Jaime García-Rupérez

Polytechnic University of Valencia | UPV · Valencia Nanophotonics Technology Center (NTC)

The combination of bimodal interferometric configurations with periodic photonic structures as subwavelength grating (SWG) waveguides and photonic crystals (PhCs) allows developing novel sensing configurations with increased sensitivity and reduced footprint.

Over the recent years, subwavelength grating (SWG) structures have increasingly attracted attention in the area of evanescent-field photonic sensors. In this Letter, for the first time to the best of our knowledge, we demonstrate experimentally the real-time refractive index (RI) sensing using the SWG bimodal interferometric structures. Two differe...

In this work, a porous silicon nanostructure has been fabricated by electrochemical means and used as a thermal sensor. The thermo-optic effect in the near infrared region has been experimentally studied based on spectroscopy measurements. Values of the thermo-optic coefficient between 3.2 and 7.9·10^{-5} K^{-1} have been obtained, depending on the...

Porous materials have become ideal candidates for the creation of optical sensors that are able to reach extremely high sensitivities, due to both the possibility to infiltrate the target substances on them and to their large surface-to-volume ratio. In this work, we present a new alternative for the creation of porous optical sensors based on the...

In a traditional planar photonic sensing structure only its external surface is typically used for sensing purposes. In order to increase its sensitivity, its surface/volume ratio takes relevance. In this respect, porous silicon (PSi) multilayer structures allow to increase this ratio as well as offering the possibility to infiltrate the target ana...

We present the development of a high index contrast nanoporous silicon platform to be used for the creation of ultrasensitive nanophotonic biosensing structures. In this work, we aim at mimicking the configuration of SOI (Silicon on Insulator) platform, where a thin high index top silicon layer sitting on a low index silicon oxide lower cladding is...

The objective of this work is to optimize the detection of antigens with integrated photonic sensing structures by using a protein A layer to promote bio-functionalization with specific antibody probes. Protein A allows the oriented attachment of antibody receptors over the sensor surface (see Fig. 1), since they bind to the protein layer through t...

In this work we present the development of a silicon-based integrated photonic biosensor where its bio-functionalization with specific antibody probes has been done using an intermediate protein A layer. This layer can be created over the sensor surface simply by physical immobilization, and it allows a proper orientation of the antibody probes for...

In this letter, we present experimental results of antibody detection using a biosensor based on photonic bandgap structures, which are interrogated using a power-based readout technique. This interrogation method allows a real-time monitoring of the association process between the antigen probes and the target antibodies, allowing the instantaneou...

Methodology for the functionalization of silicon-based materials employed for the development of photonic label-free nanobiosensors is reported. The studied functionalization based on organosilane chemistry allowed the direct attachment of biomolecules in a single step, maintaining their bioavailability. Using this immobilization approach in probe...

We present an analysis of the association kinetics of the BSA-antiBSA (antigen-antibody) complex by using a photonic bandgap biosensor. The readout of the biosensor is done using a real-time and low-cost power-based technique.

We discuss the development of label-free, real-time and low-cost biosensors based on planar photonic bandgap (PBG) structures. We propose a novel power-based readout technique where the PBG shift is indirectly tracked by simply exciting the photonic sensing structure with a filtered broadband source and measuring the output power with a power meter...

We present a sensing technique based on using photonic bandgap structures where only the output power is monitored, without the need of tunable sources or spectrum analyzers, thus providing a real-time and low-cost system.

A technique for the development of low-cost and high-sensitivity photonic biosensing devices is proposed and experimentally demonstrated. In this technique, a photonic bandgap structure is used as transducer, but its readout is performed by simply using a broadband source, an optical filter, and a power meter, without the need of obtaining the tran...

Narrow polarization-mixing resonances in planar photonic crystals are studied as candidate components for label-free refractive index sensors for detecting bacteria causing sepsis through the identification of DNA strands

We present experimental sensing results achieved using a novel technique based on the use of photonic bandgap structures where only the output power from a broadband source is monitored, providing a real-time and low-cost system.

We report an experimental demonstration of single-strand DNA (ssDNA) detection at room temperature using a photonic-crystal-waveguide-based optical sensor. The sensor surface was previously biofunctionalized with ssDNA probes to be used as specific target receptors. Our experiments showed that it is possible to detect these hybridization events usi...

We report experimental results of label-free anti-bovine serum albumin (anti-BSA) antibody detection using a SOI planar photonic crystal waveguide previously bio-functionalized with complementary BSA antigen probes. Sharp fringes appearing in the slow-light regime near the edge of the guided band are used to perform the sensing. We have modeled the...

We report an experimental demonstration of single-strand DNA detection at room temperature using a photonic crystal waveguide based optical sensor. A detection limit of 19.8nM is obtained.

We report an experimental demonstration of DNA detection using a photonic crystal waveguide based optical sensor. A detection limit of 110nM is achieved for hybridized biotinylated DNA oligomers on the streptavidin-coated Silicon biosensor.

We demonstrate experimentally all-optical switching on a silicon chip at telecom wavelengths. The switching device comprises a compact ring resonator formed by horizontal silicon slot waveguides filled with highly nonlinear silicon nanocrystals in silica. When pumping at power levels about 100 mW using 10 ps pulses, more than 50% modulation depth i...

We study cross-slot waveguides for polarization diversity schemes that simultaneously offer strong confinement in the slot region for both TE and TM polarizations. A symmetric configuration is initially presented to demonstrate that the same strong confinement and propagation constants can be obtained for both polarizations and slot thicknesses dow...

A novel OSNR monitoring technique based on use of optical pulse correlation is demonstrated experimentally. By measuring statistics extracted from the autocorrelation peak, the OSNR is estimated with an error of less than 0.5 dB.

A comparison between several 1D periodic structures designed to enhance non-linear effects for high-speed all-optical applications is presented. These structures allow for a small group velocity of the propagating waves, so the light-matter interaction is increased, making the non-linear process to be more efficient. In addition, the propagating wa...

Slow-wave structures do not only provide benefits. One of their most important problems is the increase of roughness losses when group velocity decreases. This dependence has been theoretically studied for some 1D periodic structures.

We present a detailed analysis of the influence of the finite length of a photonic crystal (PhC) waveguide on its final response to pulses propagation. The analyzed PhC waveguide is accessed by conventional dielectric waveguides and the lack of a perfect coupling between them produces reflections at the interfaces, leading to the appearance of seve...

A planar photonic crystal that allows inherently gap-guided single-mode waveguides is proposed and discussed. This novel structure consists of a two-dimensional lattice of silicon rods embedded on a thin silica slab sandwiched between two silica claddings whose refractive indices are slightly lower than the index of the silica core. The physical pa...

We propose a structure that allows the splitting of electromagnetic waves with a phase shift of 180° between output signals based on photonic crystals. The structure consists of two parallel coupled-cavity waveguides placed in proximity. The performance of the splitting structure is theoretically discussed, evaluated by means of finite-difference t...

We overview our recent developments in nanophotonic biosensor arrays for the detection of whole bacteria and PCR products. The work is part of the EU InTopSens project, with the aim to demonstrate the feasibility of a rapid diagnostic test for sepsis. This requires detecting the presence and identification of bacteria species from whole blood and t...

El desarrollo de las tecnologías ópticas de transmisión permite disponer hoy en día de grandes anchos de banda y elevadas velocidades de transmisión, lo que permite proporcionar servicios de una calidad cada vez mayor a un mayor número de usuarios. Para dar un paso más en el campo de las comunicaciones ópticas es necesario el desarrollo de disposit...