Abstract: Activation functions (AFs) are integral in enabling convolutional neural networks (CNNs) to perform image classification and recognition effectively. Here, we propose a new AF called "Einstein"— a novel, piecewise, and dynamic AF defined by parameter r. Einstein is inspired by our earlier work on analogies with Einstein's theory of special relativity, whose equation "morphs to its present form" when we apply it to AF. Our goal is to optimize Einstein by measuring its performance accuracies under CNN for different values of r. Einstein outperforms well-established AFs, like (i) Tanh and (ii) Leaky ReLU when r-value is from 0.80 to 1.00, and (iii) ReLU when r-values are 0.93, 0.96, and 1.00.

Abstract: We report the simulation, fabrication, and initial characterization of a hybrid double photonic microring resonator that combines one cross-coupling and one direct-coupling mechanism. Cross-coupling mechanism involves the physical interconnection of some ports, while in the direct-coupling mechanism, interconnection ports are evanescently coupled across a gap. We simulated the two hybrid architectures using Ansys Lumerical MODE, a leading-edge software for designing and analyzing integrated and fiber-optic devices. The resonators were fabricated at the Nanophotonic Technology Center in the Polytechnic University of Valencia, Spain, using state-of-the-art electron-beam lithography techniques. We performed preliminary characterization and observed both Coupled Resonator Induced Transparency (CRIT)-like effect. This work sets the stage for future experimental validation and potential applications in optical communication and quantum computing systems.

Abstract: We report on the design and simulation of an optical All-Pass Filter (APF) which is a passive photonic chip using a pulley-type, microring resonator (MRR) configuration using a Finite-Difference Time-Domain (FDTD) solver from the Lumerical MODE. The main challenge is to reduce optical losses. We analyze its main properties and performance by optimizing the parameters of the device that include (i) varying the gap, (ii) coupling length, and (iii) the ring radius. The data measured from the parameter sweeps are the optical transmission graphs. The main properties are free spectral range (FSR) and full width at half maximum (FWHM).  Several indications of optical losses were observed from the simulation graph results. The PIC design is fabricated using E-beam lithography.

Abstract: We present a novel framework referred to as Concept Connectivity that aids in educating and engaging students by presenting the topic of the Special Theory of Relativity (STR) in a coherent and unified manner. It uses different analogue implementations of the STR coming from seemingly distinct fields of study such as (i) Optics, (ii) Photonics, and (iii) Electronics to connect not only to the concepts of the STR but to the various concepts from these different fields. In these analogue implementations, the fundamental characteristics of the different STR phenomena can be mimicked in many different ways ...

Abstract: We report two new behaviors of the recently reported crisscross-coupled microring resonator structure, namely (i) ‘ultraslow light’ propagation under symmetric parameter conditions, and (ii) a “flipping property” in the group delay under asymmetric parameter conditions. These properties can be utilized in numerous optical-based applications.

Abstract: Recently, we reported a general technique that uses a “cross-coupling structure” as a new vehicle to manipulate the resonance features of the coupled resonators. The technique is important for the (i) search for new optical analogues of Quantum Coherence Effects (QCEs) and (ii) generation of fresh and richer optical behaviors of the coupled resonators that could open future applications in optical fiber communication. Here, we review two new configurations based on this technique. The first configuration uses a modified standard double resonator (SDR) which we refer to as Cross-coupled SDR (CC-SDR). It is a new analogue circuit of QCE that generates a new QC phenomenon we call Cross-coupled Resonator Induced Shifted Absorption (CRISA). It is the first-time a cross-coupled structure has been suggested in studying QCE. Its core mechanism is due to its “cross-coupling structure”. Second, we present a modified coupled ring reflector (CRR) configuration where its original directional couplers (DCs) are replaced with cross-coupler(s) to connect the two ring resonators. We refer to it as crisscrossed-assisted CRR (or X-CCR). We review the unique characteristics of these two configurations and discuss their applications as optical devices.