A metallic hole array of a rectangular converging-diverging channel (RCDC) shape exhibits extraordinary transmission for wavelengths larger than the periodicity of the holes. We use a three-dimensional (3D) finite element method to analyze the transmission characteristics of two-dimensional metallic hole arrays (2D-MHA) with RCDC. For a straight channel MHA, when the aperture size is reduced, the transmission peaks have a blue-shift. The same result is observed for a smaller gap throat for the RCDC structure. For the rectangular holes with a high length-width ratio, a similar blue-shift in the transmission peaks as well as a narrower full width at half maximum (FWHM) are observed. The asymmetry from the rectangular shape gives this structure high selectivity for light with different polarizations. Furthermore, the RCDC shape gives extra degrees of geometrical variables to 2D-MHA for tuning the location of the transmission peak and the FWHM. Tunable extraordinary transmission via changing temperature of a porous metallic layer on top of a thin layer of dielectric strontium titanate (STO) is then studied. The metallic layer has a through-hole array and each hole has a circular converging-diverging channel (CDC) shape, which induces the excitation of surface plasmon polaritons (SPPs) and then results in a controllable extraordinary optical transmission in the terahertz (THz) frequency range. We use a three-dimensional (3D) finite element method to analyze the transmission characteristics of the structure. Location and magnitude of the transmission peaks can be adjusted by the hole size, converging angle, and thicknesses of metal and STO layers. Remarkably, the suggested structure presents a strong transmission dependency on temperature, which offers a new approach to actively and externally tune the transmission. Currently, the performances of thin film solar cells are limited by poor light absorption and carrier collection. In this research, large, broadband, and polarization-insensitive light absorption enhancement is realized via integrating with unique metallic nanogratings. Through simulation, three possible mechanisms are identified to be responsible for such an enormous enhancement. A test for totaling the absorption over the solar spectrum shows an up to ~30% broadband absorption enhancement when comparing to bare thin film cells. Overall performance of a thin film solar cell is determined by the efficiency of conversing photons to electrons that include light absorption, carrier generation and carrier collection processes. Photon management via hybrid designing has been emerging as a powerful means to further boost the conversion efficiency. Here a new nanograting solar cell design, which can be universal and a new solar cell platform technology, is proposed with goals to achieve large enhancement on broadband light absorption and carrier generation, most importantly, under the much reduced usage of active and non-earth-abundant materials. A test for the short circuit current density in CuIn[subscript x]Ga([subscript 1-x])Se₂ (CIGS) thin film solar cells shows an up to ~250% enhancement when comparing to the corresponding bare thin film cells. Besides that, by placing metal strips on top of the nanograting, which act as the top electrode, this design is able to reduce the use of non-earth-abundant materials such as indium that is normally used in both active and transparent conducting materials. / text

The objective of the present dissertation is to advance the science and engineering of metal-dielectric thin-film structures for ultrafast all-optical applications. The research presented consists of three parts: first, the linear and nonlinear optical (NLO) properties of Au and Ag/Au bilayer metallic thin films are comprehensively studied; then the design and properties of a novel nonlinear device structure are presented and finally an ultrafast all-optical shutter is developed and applications are discussed. In the first part, this study describes the linear and NLO properties of bilayer metallic films and shows that they can be tuned by controlling the mass-thickness ratio between Au and Ag. The combined properties of these bilayers are attractive for active plasmonic applications and nonlinear optical filters. Detailed physical models describing the linear and NLO response of Au and Ag/Au bilayers are presented and compared with experiments. In the second part, these models are used to optimize the NLO response of a novel Au-based NLO device. With only four layers, this novel device strongly amplifies the NLO response of the component Au thin film. NLO devices with broad spectral and angular bandwidths in the visible spectral region are demonstrated. The narrow band dependent NLO response of the NLO device is shown to lead to all-optical controls of high peak-power optical signal pulses. Finally, the NLO device technology is integrated into a novel ultrafast all-optical shutter, which allows temporal opening windows (the time shutter remains open) as short as a few ps. Ultrafast all-optical shutter potentially can temporally shape high peak-power nanosecond optical pulses, which could benefit biomedical and micromachining applications. Other possible optical applications such as short electron, X-ray pulse generations, ultrafast photography, and biomedical imaging will also be discussed.

Neste trabalho apresentamos uma nova técnica para a medida da rotação da polarização da luz por uma substância que possui atividade óptica. O sistema utiliza um LED, dois polarizadores, um prisma de vidro semicilíndrico, uma cubeta, uma CCD e um computador para análise de dados. Luz proveniente do LED passa pelo primeiro polarizador, cujo eixo de transmissão se encontra a 45°, e incide no prisma pelo lado semicilíndrico, ocorrendo reflexão na sua base, num ângulo próximo do ângulo crítico. Devido ao tamanho finito do feixe e o formato curvo da superfície do prisma, vários ângulos de incidência são observados na base da lente semicilíndrica. A luz refletida passa então pela cubeta e depois por um analisador, cujo eixo se encontra paralelo ao primeiro polarizador, e então o sinal é captado pela CCD. De forma alternativa, a cubeta pode ser posicionada após o primeiro polarizador, antes do prisma. Quando a cubeta é preenchida com água, observa-se na CCD uma interferência destrutiva exatamente no ângulo crítico caracterizado por um mínimo de intensidade nesse ângulo. Se uma substância opticamente ativa é utilizada para preencher a cubeta, a posição desse mínimo é alterada dependendo do ângulo de rotação da polarização imposto pela substância. Uma calibração é necessária e pode ser feita utilizando-se soluções de concentração conhecida de sacarose ou frutose, por exemplo. O aparato obtido foi utilizado para medir a rotação causada por uma amostra normal (0,26 g/ml) de soluções de sacarose e frutose e apresenta uma precisão de 0,04°. Equivalentemente, a precisão em concentração é de 0,001 g/ml ou aproximadamente 0,1% (m/m). Isso corresponde a uma precisão que é uma ordem de grandeza acima dos aparelhos comerciais e técnicas mais comuns utilizadas atualmente. Em contrapartida, o custo da montagem experimental é duas ordens de grandeza menor que os mesmos aparelhos comerciais. A produção de uma gama de ângulos de incidência devido à focalização na superfície cilíndrica do prisma substitui a necessidade de se produzir rotação no eixo de polarização do analisador após a passagem da luz pela amostra opticamente ativa, como ocorre em alguns aparelhos comercializados. Este dispositivo, por ser de baixo custo, compacto e de fácil manuseio, é de grande importância porque pode ser utilizado na indústria sucroalcooleira para a medida da quantidade de sacarose em cana e também na indústria farmacêutica para a identificação de substâncias opticamente ativas dextrogiras ou levógiras. / In this thesis we present a novel technique for measuring light polarization rotation caused by an optically active substance. The system is composed by a LED, two polarizers, a semi cylindrical glass prism, a cuvette, a linear CCD camera and a computer for data analysis. Light from the LED passes through the first polarizer, whose transmission axis is set at 45°. After that, the linear polarized light enters the prism by the semi cylindrical face, occurring reflection in the flat face at critical angle approximately. Several incidence angles are accessed due to the beams finite size and the shape of the semi cylindrical lens. The reflected light passes through the cuvette and then through the analyzer, whose transmission axis is set parallel to the first polarizer. Finally, the light is detected by the CCD. When the cuvette is filled up with water, a destructive interference at the critical angle is observed, characterized by a narrow valley centered at this angle. If the cuvette is filled up with an optically active substance, the center of this valley is shifted depending on the substance, its concentration and the optical path travelled by the light in the substance. A calibration is needed and is performed using a set of solutions of known concentrations. Our apparatus was used to measure the angle rotation caused by a normal solution (0,26 g/ml) of sucrose and fructose solutions and has a precision of 0,04°. It corresponds to a precision that is one order of magnitude above most used commercial apparatus and developed techniques. In contrast, the cost of our experimental setup is two orders of magnitude less than the same commercial devices. The production of a range of angles of incidence due to focusing on the cylindrical surface of the prism replaces the need of producing a rotation of the analyzer polarization axis after the light passes through the optically active sample, as it happens in some commercial devices. Since this device has a low cost, is compact and easy to handle, it may be of great importance for applications in the pharmaceutical industry to identify enantiomers, and in the sugar industry for measuring sugar content in sugar cane juice.

Dispositivos fotônicos têm estado continuamente no foco das pesquisas científicas, particularmente em aplicações para comunicações ópticas e sensoriamento. Por outro lado, as dimensões desses dispositivos são restringidas pelo limite de difração de Abbe. Esse limite tem se mostrado como o grande gargalo no desenvolvimento de novas tecnologias em microscopia óptica, litografia de projeção óptica, óptica integrada, e armazenamento óptico de dados, por limitar as dimensões e a capacidade de integração destes dispositivos. Felizmente, a \"plasmônica\" surgiu como um novo campo de estudo, possibilitando a superação dessa limitação por meio da propagação da luz em modos de plasmon-poláritons de superfície - SPP (Surface Plasmon Polariton). De maneira simplificada, SPPs são campos eletromagnéticos confinados em regiões menores que o comprimento de onda da luz. A geração de SPP ocorre por meio da excitação coletiva de elétrons na interface entre dois meios, metal-dielétrico, que se acoplam com a onda eletromagnética incidente. Pesquisadores logo perceberam que guias de onda baseados em SPP poderiam transportar a mesma banda de informação que um dispositivo fotônico convencional e serem tão localizados quanto dispositivos eletrônicos (elétrons têm maior capacidade de confinamento que fótons). Dessa maneira, alterando a estrutura da superfície de um metal, as propriedades dos SPPs - em particular sua interação com a luz - podem ser manipuladas, oferecendo potencial para o desenvolvimento de novos tipos de dispositivos fotônicos. Com isso, nanoestruturas capazes de guiar, dividir ou mesmo sintonizar a luz tornaram-se realidade. No presente trabalho, o fenômeno de geração de SPPs é estudado teoricamente e aplicado na modelagem de diversas estruturas de interesse científico e tecnológico, tais como filtros de cavidade ressonante e ressoadores em anel. O objetivo principal é a obtenção de estruturas capazes de filtrar ou sintonizar comprimentos de onda, minimizando as perdas ao máximo. Com isso, espera-se estender e explorar ainda mais o leque de possíveis aplicações. / Photonic devices have continuously been in the focus of scientific research, particularly for optical communications and sensing applications. On the other hand, the dimensions of these devices are well known to be limited by the Abbe\'s diffraction limit. This limit has been the major bottleneck in developing new technologies in optical microscopy, lithography projection optics, integrated optics, and optical data storage, as it limits the size and ability to integrate these devices. Fortunately, the field of \"Plasmonics\" has emerged and devices whose dimensions overcome the difraction limit have now become reality. This is possible with the propagation of light in the form of Surface Plasmon Polariton - SPP that, in a simplified way, is an electromagnetic field confined in regions smaller than the wavelength of light. SPP occurs via collective excitation of electrons at the interface between two media, metal-dielectric, as a result of the coupling with an incident electromagnetic wave. Researchers soon realized that waveguides based on SPP could carry the same band of information as that of a conventional photonic device and yet be as localized as electronic devices (electrons have a greater capacity for confinement than photons). Thus, changing the structure of the surface of a metal, the properties of SPPs - in particular its interaction with light - can be manipulated, offering potential for the development of new types of photonic devices. Thus, nanostructures capable of transferring, guiding, splitting, or even tuning the light have now become reality. In this work, the phenomenon of generation of SPPs is theoretically investigated and applied to various structures of scientific and technological interest, such as filters and cavity resonators. The main objective is to obtain structures that are able to filter or tune wavelengths, minimizing losses as much as possible. As a result, we expect to extend and explore even further the range of possible applications.

The full complex, spatial modulation of light at high frame rates is essential for a variety of applications. In particular, emerging techniques applied to scattering media, such as Digital Optical Phase Conjugation and Wavefront Shaping, request challenging performance parameters. They refer to imaging tasks inside biological media, whose characteristics concerning the transmission and reflection of scattered light may change over time within milliseconds. Thus, these methods call for frame rates in the kilohertz range. Existing solutions typically offer frame rate capabilities below 100 Hz, since they rely on liquid crystal spatial light modulators (SLMs). We propose a diffractive MEMS optical system for this application range. It relies on an analog, tilt-type micro mirror array (MMA) based on an established SLM technology, where the standard application is grayscale amplitude control. The new MMA system design allows the phase manipulation at high-speed as well. The article studies properties of the appropriate optical setup by simulating the propagation of the light. Relevant test patterns and sensitivity parameters of the system will be analyzed. Our results illustrate the main opportunities of the concept with particular focus on the tilt mirror technology. They indicate a promising path to realize the complex light modulation at frame rates above 1 kHz and resolutions well beyond 10,000 complex pixels.

[ES] La fotónica de microondas, la cual une los mundos de la ingeniería de radiofrecuencia y la optoelectrónica, ha generado un gran interés en las últimas décadas. Su valor añadido se deriva del hecho de que, por un lado, permite la realización de funcionalidades clave en los sistemas de microondas que son complejas o directamente imposibles en el dominio de la radiofrecuencia. Por otro lado, crea nuevas oportunidades para los sistemas y redes de información y comunicación. Por lo tanto, la fotónica de microondas se utiliza para habilitar funciones especializadas como generación de señales de alta frecuencia, modulación, procesamiento de señales, particularmente en aplicaciones de comunicación, radar y detección. En el contexto de la fotónica programable, la versatilidad surge al permitir la manipulación dinámica de las señales de luz, haciéndolas adaptables para propósitos genéricos a través de redes ópticas, computación óptica, óptica adaptativa, investigación y desarrollo y fotónica cuántica. Por lo que, proporciona una plataforma flexible para aplicaciones ópticas, mostrando funciones complementarias a la tecnología fotónica moderna. Por lo tanto, los circuitos integrados fotónicos programables proponen y prometen ser una solución para competir con diseños específicos de aplicaciones. Sin embargo, las demostraciones actuales y las pruebas de concepto solo han integrado un número limitado de componentes y representan circuitos de complejidad pequeña y moderada. Este trabajo tiene como objetivo responder a las preguntas relacionadas con la escalabilidad del sistema y la evolución de futuros circuitos integrados fotónicos programables. El análisis y propuesta de soluciones constará de dos partes principales: la primera estudiará la escalabilidad de los circuitos programables en términos de integración de sistemas, incluyendo un estudio exhaustivo de las interfaces ópticas. En segundo lugar, debido a la necesidad de compensación de pérdidas que surge al utilizar fotónica integrada, consideraremos el rendimiento de modelos analíticos de fotónica de microondas de extremo a extremo con enlaces amplificados (balance de potencia óptica, ruido de señal, indicadores clave de rendimiento de enlaces fotónicos de microondas y consumo de energía). Una vez completado, utilizaremos diseños de complejidad moderada para evaluar nuestros estimadores de rendimiento tanto para el procesamiento de señales ópticas como para aplicaciones fotónicas de microondas. / [CA] La fotònica de micrones, la qual uneix els mons de l'enginyeria de radiofreqüència i l'optoelectrònica, ha generat un gran interés en les últimes dècades. El seu valor afegit es deriva del fet que, d'una banda, permet la realització de funcionalitats clau en els sistemes de microones que són complexes o directament impossibles en el domini de la radiofreqüència. D'altra banda, crea noves oportunitats per als sistemes i xarxes d'informació i comunicació. Per tant, la fotònica de microones s'utilitza per a habilitar funcions especialitzades com a generació de senyals d'alta freqüència, modulació, processament de senyals, particularment en aplicacions de comunicació, radar i detecció. En el context de la fotònica programable, la versatilitat sorgeix en permetre la manipulació dinàmica dels senyals de llum, fent-les adaptables per a propòsits genèrics a través de xarxes òptiques, computació òptica, òptica adaptativa, recerca i desenvolupament i fotònica quàntica. Pel que, proporciona una plataforma flexible per a aplicacions òptiques, mostrant funcions complementàries a la tecnologia fotònica moderna. Per tant, els circuits integrats fotònics programables proposen i prometen ser una solució per a competir amb dissenys específics d'aplicacions. No obstant això, les demostracions actuals i les proves de concepte sol han integrat un nombre limitat de components i representen circuits de complexitat xicoteta i moderada. Aquest treball té com a objectiu respondre a les preguntes relacionades amb l'escalabilitat del sistema i l'evolució de futurs circuits integrats fotònics programables. L'anàlisi i proposta de solucions constarà de dues parts principals: la primera estudiarà l'escalabilitat dels circuits programables en termes d'integració de sistemes, incloent-hi un estudi exhaustiu de les interfícies òptiques. En segon lloc, a causa de la necessitat de compensació de pèrdues que sorgeix quan s'utilitza fotònica integrada, considerarem el rendiment de models analítics de fotònica de microones d'extrem a extrem amb enllaços amplificats (balanç de potència òptica, soroll de senyal, indicadors clau de rendiment d'enllaços fotònics de microones i consum d'energia). Una vegada completat, utilitzarem dissenys de complexitat moderada per a avaluar els nostres estimadors de rendiment tant per al processament de senyals òptics com per a aplicacions fotòniques de microones. / [EN] Microwave photonics brings together the worlds of radiofrequency engineering and optoelectronics and it has attracted great interest in the last few decades. It added value stems from the fact that, on one hand, it enables the realization of key functionalities in microwave systems that either are complex or even not directly possible in the radiofrequency domain. On the other hand, it creates new opportunities for information and communication systems and networks. Hence, microwave photonics is used to enable specialized functions such as high-frequency signal generation, modulation, and signal processing, particularly in communication, radar, and sensing applications. In the context of programmable photonics, versatility emerges by allowing dynamic manipulation of light signals, making them adaptable for generic purposes across optical networks, optical computing, adaptive optics, research and development, and quantum photonics. Then, it provides a flexible platform for optical applications, showcasing their complementary roles in modern photonics technology. Hence, programmable photonic integrated circuits have been recently proposed and promise to be a solution to compete with application-specific designs. However, current demonstrations and proof-of-concepts have only integrated a limited number of components and represent small and moderate-complex circuits. This work aims to answer the questions dealing with the system scalability and evolution of future programmable photonic integrated circuits. The analysis and proposal of solutions will include two main parts: the first one will study the scalability of programmable circuits in terms of system integration, including a comprehensive study of optical interfacing. Secondly, due to the need for loss compensation that arises when using integrated photonics, we will consider the performance of end-to-end analytical microwave photonics models with amplified links (optical power budget, signal noise, microwave photonic links key performance indicators, and power consumption). Once completed, we will make use of moderate complexity designs to evaluate our performance estimators for both optical signal processing and microwave photonic applications. / Sánchez Gomariz, E. (2024). Scalability Analysis and Designs for Large-Scale Programmable RF-Photonic Integrated Circuits: Modelling, Design and Implementation [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/202894

No description available.

<p>Management of incoming solar radiation and use of the sky as an ultimate heat sink are technological imperatives as climate change shifts our reliance from fossil fuels to sustainable sources.  Selective solar absorbers are a possible route for solar harvesting as they collect the incoming radiation for process heat or space heating.  Here, improvement in the performance of selective solar absorbers via photon recycling is investigated using a stepped index rugate filter.  The final proposed filter when integrated with a high vacuum selective solar absorber could see an improvment in solar-thermal conversion efficiency from 13% to 30.6%. Then, a frequency selective optical filter is fabricated with uses including improvement of radiative coolers.  The measured optical characteristics are compared with simulation data and found to match well.</p> <p><br></p> <p>The shift to sustainable sources of electricity will require an expansion of the electrical grid.  The backbone of the grid for converting high voltage AC to DC, and vice versa, is power electronics.  The current state-of-the-art technology is GaN HEMTs, but GaN MISHEMTs are poised to replace them since MISHEMTs reduce the gate leakage current; a deficiency of the GaN HEMT architecture.  First, time dependent dielectric breakdown in GaN MISHEMTs is investigated using concurrent electrical and thermoreflectance methods.  A susceptibility in the MISHEMT architecture is found and possible solutions are proposed.  Then, liquid cooling of GaN HEMT PAs is explored by demonstrating integration of an X-band front end module, printed circuit board, and fluid manifold.  The integration shows great promise as two-phase cooling performance improved with increasing power dissipated, while single-phase cooling performance degraded.</p>

<p dir="ltr">Two-dimensional (2D) perovskite semiconductors are an emerging family of hybrid materials featuring a built-in quantum well architecture which has gained much interest due to its potential as a promising candidate for next-generation photovoltaic and optoelectronic applications. To successfully integrate 2D perovskites as efficient devices, it is imperative that a thorough understanding of the fundamental properties these materials possess and how their complex heterostructures behave is established. However, to date, the synthetic challenges regarding high-quality crystals of these materials due to the structural complexity and the hybrid nature have impeded further progress in this area. Thus, we demonstrate a general method to construct tunable 2D organic semiconductor-incorporated perovskites (OSiP) by simultaneously manipulating slab thickness of the inorganic layers and conjugation length of the organic substituents. The energy band offsets and exciton dynamics at the organic-inorganic interfaces were elucidated using computational means and ultrafast spectroscopy, while lattice dynamics were quantified via temperature-dependent spectroscopy and X-ray diffraction studies. Results show that longer and more planar π-conjugated organic ligands induce a more rigid inorganic crystal lattice, which leads to suppressed exciton-phonon interactions and superior optoelectronic properties such as efficient lasing.</p><p dir="ltr">Furthermore, understanding ion migration in two-dimensional (2D) perovskite materials is key to enhancing device performance and stability as well. However, prior studies have been primarily limited to heat and light-induced ion migration. To investigate electrically induced ion migration in 2D perovskites, we construct a high-quality single crystal 2D perovskite heterostructure device platform with near defect-free van der Waals contact. While achieving real-time visualization of directional ion migration, we also uncover the unique behavior of halide anions inter-diffusing towards the opposite direction under prolonged bias. Confocal microscopy imaging reveals a halide migration channel that aligns with the crystal and heterojunction edges. After sustained ion migration, stable junction diodes exhibiting up to ~1000-fold forward to reverse current ratio are realized. Unraveling the fundamental properties of 2D OSiPs as well as ion migration in 2D perovskite heterostructures paves the way towards stable and efficient devices.</p>

Este trabalho tem por objetivo a extensão de métodos numéricos baseados em diferenças finitas no domínio do tempo (FDTD) e no domínio da freqüência (FD-BPM) para a simulação da propagação de ondas eletromagnéticas em materiais com propriedades ópticas diversas, por exemplo, isotrópicos, anisotrópicos, lineares, não-lineares, bem como a combinação destes em uma mesma estrutura. Inicialmente foram elaborados formalismos bidimensionais (FDTD e FD-BPM), dos quais foram investigados modos com polarização TM (Magnético Transversal) que se propagam em estruturas planares magnetoópticas/não-lineares/lineares. Esta polarização foi escolhida tendo em vista o campo magnetostático dc adotado, o qual possibilitou a observação do fenômeno não-recíproco associado ao não-linear simultaneamente. Por outro lado, é bem sabido que o método FDTD é computacionalmente muito intensivo. Portanto, um grande esforço foi dedicado aos formalismos no domínio da freqüência, os quais foram implementados em duas e três dimensões. Este último foi estendido para um formalismo totalmente vetorial, capaz de simular modos híbridos ou até mesmo a transferência de energia entre modos de polarizações ortogonais. Isto nos permitiu investigar geometrias ainda mais complexas, tais como um isolador óptico baseado em um guia de onda tip rib utilizando material magnetooptico. Adicionalmente, fenômenos de natureza complexa, tais como a dinâmica dos condensados de luz em materiais com não-lineares do tipo Kerr com saturação, também conhecidos como meios não-lineares cúbico-qüínticos, foram investigados pela primeira vez com um formalismo vetorial. Finalmente, métodos numéricos capazes de considerar qualquer combinação de materiais com propriedades ópticas distintas (linear e/ou não-linear e/ou magnetoóptico) são uma ferramenta extraordinária para a comunidade científica para o projeto de novos dispositivos ópticos, bem como a investigação de novos efeitos físicos com vistas à aplicações em computação óptica, que podem resultar em um menor e mais eficiente número de componentes para sistemas de comunicações ópticos. / This work introduces three improved formalisms for the analysis of electromagnetic wave propagation through materials with distinct optical properties, i.e., isotropic, anisotropic, linear, nonlinear, or any combination of them. Two finite difference approaches were extensively investigated in this work for this purpose, namely the finite difference in time domain (FDTD), and the finite difference beam propagation method (2D and 3D FD-BPM), these in frequency domain. Initially, a TM (transverse magnetic) mode propagating through a planar magnetooptic/nonlinear/linear waveguide was investigated by way of a two-dimensional formalism (FDTD and FD-BPM). This mode polarization was chosen based on the orientation of the external magnetostatic field adopted, which favored the observation of non-reciprocal and nonlinear effects simultaneously. On the other hand, it is well known that FDTD formalisms are computationally intensives. Therefore, a great effort was dedicated to its frequency domain counterpart (FD-BPM), which was implemented in two and three dimensions. The later was further extended to a fully vectorial formalism, which is capable of simulating hybrid modes or even the energy transfer between orthogonal modes. This enabled us to investigate more complex geometries, such as an optical isolator based on magnetooptic rib waveguide. Additionally, complex phenomena, such as the dynamic of light condensates in bulk nonlinear Kerr media with saturation, also known as cubic-quintic nonlinear media, were investigated for the first time with a 3D vectorial formalism. Finally, numerical methods capable of handling any combination of materials with distinct optical properties (linear and/or nonlinear and/or magnetooptic) are an extraordinary tool for the scientific community for the design of new optical devices, as well as the investigation of new physical effects aimed for optical computing, that may result in fewer and more efficient components for optical communication systems.