O interesse na pesquisa de Lasers randômicos, meios dispersivos com alto ganho, tem crescido nos últimos anos em virtude das novas possibilidades advindas ao se trabalhar com estes sistemas, como emissões em bandas com baixo ganho, bicromaticidade, localização da luz em meios difusos e sistemas ópticos mais compactos. Nesse trabalho serão discutidos temas como espalhamento da luz por partículas, intensidade de retroespalhamento, ganho em meios desordenados e as transições energéticas do neodímio, correlacionando as emissões características obtidas nos experimentos com a teoria. Quanto aos resultados será apresentado a primeira observação de laser randômico com nanopó de Nd:YVO4 através de análise do comportamento da emissão espectral e temporal oriunda da transição 4F3/24I11/2 (1064 nm). Os resultados apresentam outra forma de analisar a cinética temporal da emissão de laser randômico, permitindo uma separação da fração de emissão estimulada e espontânea e comparação desse resultado com o estreitamento sutil da largura de linha, típico de lasers randômicos. As conversões ascendentes e saturação de ETU (conversão ascendente por transferência de energia) serão analisadas na mesma amostra, sendo todos os ajustes provenientes da literatura e de fundamental interesse, principalmente por se tratarem de um mecanismo de perda em lasers operando na região do infravermelho. Por fim, a emissão característica será avaliada pela técnica CBS (retroespalhamento coerente) para determinação da coerência do laser emitido e localização da luz neste meio difuso, com os resultados comparados aos da simulação. / In the past few years, the interest in random lasers, which refer to lasing in disordered media where strong multiple scattering plays a constructive role instead of being only a loss factor, have received considerable attention due to its unique properties and its potential applications, such as emission at new, extremely low gain lines, simultaneous emission of several very different wavelengths at the same time, strong light localization and miniaturization. Single and multiple particle light scattering, backscattering intensity, light diffusion with gain and the energy level diagram of Neodymium will be presented in this current work, alongside with a parallel from the typical emission lines obtained experimentally with theory. The demonstration of random laser action in Nd:YVO4 nanopowder, by analyzing the spectral and temporal behavior from the 4F3/24I11/2 (1064 nm) transition is presented. A method that analyzes the decay kinetics after long-pulse excitation is used to determine the laser characteristics, allowing measuring the fractional contribution of spontaneous and stimulated emission in the samples backscattering cone, with is in agreement to the smoothing linewidth narrowing as a function of pump power typical from random lasers. Also the visible emission along a method to determine quantitatively the ETU (energy-transfer upconversion) rate is presented, which is particularly interesting, as is a mechanism that introduces a loss channel for devices emitting in the infrared region. At last, the coherent laser emission and light localization will be evaluated by using the CBS (coherent backscattering) technique in this diffusive media, in which the results are compared with simulation.

Les nanoparticules d'YVO4:Eu peuvent être utilisées individuellement, en tant que sondes biologiques, ou assemblées, en couches minces par exemple. Pour ces deux applications, la nanostructure de ces objets impacte fortement leurs propriétés. Sa maîtrise serait donc un atout de choix. Dans une première partie, la structuration de ces nanomatériaux au cours de leur synthèse a été suivie par diffusion des rayons X (SAXS/WAXS) couplée à une mesure de fluorescence. La première étape du mécanisme de formation consiste en la précipitation d'un hydroxyde mixte amorphe, filandreux et peu luminescent. Puis, la phase YVO4:Eu cristallise sous forme de grains de 4 nm qui apparaissent directement à leur taille finale ; on parle de nucléation pop-corn. Finalement, ces grains se réorganisent en nanoparticules hiérarchiques de 40 nm. Au cours de cette étude, il est apparu que la structure du précipité initial jouait un rôle important sur la nanostructure des particules. Dans la seconde partie, nous nous sommes focalisés sur les applications de ces particules en couches minces luminescentes et transparentes par pulvérisation. Rapidement, nous avons été confrontés à l'effet tache de café. Ce dernier est coupable de causer des dépôts anisotropes et, par conséquent, des couches diffusantes. En le supprimant progressivement, nous avons pu contrôler la forme des dépôts de gouttes uniques et ainsi faire varier la transparence des films. Ces résultats ont été appliqués à différentes particules luminescentes afin de produire les couches les plus luminescentes et les plus transparentes possibles. Finalement, l'étude a été étendue aux couches à upconversion.

In this work, we have investigated the thermal properties (diffusivity (D), conductivity (K), temperature coefficient of the optical path length change (ds/dT), etc) and loss processes owing to the ion-ion interactions, in Nd3+ doped laser materials, specifically YAG ceramic and CGGG crystal. Since the fluorescence quantum efficiency, , is directly related to these mechanisms that lead to luminescence quenching, the studies were carried out mainly observing the effects of these processes on . To this goal we used mainly the thermal lens technique and conventional spectroscopy. In Nd:YAG ceramic, we have investigated the losses due to down-conversion or, as they are well known, concentration quenching that are basically cross relaxation (CR) and energy migration (EM). From these results, it was concluded that the main source of luminescence quenching is CR and that the small ds/dT value together with the high optimum concentration put this material as candidate for several applications. In Nd:CGGG crystal, we have studied the loss processes owing to upconversion or, as is better known, upconversion Auger (UA) or energy transfer upconversion, which are important in laser systems of high. / Fundação de Amparo a Pesquisa do Estado de Alagoas / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Neste trabalho investigamos as propriedades térmicas (difusividade (D), condutividade (K), variação do caminho óptico com a temperatura (ds/dT), etc) e processos de perdas devido a interações entre íons, em materiais lasers dopados com Nd3+, especificamente cerâmica de YAG e cristal CGGG. Desde que a eficiência quântica de fluorescência, , está diretamente relacionada com esses mecanismos que levam a supressão da luminescência, os estudos foram realizados principalmente observando os efeitos desses agentes sobre . Para esse propósito, usamos principalmente a técnica de lente térmica e espectroscopia convencional. Na cerâmica de Nd:YAG investigamos as perdas por down-conversion ou, como é melhor conhecidas, quenching de concentração que são basicamente relaxação cruzada (RC) e migração de energia (ME). Nesses resultados concluímos que a principal fonte de supressão da luminescência é RC e que o valor de ds/dT baixo juntamente com a concentração ótima alta apresentam esse material com boas perspectivas de aplicações. No cristal Nd:CGGG estudamos os processos de perdas por upconversion ou, como é melhor conhecido, conversão ascendente Auger (CAA) ou conversão ascendente por transferência de energia, os quais são importantes em sistemas lasers de alta potência e/ou altas concentrações de íons dopantes. Com a presença dos processos de CAA é adicionado mais um canal de decaimento não radiativo. E como resultado foi observado uma diminuição de η e consequentemente um aumento da carga térmica (φ). O conhecimento dos processos investigados nesta dissertação é de importância fundamental para a engenharia e caracterização de matérias lasers.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2015-10-20T11:38:47Z No. of bitstreams: 2 Dissertação - Ariadne Canedo Eduardo - 2015.pdf: 1635500 bytes, checksum: 5c68f75920a8fc69b6de996110938818 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2015-10-20T11:40:09Z (GMT) No. of bitstreams: 2 Dissertação - Ariadne Canedo Eduardo - 2015.pdf: 1635500 bytes, checksum: 5c68f75920a8fc69b6de996110938818 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-10-20T11:40:09Z (GMT). No. of bitstreams: 2 Dissertação - Ariadne Canedo Eduardo - 2015.pdf: 1635500 bytes, checksum: 5c68f75920a8fc69b6de996110938818 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-02-26 / In recent years, research in the nanocomposites area of core-shell type increased significantly. The core-shell type nanoparticles with photoluminescence properties (PL) attract much attention from the scientific community. Are also of great interest nanoparticles that exhibit the upconversion energy, i.e. they absorbing low energy photons and emission high-energy photons. The present work has as objective nanocomposites synthesis of core-shell type, with CaTiO3 matrix (CT) and doped with rare earth ions Er3+ and Yb3+ in a variety composition and variations, to analysis the photoluminescent properties. The nanoparticles of the core and shell were obtained by the Method of Polymeric Precursors. The samples were characterized by X-ray diffraction (XRD) for structural characterization, and it was found that All samples presented the perovskite structure of the orthorhombic type. The characterization by Transmission Electron Microscopy (TEM) failed to demonstrate the formation of core-shell, requiring analysis by Energy Dispersive X-ray (EDX), which showed the presence of rare earth Er3+ and Yb3+ in the different layers. The UV-Vis gap allowed the calculation of the shell and core samples. The PL emission results were used to relate the thickness of the shell and the intensity of the emission. On the other hand, to study the upconversion energy, core materials showed a higher intensity than in the core-shell; the best intensity in the core-shell was found with doping the core with Yb3+ and Yb3+ with shell and Er3+ suggesting the transfer of energy between the layers. / Nos últimos anos, pesquisas na área de nanocompósitos do tipo core-shell cresceram significativamente. Atualmente nanopartículas do tipo core-shell com propriedades fotoluminescente (FL) atraem muita atenção da comunidade científica. Também são de grande interesse nanopartículas que apresentam a conversão ascendente de energia, ou seja, absorção de fótons de baixa energia e emissão de fótons de alta energia. O presente trabalho teve como objetivo a síntese de nanocompósitos do tipo core-shell, com a matriz CaTiO3 (CT) e dopagem com os íons terras raras Er3+ e Yb3+ nas mais variadas composições, para análise da propriedade fotoluminescente. As nanopartículas do core e do shell foram obtidas pelo Métodos dos Precursores Poliméricos. As amostras foram caracterizadas por Difração de Raios X (DRX) para caracterização estrutural, e foi constatada que todas as amostras apresentaram a estrutura perovsquita do tipo ortorrômbica. A caracterização por Microscopia Eletrônica de Transmissão (MET) não foi conclusiva quanto a formação do core-shell, sendo necessária a análise por Energia Dispersiva de Raios X (EDX), na qual verificou-se a presença das terras raras Er3+ e Yb3+ nas diferentes camadas. A espectroscopia de UV-Vis permitiu o cálculo do gap para as amostras core e shell. Os resultados de emissão FL foram utilizados para relacionar a espessura do shell e a intensidade da emissão. Por outro lado, ao estudar a conversão ascendente de energia, os materiais core apresentaram maior intensidade do que no core-shell; a melhor intensidade no core-shell foi verificada com a dopagem do core com Yb3+ e do shell com Yb3+ e Er3+, sugerindo a transferência de energia entre as camadas.

O interesse na pesquisa de Lasers randômicos, meios dispersivos com alto ganho, tem crescido nos últimos anos em virtude das novas possibilidades advindas ao se trabalhar com estes sistemas, como emissões em bandas com baixo ganho, bicromaticidade, localização da luz em meios difusos e sistemas ópticos mais compactos. Nesse trabalho serão discutidos temas como espalhamento da luz por partículas, intensidade de retroespalhamento, ganho em meios desordenados e as transições energéticas do neodímio, correlacionando as emissões características obtidas nos experimentos com a teoria. Quanto aos resultados será apresentado a primeira observação de laser randômico com nanopó de Nd:YVO4 através de análise do comportamento da emissão espectral e temporal oriunda da transição 4F3/24I11/2 (1064 nm). Os resultados apresentam outra forma de analisar a cinética temporal da emissão de laser randômico, permitindo uma separação da fração de emissão estimulada e espontânea e comparação desse resultado com o estreitamento sutil da largura de linha, típico de lasers randômicos. As conversões ascendentes e saturação de ETU (conversão ascendente por transferência de energia) serão analisadas na mesma amostra, sendo todos os ajustes provenientes da literatura e de fundamental interesse, principalmente por se tratarem de um mecanismo de perda em lasers operando na região do infravermelho. Por fim, a emissão característica será avaliada pela técnica CBS (retroespalhamento coerente) para determinação da coerência do laser emitido e localização da luz neste meio difuso, com os resultados comparados aos da simulação. / In the past few years, the interest in random lasers, which refer to lasing in disordered media where strong multiple scattering plays a constructive role instead of being only a loss factor, have received considerable attention due to its unique properties and its potential applications, such as emission at new, extremely low gain lines, simultaneous emission of several very different wavelengths at the same time, strong light localization and miniaturization. Single and multiple particle light scattering, backscattering intensity, light diffusion with gain and the energy level diagram of Neodymium will be presented in this current work, alongside with a parallel from the typical emission lines obtained experimentally with theory. The demonstration of random laser action in Nd:YVO4 nanopowder, by analyzing the spectral and temporal behavior from the 4F3/24I11/2 (1064 nm) transition is presented. A method that analyzes the decay kinetics after long-pulse excitation is used to determine the laser characteristics, allowing measuring the fractional contribution of spontaneous and stimulated emission in the samples backscattering cone, with is in agreement to the smoothing linewidth narrowing as a function of pump power typical from random lasers. Also the visible emission along a method to determine quantitatively the ETU (energy-transfer upconversion) rate is presented, which is particularly interesting, as is a mechanism that introduces a loss channel for devices emitting in the infrared region. At last, the coherent laser emission and light localization will be evaluated by using the CBS (coherent backscattering) technique in this diffusive media, in which the results are compared with simulation.

The Quantum Cascade Laser (QCL)-based terahertz-over-fibre (ToF) concept combines the strength of QCLs as ultra-wide bandwidth, high speed data sources, with the mature optical fibre technology. In this thesis, for the first time, by fusing multiple technologies, digitally selected, electronically-switchable ToF concept is experimentally demonstrated. Furthermore, the digital mode selection principle and electronic tuning mechanism provided by novel aperiodic distributed feedback (ADFB) multi-band filters are presented. For the development of electronically tunable ADFB lasers, a range of bound-to-continuum and chirped superlattice terahertz (THz) QCLs are measured across the frequency range 2.9 – 4.5 THz. The availability of these active materials allowed rapid assessments of the optimum design parameters for subsequent measurements. First, a range of photonic lattice-engineered lasers operating at 4.4 THz are characterized and key design parameters identified. Following this initial development, full electrical and spectral characterization of ADFB lasers operating at 2.9 THz are presented. The novelty of this work lies in the first-ever successful demonstration of discretely tunable QCLs, operating at six distinct THz frequencies. The ADFB technology was experimentally applied using various device geometries and gain dynamics. Toward this aim, results are presented for a Y coupled QCL architecture, showing that complex on-chip signal manipulation can be extended into the THz regime. In addition, it is demonstrated that ADFB technology provides broadband multi-channel optical filtering for the entire gain bandwidth. It is shown that discrete, purely electronic, tuning of simultaneous dual colour output can be achieved. Multi band optical filter functions derived from ADFB gratings possess highly nonlinear dispersion across the filter bandwidth and are found to modify the gain-induced, driving current-dependent continuous mode tuning. This thesis, therefore, presents a systematic experimental analysis of the dispersion engineered continuous fine-tuning in THz QCLs. In the final two chapters, the thesis presents, for the first time, transmission of tunable THz signals over standard single-mode optical fibre by up converting 2.9 THz QCL radiation via intra-cavity nonlinear mixing with an optical fibre-injected near-infrared (NIR) carrier in the 1.3 µm band. Discrete and continuous tuning technologies, as developed in chapters 3 – 5, are now successfully transferred to THz sidebands on the NIR carrier, extracted via a butt coupled single mode fibre and recorded using an optical spectrum analyzer. The major novel outcome of this thesis is the first demonstration of electronically tunable phase-matched points in a THz plasmon waveguide. The key breakthrough is the experimental confirmation of the photonic band-gap engineering of group velocity of THz signals – as both ‘fast’ and ‘slow’ switchable side bands are observed. Such novel nonlinear up-conversion of spectrally flexible THz signals may open up new possibilities for ultrafast THz telecom frameworks.

Ce travail de thèse porte sur l’étudephoto-physique de chromophores donneur-π-accepteur utilisés dans les cellules solaires àcolorant. Après photo-excitation, ces moléculessubissent des processus de transfert de chargeintramoléculaire (ICT), de solvatation etd’injection de charges qui se déroulent dans ledomaine temporel de la picoseconde. Or touterelaxation énergétique de l’état excité diminue lacinétique de l’injection de charges.Des mesures de spectroscopie stationnaire et defluorescence résolue en temps (de la femto- à lananoseconde) ont permis de résoudre ladynamique de relaxation de ces colorants ensolution, sur films mésoporeux et en cellulescomplètes.Les dynamiques de relaxation spectrale etd’inhibition de l’intensité de fluorescence del’état excité ont pu être caractériséesindépendamment et mettent en évidence unchangement d’état électronique à l’état excité.Les trois colorants étudiés évoluent vers un étatà transfert de charge (état CT). Un tel étatinteragit fortement avec son environnement.Afin d’étudier l’injection de charge dans lesoxydes mésoporeux semi-conducteurs, unmontage expérimental de fluorescence résolue entemps destiné à l’étude de systèmes opaques etdiffusifs a été réalisé et est décrit dans cette thèse.Ce montage possède une résolution temporelled’environ 300 fs.Les résultats mettent en évidence la présenced’une compétition entre l’injection de charges etla relaxation de l’état excité dans les cellulescomplètes. / This thesis deals with thephotophysical study of donor-π-acceptorchromophores used in dye sensitized solar cells.After photo-excitation, these molecules undergointramolecular charge transfer (ICT), solvationand charge injection processes that take place inthe picosecond time domain. However, anyenergetic relaxation of the excited statedecreases the injection kinetics.Steady-state spectroscopy and time-resolvedfluorescence measurements (from the femto- tothe nanosecond) were used to solve therelaxation dynamics of these dyes in solution, onmesoporous films and in complete cells.The spectral relaxation and fluorescencequenching dynamics of the excited state couldbe characterized independently and highlight anelectronic relaxation at the excited state. Thethree dyes studied evolve towards a chargetransfer state (CT state). Such a state is in stronginteraction with its environment.To study charge injection in semiconductormesoporous oxides, a time-resolvedfluorescence set-up for the study of opaque anddiffusive systems has been implemented and isdescribed in this thesis. It provides a timeresolution of about 300 fs.The results demonstrate the existence of acompetition between the injection of chargesand the relaxation of the excited state in thecomplete cells

This diploma thesis deals with evaluation of toxicity and bioaccumulation of photon-upconversion nanoparticles (UCNPs) in model plant maize (Zea mays). Lanthanide-doped UCNPs with different composition and size were tested in three different concentrations in this work. The exposure took place for 168 hours. Toxicity was assessed based on four macroscopic toxicological endpoints (mortality, the length of belowground part of the plants, the length of aboveground part of the plants and whole plants length). Spatial distribution of elements yttrium, ytterbium, erbium and gadolinium in model plants was determined using laser induced breakdown spectroscopy with spatial resolution of 100 m and 26 m. Distribution of UCNPs in plants was further studied with photon-upconversion microscanning with spatial resolution of 40 m. Stability of UCNPs during and after the plant exposure was also discussed in this thesis.

Les applications de détection infrarouge active sont nombreuses dans le domaine de la défense et la sécurité. Cependant ces systèmes sont actuellement peu utilisés en pratique à cause de leur portée limitée. Un moyen d’augmenter cette portée est d’améliorer la sensibilité des détecteurs infrarouges qui possèdent des bruits bien plus élevés que leurs équivalents dans le visible. L’idée principale de cette thèse est d’utiliser l’optique non linéaire pour effectuer une conversion de fréquence du signal infrarouge à détecter vers de plus basses longueurs d’ondes et ainsi bénéficier des performances des détecteurs fonctionnants à ces longueurs d’ondes. Les développements récents en cristaux donnent un intérêt nouveau à ces techniques pour certains cas applicatifs identifiés au cours de cette thèse. L’étude détaillée de la conversion multimode à la fois temporelle et spatiale, a permis de proposer une méthode simple et originale pour dépasser l’état de l’art en terme de nombre d’éléments résolus convertis. Pour quantifier précisément les avantages de ces conversions, une étude théorique et numérique de la conversion multimode a été menée et deux séries d’expériences ont été conduites. La première concerne la détection ponctuelle de signaux moyen-infrarouge pour des applications de spectroscopie par conversion dans un cristal d’OP-GaAs. La deuxième concerne la détection de cibles par imagerie active dans le proche infrarouge par conversion dans un cristal de PPLN vers une caméra CMOS. Les performances en sensibilité obtenues sont dans les deux expériences meilleures d’un ordre de grandeur que les détections directes avec les détecteurs habituellement utilisés. / There is a wide range of applications in active infrared detection technologies in defense and security. However, the limited range available by these systems limits their developments. Increasing sensors sensitivity is a key milestone to improve this range. Indeed, noise in infrared detectors is much higher than for visible detectors due to some physical and technological issues. The key idea of this manuscript is to use nonlinear optical technologies to convert the infrared signal to detect into the visible spectrum and use all the benefits of silicon based sensors. Recent advances in optical crystals and in pump laser regimes bring renewed interest to upconversion detection for some specific application cases identified in this thesis. A novel and easy method to improve the number of converted modes has been proposed after a careful study of multimode conversion both temporally and spatially. In order to give figures on detection improvement using upconversion, we conducted a theoretical and numerical study of the multimode conversion as well as two sets of experiments. The first one, using conversion in an OP-GaAs crystal and a monodetector addresses mid-infrared spectroscopy applications. The second one addresses active imaging applications for target recognition and identification in the near-infrared. By using a PPLN crystal, the near-infrared image is detected on a low noise CMOS camera. A key milestone of this work is the sensitivity improvement of such a detection. Sensitivities obtained in each experiment are one order of magnitude better than with direct detection using common infrared sensors.

Optische Sonden für die Bildgebung auf Grundlage des pH-Wertes sind für die Wissenschaft von großem Interesse, da es sich beim pH-Wert um eine entscheidende Kenngröße für viele Prozesse in der Biotechnologie, Biologie, medizinische Diagnostik, biomedizinische Forschung und Materialkorrosion handelt. Optische pH-Sensoren, deren Funktionsprinzip auf dem photophysikalischen Prozess Fluoreszenz basieren, sind dabei von besonderem Interesse, da die Fluoreszenz eine sehr hohe Empfindlichkeit, welche sogar die Auflösung einzelner Moleküle ermöglicht, bietet. Dies ermöglicht den Einsatz von molekularen über nanoskaligen Sensorformaten bis hin zur Anwendung in planaren Optoden oder faseroptischen Sensoren, und gilt, neben der nicht-invasiven, zerstörungsfreien und kontaktlosen Natur optischer Fluoreszenzmessungen, als anwendungsfreundliche Eigenschaft dieser optischen Sensoren. Der Informationsgehalt fluoreszenzintensität-basierender Sensoren ist normalerweise unspezifisch auf die An- oder Abwesenheit des Fluorophors und des Analyten beschränkt. Weiterhin kann er durch Schwankungen der Intensität des Anregungslichts und Änderungen der Fluorophorkonzentration, z.B. durch Photodegradation, beeinflusst werden. Daher werden Fluoreszenzsensoren oftmals in referenzierten Systemen verwendet. Diese Systeme ermöglichen, durch die Einführung einer analyt-inerten Referenz, ein duales, ratiometrisches Auslesen der Fluoreszenzintensitäten von zwei spektral unterscheidbaren Komponenten. In dieser Arbeit wird das konzeptionelle Design einer modular variierbaren, auf mehreren Komponenten basierenden Plattform für die ratiometrische optische Analytmessung vorgestellt. Dazu wurden fluoreszente, leicht zugängliche und analyt-sensitive Boron-Dipyrromethene (BODIPYs) mit durch nahes Infrarot (NIR) anregbare, mehrfarbig emittierende Aufkonvertierungs-Nanopartikel (UCNPs) kombiniert. Das Sensorprizip beruht dabei auf einem inneren Filter-Effekt der spektral abgestimmten Komponenten. / Optical probes for monitoring, imaging, and sensing of pH are of great interest for the scientific community as pH is a crucial marker for many processes in biotechnology, biology, medical diagnostics, biomedical research, and material corrosion. Thereby, optical pH sensors based on fluorescence have attracted interest in particular as fluorescence offers a high sensitivity down to the single molecule level, can be read out with relatively simple and readily miniaturized instrumentation, and allows online in situ measurements. Also the versatility ranging from molecular and nanosensor formats to planar optodes and fiber-optic sensors, and the non-invasive, non-destructive, and contactless nature of the measurement are application-friendly features. The information content, which is offered by a fluorescence intensity-based sensor, is usually unspecific and limited on the presence or the absence of the chromophore or analyte and can additionally be hampered by fluctuation of the excitation light intensity and changes in fluorophore concentration, e.g., due to photobleaching. Therefore, many fluorescence sensors are utilized in referenced systems, which enable twowavelength ratiometric measurements of the fluorescence intensity by the introduction of an analyte-inert reference with a spectrally distinguishable emission. This work presents the rational design of a versatile, modular, multi-component-based platform for ratiometric optical analyte sensing that can be simply adapted to different formats and measurement geometries. Therefore, readily available analyte-responsive fluorescent boron-dipyrromethene (BODIPY) dyes and near infrared (NIR)-excitable multicolouremissive upconversion nanoparticles (UCNPs) were combined utilizing an inner filter-based strategy with spectrally matched moieties.