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A hybrid titanium dioxide/silicon rich nitride ring resonator with the unique feature of being simultaneously athermal and polarization-insensitive is reported for the first time to our knowledge. Although its potential application domain is extremely wide, the designed integrated microphotonic cavity, having a racetrack shape, is intended for notch filtering in a microwave photonic passband filter. A careful selection of the CMOS-compatible material system and an innovative design approach have allowed a very low dependence of the filtering shape on the input beam polarization and, simultaneously, a thermal drift of the resonance wavelength 4, 4 nm, and 30.7 dB, respectively.

The paper reports on the design of a silicon photonic TM-pass polarizer intended for photonic integrated circuits with a high component density. The device, whose design is compliant with the technological constraints imposed by a typical state-of-the-art silicon photonic process, exhibits a record IL of 0.05 dB @ 1.55 μm, a high ER of 38 dB @ 1.55 µm, and a broadband operation with IL 30 dB over 200 nm covering the S, C, and L bands.

We present the design of an asymmetric slot waveguide to facilitate selective TM mode coupling from a strip waveguide as basic building block of a TM-pass polarizer with record IL of 0.05 dB @ 1.55 μm.

A multi-analyte biosensing platform for the selective label-free detection of protein biomarkers has been designed through a three-dimensional model based on the finite element method. The sensing element of the platform is a planar plasmonic nanocavity, consisting of a one-dimensional periodic structure (Bragg grating) in gold, with a defect, placed on the buried oxide of a silicon-on-insulator substrate. The footprint of this sensing element, which has a good chemical stability, is only 1.57 μm2. The sensor has a detection limit of 128 pg/mm2 and a surface sensitivity of 1.8 nm/nm.

Monitoring of bacteria metabolism/viability at single level during the antibiotics action is a crucial functionality for systems supporting the development of new drugs able to kill bacteria resistant to all or nearly all antibiotics currently available. In this paper, we report on an electro-photonic chip-scale microsystem including an array of photonic nanocavities each able to trap a single bacterium. By monitoring the spectral response of the nanophotonic cavities and the electrical impedance across the trapping sites, a detailed knowledge of the metabolic state of trapped bacteria can be obtained. By three-dimensional simulations based on the finite element method, we predict a high electrical detection resolution of the microsystem, with a current variation of a factor 12 between dead and live bacteria.

A novel ultra-compact photonic tuneable notch filter with large bandwidth, high extinction ratio, fast response, and flat stopband is modeled and designed. It consists of a silicon-based ring resonator with one-dimensional photonic crystal superimposed onto a ring portion. Engineering the defects into the photonic crystal section allows to achieve the equalization of the bottom band of the filter response. Large bandwidth ( B = 10.43 GHz) and high extinction ratio (ER = 41 dB) have been attained with a frequency response of the first-order Butterworth filter type. Continuous and wide range tunability of the central frequency (15 GHz) has been obtained by using the carrier injection technique, together with fast reconfigurability (a1 ns) and power consumption of 47 mW. The device footprint is as very small as about 150 μm2. This performance makes the proposed device suitable for several filtering applications, such as wireless networks (5G) and telecommunication reconfigurable payloads in Telecom and Space scenario, respectively.

Beam steering in phased array antennas for some demanding terrestrial and space applications needs ultra-wide band true-time tunable delay lines preventing the beam squint phenomenon. Recent advances in the field of integrated microphotonics have allowed the demonstration of compact chip-scale delay lines with fast and low-power tuning mechanisms. For the tuning, several approaches have been theoretically and experimentally investigated and among them, very promising results have been obtained by using graphene in resonant delay lines based on the slow light effect. In this paper, after a brief review on resonant microphotonic tunable delay lines, some selected recent results on an ultra-compact graphene-based optical delay line including a silicon Bragg grating, are proposed.

The design of a new graphene-based continuously tunable optical delay line formed by two vertically stacked microring resonators coupled to a straight waveguide is proposed. High values of delay time (τg = 360 ps) and a wide tuning range (Δτg = 230 ps) have been calculated, due to the graphene sandwiched between the stacked ring resonators, which also provides an electrooptical tuning of the delay with low energy consumption (Eswitch = 3.4 pJ) and fast switching time (tswitch -1 ps/μm2 has been calculated, which corresponds to an enhancement of about a factor 4 compared with the state-of-the-art of the integrated optical delay lines, also providing a switching time several times faster. Such performance, together with a small device footprint (3 μm2), gives a significant contribution to the state-of-the-art of optical delay lines, confirming the suitability of the graphene-based resonant cavity as a high-efficient optical delay line for applications in which fast tuning and wide range of tunability are required, e.g., phased array antennas.

Microwave photonic filters with a performance not achievable by the conventional RF technology, are currently a hot topic in the field of microwave photonics. In this paper, after a brief review of the state-of-the-art of microwave integrated photonic filters and their application in space engineering, the design of a new band-pass filter configuration based on a ring resonator with a photonic crystal included in the resonant path is proposed. The achieved performance parameters are a full-width-at-half-maximum of 10 pm, a Q-factor of 1.5×105, with an extinction ratio equal to 40 dB, and a maximum ripple less than 0.5 dB, within the wavelength range λ 0 ± FWHM/4 (with λ 0 = 1550 nm). The ring is in silicon technology and it can be integrated with other optoelectronic/photonic components of the filter through a hybrid approach.

A novel photonic/plasmonic cavity based on a 1-D photonic crystal cavity vertically coupled to a plasmonic gold structure is reported. The design has been optimized to achieve an ultra-high Q/V ratio, therefore improving the light–matter interaction and making the device suitable for optical trapping applications. Accurate 3-D finite element method (FEM) simulations have been carried out to evaluate the device behavior and performance. The device shows ${\rm Q} = 2.8 \times 10^{3}$ and ${\rm V} = 4 \times 10^{-4} (\lambda/{\rm n})^{3}$ , which correspond to a ${\rm Q}/{\rm V} = 7 \times 10^{6} (\lambda/{\rm n})^{-3}$ with a resonance transmission around 50% at $\lambda_{\rm R} = 1589.62\ \hbox{nm}$ . A strong gradient of the optical energy has been observed in the metal structure at the resonance, inducing a strong optical force and allowing a single particle trapping with a diameter less than 100 nm. The device turns out very useful for novel biomedical applications, such as proteomics and oncology.

Whispering Gallery Mode photonic resonators are emerging as key building blocks in many application fields especially because their resonant frequency is very sensitive to the variation of any physical or geometrical parameter. The basic properties and the applications of these resonators are discussed in this paper, with a specific attention to three very important application fields, i.e. Space, health-care, and environment monitoring.

In the last few years, the interest towards chip-scale microphotonic resonant label-free biosensor is quickly growing. In this context, novel low-cost platforms able to simultaneously detect, with high resolution, several target molecules in an ultra-small volume of biologic fluid are strongly demanded. In this paper, the recent advances in the field of resonant microphotonic platforms for label-free biosensing are critically reviewed, with a special emphasis on the devices exhibiting an ultra-high sensitivity due to a strong light-matter interaction. A new multi-analyte biosensing platform in silicon nitride technology is reported. The platform is based on a properly designed configuration of planar ring resonator and exhibits a record limit-of-detection of 0.06 pg/mm2. The applications of the platform in the field of medical diagnostics and environmental monitoring are discussed.

In this paper, a very accurate model of optical modulators in silicon-on-insulator technology is developed and validated using experimental results reported in literature. Using an optimized nanometer MOS structure, a significant bandwidth increase (around 45%), length decrease (around four times), and power consumption reduction (three times) with respect to the state-of-the-art have been obtained.

Integrated optical nanotweezers offer a novel paradigm for optical trapping, as their ability to confine light at the nanoscale leads to extremely high gradient forces. To date, nanotweezers have been realized either as photonic crystal or as plasmonic nanocavities. Here, we propose a nanotweezer device based on a hybrid photonic/plasmonic cavity with the goal of achieving a very high quality factor-to-mode volume (Q/V) ratio. The structure includes a 1D photonic crystal dielectric cavity vertically coupled to a bowtie nanoantenna. A very high Q/V ~ 107 (λ/n)−3 with a resonance transmission T = 29 % at λ R = 1381.1 nm has been calculated by 3D finite element method, affording strong light–matter interaction and making the hybrid cavity suitable for optical trapping. A maximum optical force F = −4.4 pN, high values of stability S = 30 and optical stiffness k = 90 pN/nm W have been obtained with an input power P in = 1 mW, for a polystyrene nanoparticle with a diameter of 40 nm. This performance confirms the high efficiency of the optical nanotweezer and its potential for trapping living matter at the nanoscale, such as viruses, proteins and small bacteria.

A hybrid device based on a 1D PhC dielectric cavity vertically coupled to a plasmonic slot is proposed for use in biosensing applications. Under efficient coupling conditions between the Bloch mode in the 1D PhC dielectric cavity and the surface plasmon polaritons mode in the metal slot, an ultra-high Q / V ratio (~10 7 ( λ / n ) −3 ) has been achieved with a remarkable resonance transmission T (=47%), due to high spectral and spatial confinement in the cavity. The rigorous design process of the cavity, including the influence of geometrical and physical parameters on its performance, has been carried out using the 3D Finite Element Method. A strong light-matter interaction was observed, making the photonic-plasmonic cavity suitable for biosensing and, in particular, for optical trapping of living matter at nanoscale, such as proteins and DNA sections, as required in several biomedical applications.

The design of an integrated graphene-based fine-tunable optical delay line on silicon nitride for optical beamforming in phased-array antennas is reported. A high value of the optical delay time (τg=920 ps) together with a compact footprint (4.15 mm2) and optical loss

A high Q/V mid-infrared 1D photonic crystal cavity in chalcogenide glass AMTIR-1 (Ge33As12Se55) resonating at λR=5.26 μm has been proposed as a key element of a sensor able to evaluate the nitric oxide (NO) concentration in the exhaled breath, namely fraction exhaled NO. The cavity design has been carried out through 3D finite-element method simulations. A Q-factor of 1.1×104 and a mode volume V=0.8 (λ/n)3, corresponding to a Q/V ratio of 1.4×104(λ/n)−3, have been obtained with a resonance transmission coefficient T=15%. A sensitivity of 10 ppb has been calculated with reference to the photothermal physical property of the material. Such a result is lower than the state-of-the-art of NO sensors proposed in literature, where hundreds of parts per trillion-level detection seem to have been achieved, but comparable with the performance obtained by commercial devices. The main advantages of the new device are in terms of footprint (=150 μm2), smaller at least 1 order of magnitude than those in literature, fast response time (only few seconds), and potential low cost. Such properties make possible in a handheld device the sensor integration in a multi-analysis system for detecting the presence of several trace gases, improving prevention, and reducing the duration of drug treatment for asthma and viral infections.

A novel graphene-based photonic device with two graphene monolayers sandwiched by two vertically-stacked microring resonators has been proposed. The integration of graphene allows an efficient tuning of electronic and optical properties of the resonant cavity by applying low values of voltage, minimizing the values of switching energy and switching time. This feature and the small footprint demonstrate the suitability of the proposed resonant cavity to be used as an efficient phase-shifter or a delay line. A detailed analysis of the state-of-the-art of the optical microcavities used to control and manipulate the properties of light has been also discussed to compare the performance of the proposed graphene-based vertically-stacked microring resonators with the results already proposed in literature. A maximum group delay τ g = 360 ps with a tuning range Δτ g = 230 ps, and a switching energy E switch = 26 pJ have been calculated, which confirm a high performance of the graphene-based resonant cavity with an ultra-compact footprint of 1600 µm2.

The ability to confine light at the nanoscale continues to excite the research community, with the ratio between quality factor Q and volume V, i.e., the Q/V ratio, being the key figure of merit. In order to achieve strong light-matter interaction, however, it is important to confine a lot of energy in the resonant cavity mode. Here, we demonstrate a novel cavity design that combines a photonic crystal nanobeam cavity with a plasmonic bowtie antenna. The nanobeam cavity is optimised for a good match with the antenna and provides a Q of 1700 and a transmission of 90%. Combined with the bowtie, the hybrid photonic-plasmonic cavity achieves a Q of 800 and a transmission of 20%, both of which remarkable achievements for a hybrid cavity. The ultra-high Q/V of the hybrid cavity is of order of 106 (λ/n)−3, which is comparable to the state-of-the-art of photonic resonant cavities. Based on the high Q/V and the high transmission, we demonstrate the strong efficiency of the hybrid cavity as a nanotweezer for optical trapping. We show that a stable trapping condition can be achieved for a single 200 nm Au bead for a duration of several minutes (ttrap > 5 min) and with very low optical power (Pin = 190 μW).

A novel photonic-plasmonic device with a 1D PhC dielectric cavity vertically coupled to a metal slot has been discussed. The device performance has been compared with the state-of the-art of micro-cavities, demonstrating a remarkable improvement of Q/V (= 10 7 (λ/n) -3 ) with respect to results reported in literature. A strong lightmatter interaction has been observed, making the cavity suitable for optical trapping, particularly. Strong optical forces, high stiffness and stability of the optical traps are expected in the slotted structure due to the ultra-high Q/V of the properly designed hybrid cavity, allowing the trapping of atoms and nanoparticles, such as proteins and DNA sections, and making the device suitable for interesting applications in oncology and proteomics.

The development of a high-performance DFB laser compatible with the CMOS technology is essential for the future development of silicon photonics. In this paper the preliminary results on modelling and design of a distributed feedback silicon laser are reported. The gain medium, which is a layer of erbium doped silicon-rich silicon oxide, is embedded in a horizontal slot waveguide. The designed device includes a grating with 140 periods and a quarter-wave phase shift at the grating middle. The threshold gain coefficient of the laser is 0.4 cm -1 and the emission wavelength is very close to 1.55 μm.

In the last few years, the resonant micro-optical gyroscope (RMOG) is gaining an increasing interest especially due to its features in terms of size, mass, power consumption, and cost. In this context, we are working on the demonstration of the first InP photonic gyroscope-on-chip based on the RMOG configuration. In this paper some recent advances are reported, with specific emphasis on the readout optoelectronic circuit and the preliminary results of the system test. Backscattering noise mitigation through the carrier suppression is discussed on the basis of experimental results.

Low-cost chip-scale optoelectronic gyroscopes having a resolution ≤ 10 °/h and a good reliability also in harsh environments could have a strong impact on the medium/high performance gyro market, which is currently dominated by well-established bulk optical angular velocity sensors. The R&D activity aiming at the demonstration of those miniaturized sensors is crucial for aerospace/defense industry, and thus it is attracting an increasing research effort and notably funds. In this paper the recent technological advances on the compact optoelectronic gyroscopes with low weight and high energy saving are reviewed. Attention is paid to both the so-called gyroscope-on-a-chip, which is a novel sensor, at the infantile stage, whose optical components are monolithically integrated on a single indium phosphide chip, and to a new ultra-high Q ring resonator for gyro applications with a configuration including a 1D photonic crystal in the resonant path. The emerging field of the gyros based on passive ring cavities, which have already shown performance comparable with that of optical fiber gyros, is also discussed.

In the last few years the interest towards miniaturized gyroscopes for aerospace & defence applications is quickly growing. In this context the development of a photonic gyroscope-on-chip based on the InP technology, which is increasing its maturity level, seems to be very promising. After the design, fabrication, and optical characterization of an InP gyro-oriented ring resonator with a performance improving the state-of-the-art of one order of magnitude, the development activity is now focused on the sensor readout electronics and the system test. Recently a test bench including the InP cavity, a two-channels lock-in amplifier, a custom electronic board, and other optical and optoelectronic off-the-shelf components has been set up. Some preliminary results of the system test are reported in this paper. A carrier suppression which is appropriate for the backscattering noise mitigation has been achieved and the sensor functionality has been experimentally proved.

Miniaturization of the currently available medium- and high-performance angular velocity sensors is crucial for aerospace and defense industry. To face this technological challenge, we are investigating a new gyro, called gyroscope-on-chip (GoC), based on the InP photonic integrated circuits technology. The sensor we refer includes a passive ring resonator with a Q greater than one million and several optical/optoelectronic components all monolithically integrated on a single InP chip. Recent progress on the demonstration of the GoC is reported in this paper. In particular, the configuration of the readout circuit and the countermeasures against the backscattering noise are discussed.

We present a novel configuration of photonic/plasmonic microcavity with a 1D photonic crystal cavity (PhC) vertically coupled to a metal slot. A strong light-matter interaction is allowed, due to a strong photons confinement in the metal slot, which corresponds to a low mode volume (V = 2×10 -3 (λ/n) 3 ). A Q-factor of 2.6×10 3 has been obtained, providing a ultra-high Q/V = 1.3×10 6 (λ/n) -3 , with a resonance transmission of 48 % λ = 1563.70 nm. Accurate 3D Finite Element Method (FEM) simulations have been performed to design the cavity. Optical trapping has been identified as the most suitable application for the proposed device, due to a strong gradient of the light field in the metal slot that allows high values of optical force and, consequently, the ability to trap nanoparticle with a diameter less than 100 nm.

A low-cost polymer integrated optical filter for coarse wavelength division multiplexing systems has been modelled, designed and optimized. The device, which can be manufactured by nanoimprinting lithography, is a Fabry-Perot cavity working at 1551 nm and consisting of a membrane-type slab photonic crystal in which a hole row perpendicular to the propagation direction is removed to form the two reflectors. The dependence of the resonator performance on the key geometrical parameters, i.e. the hole radius and the defect length, has been investigated by the finite element method. A good agreement between the requirements due to the specific application and the device performance has been obtained. The optimized filter, with a footprint of 43.7 μm2, has a Q-factor of 115 and a resonance transmission > 50%.

A new graphene-based flexible solar cell with a power conversion efficiency >10% has been designed. The environmental stability and the low complexity of the fabrication process are the two main advantages of the proposed device with respect to other flexible solar cells. The designed solar cell is a graphene/silicon Schottky junction whose performance has been enhanced by a graphene oxide layer deposited on the graphene sheet. The effect of the graphene oxide is to dope the graphene and to act as anti-reflection coating. A silicon dioxide ultrathin layer interposed between the n-Si and the graphene increases the open-circuit voltage of the cell. The solar cell optimization has been achieved through a mathematical model, which has been validated by using experimental data reported in literature. The new flexible photovoltaic device can be integrated in a wide range of microsystems powered by solar energy.

In the last few years, a significant research effort has been spent on both single ring resonators coupled to straight bus waveguides and multi-ring coupled resonators. In this paper main physical phenomena occurring in those structures and their most promising potential applications are briefly reviewed, with particular attention to the recent advances. Spectral properties of coupled rings are discussed and applications in the field of on-chip buffers for optical interconnects, nonlinear optics, angular velocity sensing, and group velocity manipulation are presented.

A novel nanophotonic waveguide for light confinement in low-index media is reported in this paper. Waveguide modal properties have been evaluated by the 3D Finite Element Method. Dependence of both confinement factor and propagation length on waveguide size has been investigated. Finally, waveguide group velocity dispersion and waveguide sensitivity have been calculated. The numerical results we have achieved demonstrate the potential of the new plasmonic hollow waveguide as the key element of integrated optical biochemical sensors.

Design, fabrication and initial characterization of large-size InGaAsP/InP ring resonators for gyro applications are reported in this paper. The devices configuration includes a ring with a radius of 13 mm and a straight bus waveguide with tapered ends. Four cavities with the same radius and different values of the bus/ring gap have been fabricated by metal-organic vapour-phase-epitaxy, standard photolithography and reactive ion etching. Characterization results show that the resonator with nominal gap = 1.444 µm has a quality factor exceeding 7×105 and resonance depth close to 10 dB.

In recent years there has been an increasing research interest aimed at the development of innovative integrated optic gyroscopes. Some authors have investigated coupled-resonator waveguiding structures formed by microrings mainly for their capability of manipulating light velocity, proposing also their application in phasesensitive optic gyroscopes. In this work we analyze the main performance parameters of an integrated optic gyroscope consisting of a three coupled ring resonator structure having different radii and coupling coefficients. The main result is the enhancement of the scale factor of the multi-ring-based gyroscope, without increasing the overall footprint, with respect to a conventional single ring resonator gyro. The final sensitivity of the gyroscope is also evaluated and compared with the conventional integrated optic gyroscope configuration.

An integrated optical gyroscope based on a passive silica-on-silicon resonator with a footprint of about 20 cm2 is reported in this paper. The optical characterization of the cavity has been carried out and the main experimental results are discussed. We derive the sensor performance in terms of minimum detectable angular velocity (or resolution) δΩ, underlining also the impact of the insertion loss in the silica-on-silicon device. Finally, we describe some technical approaches for improving the resolution.

Design of an optoelectronic sensor allowing the estimation of two E-field components is illustrated in this paper. The lithium niobate device, which includes two Mach-Zehnder modulators, an integrated beam splitter, and a segmented electrode antenna, has a minimum detectable field < 1 mV/m and a bandwidth of about 8 GHz. The sensor can be used as basic building block of an array of identical devices to survey both amplitude and phase of the field. The probe would facilitate the antenna diagnosis with the aim of improving its effectiveness. The array applications for near-field and very near-field characterization of radiating systems are briefly discussed.

In recent years there has been an increasing research interest aimed at the development of slow and fast light techniques. Because of their spectral properties, integrated optical cavities can be effectively exploited either as slow or fast light structures. While several authors demonstrated that coupled-resonator optical waveguide structures realized by micro-rings or photonic crystal cavities enable slow light generation, to date, much research effort is needed to demonstrate fast light devices. Integrated optical resonant devices for group velocity manipulation are critically reviewed in this paper. Modelling, optimization and potentiality of a resonant structure including two vertically-stacked micro-rings, recently investigated by the authors, are also discussed.

Speed manipulation of optical pulses is a very attractive research challenge enabling next-generation high-capacity all-optical communication networks. Pulses can be effectively slowed by using different integrated optical structures such as coupled-resonator waveguiding structures or photonic crystal cavities. Fast light generation by means of integrated photonic devices is currently a quite unexplored research field in spite of its crucial importance for all-optical pulse processing. In this paper, we report on the first theoretical demonstration of fast light generation in an ultra-compact double vertical stacked ring resonator coupled to a bus waveguide. Periodic coupling between the two rings leads to splitting and recombining of symmetric and anti-symmetric resonant modes. Re-established degenerate modes can form when a symmetric and an anti-symmetric mode having different resonance order exhibit the same resonance wavelength. Under degenerate mode conditions, wide wavelength ranges where the group velocity is negative or larger than the speed of light in vacuum are generated. The paper proves how this physical effect can be exploited to design fast light resonant devices. Moreover, conditions are also derived to obtain slow light operation regime.

A very compact (device area around 40 μm2) optical ammonia sensor based on amicroring resonator is presented in this work. Silicon-on-insulator technology is used insensor design and a dye doped polymer is adopted as sensing material. The sensor exhibitsa very good linearity and a minimum detectable refractive index shift of sensing materialas low as 8x10-5, with a detection limit around 4 ‰.

Hollow core waveguides employing anti-resonance principle have the capability to confine the optical field in a low index medium. This characteristic can be effectively employed to build very sensitive optical sensors for biochemical and environmental applications. In this paper, a micrometer guiding structure in silicon technology is investigated, providing modal analysis and sensitivity analysis. All the results are obtained by Finite Element Method numerical simulations.

In this paper, we present the modeling and design of a new approach to detect an analyte for biochemical and biological sensing applications. It is based on a whispering-gallery-mode optical resonator coupled with a Fabry-Perot cavity in silicon-on-insulator technology. The theoretical model of the whole architecture includes the influence of all electrical and optical parameters, such as thin oxide thickness, silicon and poly silicon doping concentration, optical losses, wavelength and amplitude characteristics of the architecture, charge accumulation effects, and thermal effects. The very high sensitivity of this device, demonstrated by simulations, is due to the simultaneous influence of the two coupled resonators and the metal-oxide-semiconductor structure.

In this paper, we review the different configurations proposed for electromagnetic field optical sensing. Intrinsic and extrinsic optical fiber sensors for electric and magnetic field measurement are examined, including those realized jacketing the fiber by magnetostrictive, conductive, electrochromic and polymeric materials and those measuring induced strain by magnetostrictive, electrostrictive and piezoelectric transducers. Extrinsic optical fiber sensors exploiting magneto-optic, electro-optic and Joule effects are also presented. Moreover, integrated optical electric and magnetic field sensors in which microwave signal provided by an antenna modulates the optical signal generated by an optical source are reviewed. Finally, active and coupled resonators based on electric field sensors are investigated.

In this work, the design and simulation of a high speed (300 GHz) electro-optic modulator operating at 1550-nm wavelength is presented. As electro-optic active material, a nonlinear optical polymer with highly nonlinear chromophores dispersed in an amorphous polycarbonate is used. Optimization of modulator geometrical structure and extraction of device performance parameters are obtained by 3D simulations. Finite Element Method has been exploited for the solution of Laplace equation to calculate the microwave properties of polymer-based modulator and to design its electrodes. The modeling procedure has been validated by comparison with experimental results presented in literature.

The experimental results of the system test of an optical resonant passive gyroscope based on a high Q -factor ring resonator in InP technology are reported. The open loop configuration based on the phase modulation was preferred among the analyzed configuration options, especially because it is potentially suitable for the monolithic integration of the entire sensor on a single chip. The setup components are described with a special emphasis on a custom digital readout board based on a field-programmable gate array. The board processes the input signals according to the proportional-integral algorithm which has been implemented through an optimized firmware. For the system test, the sensor rotation has been simulated using two properly driven acousto-optic modulators. The results reported here prove the gyro functionality and are a good starting point for the full development of the sensor.

Here, we report the guidelines to be followed to optimize the design of a new angular velocity sensor based on an indium phosphide (InP) ring resonator. Optical properties of InP ring resonators have been investigated together with some significant physical effects for improving the sensor sensitivity. Three-dimensional algorithms have been utilized for the theoretical estimation of the waveguide loss. An optimized waveguide with propagation loss

An InP ring resonator with an experimentally demonstrated quality factor (Q) of the order of 106 is reported for the first time. This Q value, typical for low loss technologies such as silica-on-silicon, is a record for the InP technology and improves the state-of-the-art of about one order of magnitude. The cavity has been designed aiming at the Q-factor maximization while keeping the resonance depth of about 8 dB. The device was fabricated using metal-organic vapour-phase-epitaxy, photolithography and reactive ion etching. It has been optically characterized and all its performance parameters have been estimated. InP waveguide loss low as 0.45 dB/cm has been measured, leading to a potential shot noise limited resolution of 10 degrees/h for a new angular velocity sensor.

Antimicrobial resistance (AMR) is the ability of bacteria to become immune to antimicrobial treatments and it is going to become the main cause of death in the next decades. The diagnostic techniques usually used to define the most suitable antibiotics require long time delay and also provide a resolution that is not suitable to detect multibacterial diseases. Here, we propose an optoelectronic approach for the analysis and monitoring of susceptibility and activity at the single-bacteria level. The system is realized by an array of optical tweezers for trapping of individual bacteria with high stability and trapping time of few hours, so enabling the monitoring of bacteria metabolism during the antibiotics action. We predict a high electrical detection resolution with a current variation by up to a factor 12 between dead and live bacteria allowing a real-time, reusable, label-free and nondestructive analysis on a very compact footprint, making the method suitable for on-chip integration and eventual incorporation into hand-held medical instruments.