparison between three optimization methods used for the design of Y-junction in terms of convergence velocity, maximum transmitted power and fabrication feasibility. The optimization techniques include Particle Swarm Optimization, Shrinking Box algorithm and Steepest Ascent algorithm. we demonstrate transmittance values of 49% in the case of the splitter and near 96% in the case of the combiner with areas on chip down to 2.05 μm2. The practical application of this work is to design compact, low-loss and wavelength independent splitters and combiners for sub-micron silicon-on-insulator(SOI) photonic integrated circuits, compatible with typical commercial standard microfabrication processes.

Thin-film polymer-on-silicon modulators are efficient devices which have shown potential for integration scalability due to chromophore-based electro-optic constant engineering. Assembling them into hybrid silicon-photonics integrated circuits poses an interesting challenge in terms of bandwidth and footprint. Accordingly, we propose the first, to the best of our knowledge, sub-wavelength silicon tapered structures to couple light vertically from a polymer film platform to a silicon-on-insulator chip. By designing horizontally tapered and longitudinally segmented waveguides in the subwavelength regime to couple light vertically, we can overcome the bandwidth limitations of grating couplers while still have considerable footprint reduction when compared to continuous linearly tapered evanescent vertical coupling. Our simulation results show that silicon-on-insulator-compatible linearly tapered segmented waveguides offer losses bellow 0.5 dB in the C and L bands with four times smaller coupling length than their continuous counterpart. Preliminary studies show that there is good horizontal misalignment tolerance up to 1.5 micrometers.

Optical antennas/nanoantennas are optical elements that have gained highlight in this decade and have potential application in several branches of photonics/plasmonics, such as, optical sensors, lasers, solid state lighting, photovoltaics, microscopy, etc. Additionally, the dipole nanoantennas have been the antennas elements mostly studied in proposals for those applications and, in special, for free-space communication based on plasmonic circuits. Here we report some advantages of dielectric resonator nanoantennas (DRNAs) as elements for coupling light to plasmonic-based circuits. Fundamental antenna parameters such as reflection coefficient, gain, efficiency, among others, are evaluated and its advantages are highlighted for nanophotonics applications. A study about an optical link for circuits based on metal-dielectric-metal-dielectric (MDMD) nanostrip waveguides operating at the central wavelength of λ0 = 1.55 μm is evaluated. We studied the coupling of near- and far-fields of a DRNA matched to an MDMD nanostrip waveguide. The results show the advantage of it as an element for optical coupling from/to free-space as well as to establish a wireless optical link for inter-chip communication.