A Wireless Photonic Intraocular Pressure Sensor

2017 ◽  
Author(s):  
Maurizio Manzo ◽  
Omar Cavazos
Keyword(s):  
Intraocular Pressure ◽  
Sensing Element ◽  
Optical Cavities ◽  
Photonic Sensor ◽  
Optical Resonances ◽  
Frustrated Total Internal Reflection ◽  
Light Coupling ◽  
Optical Modes ◽  
Micro Cavity ◽  
Quality Factor Q

In this paper, we propose analytical and numerical experiments to investigate the feasibility of a wireless photonic sensor for measuring the intraocular pressure (IOP). The sensing element is a polymeric cavity embedded into a thin layer of biocompatible material integrated to a soft contact lens. The sensor concept is based on the morphology dependent resonance (MDR) phenomenon. Changes in the eye pressure perturb the micro-cavity morphology, leading to a shift in the optical modes. The IOP is measured by monitoring the shift of optical resonances. The sensor-light coupling is made through the evanescent field by using an optical prism. Therefore, the sensor can be powered and monitored wirelessly by using frustrated total internal reflection (FTIR) of a polymeric dielectric cavity. Usually, micro-optical cavities exhibit a very high quality factor Q; thus, sensors based on MDR phenomenon exhibit high resolution. Therefore, by recording tiny variations of IOP is possible to gain more knowledge about the start, comportment, and evolution of glaucoma disease.

A Novel Microlaser Based Plasmonic-Polymer Hybrid Resonator

2018 ◽  
Author(s):  
Maurizio Manzo ◽  
Ryan Schwend
Keyword(s):  
Emission Spectrum ◽  
Metallic Nanoparticles ◽  
Laser Dye ◽  
Whispering Gallery ◽  
Polymer Hybrid ◽  
Optical Modes ◽  
Power Threshold ◽  
Micro Cavity ◽  
Quality Factor Q ◽  
Wgm Resonators

Whispering gallery mode (WGM) resonators exhibit high quality factor Q and a small mode volume; they usually exhibit high resolution when used as sensors. The light trapped inside a polymeric micro-cavity travels through total internal reflection generating the whispering gallery modes (WGMs). A laser or a lamp is used to power the microlaser by using a laser dye embedded within the resonator. The excited fluorescence of the dye couples with the optical modes. The optical modes (laser modes) are seen as sharp peaks in the emission spectrum with the aid of an optical interferometer. The position of these optical modes is sensitive to any change in the morphology of the resonator. However, the laser threshold of these microlasers is of few hundreds of microjoules per square centimeter (fluence) usually. In addition, the excitation wavelength’s light powering the device must be smaller than the microlasers size. When metallic nanoparticles are added to the microlaser, the excited surface plasmon couples with the emission spectrum of the laser dye. Therefore, the fluorescence of the dye can be enhanced by this coupling; this in turn, lowers the power threshold of the microlaser. Also, due to a plasmonic effect, it is possible to use smaller microlasers. In addition, a new sensing modality is enabled based on the variation of the optical modes’ amplitude with the change in the morphology’s microlaser. This opens a new avenue of low power consumption microlasers and photonics multiplexed biosensors.

scholarly journals Light guiding and optical resonances in ZnS microstructures doped with Ga or In

2015 ◽  
Vol 3 (42) ◽  
pp. 10981-10989 ◽  
Author(s):  
B. Sotillo ◽  
P. Fernández ◽  
J. Piqueras
Keyword(s):  
Whispering Gallery Modes ◽  
Optical Cavities ◽  
Optical Resonances ◽  
Whispering Gallery ◽  
Fabry Perot

In this work, the resonant (Fabry–Pérot and whispering gallery) modes in optical cavities based on ZnS microstructures have been studied.

Bone-Integrated Optical Microlasers for In-Vivo Diagnostic Biomechanical Performances

2019 ◽  
Author(s):  
Omar Cavazos ◽  
Maurizio Manzo ◽  
Erick Ramírez-Cedillo ◽  
Hector R. Siller
Keyword(s):  
Structural Integrity ◽  
Diagnostic Technique ◽  
Local Strain ◽  
Daily Basis ◽  
Sensing Element ◽  
Optical Resonances ◽  
Whispering Gallery ◽  
Integrated Optical ◽  
Working Principle

Abstract Bones experience mechanical loads on a daily basis. It is difficult to obtain biomechanical performances in-vivo measurements. When implants are integrated with bones after surgery, especially in aged individuals, their osseointegration can compromise the structural integrity of bones; for this reason, it is important to monitor the evolution of the mechanical properties of bones with some in-vivo diagnostic technique. In this study, we propose to integrate optical microsensing devices into bones. To simulate the working principle, a sensor is integrated with a 3-D printed bone. The sensing element is a dye-doped optical microlaser based on the morphology dependent resonance (MDR) shifts also called the whispering gallery mode phenomenon (WGM). When the microlaser is excited by a light source, the fluorescence from the dye couples with the optical resonances. These optical resonances are very sensitive to any perturbation of the microlasers’s morphology. Therefore, the local strain variation of the bone can be related to the shift of the optical resonances. This in-vivo technique monitors the biomechanical performance of bones with implants and prosthetics.

scholarly journals Polariton hyperspectral imaging of two-dimensional semiconductor crystals

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Christian Gebhardt ◽  
Michael Förg ◽  
Hisato Yamaguchi ◽  
Ismail Bilgin ◽  
Aditya D. Mohite ◽  
...  
Keyword(s):  
Hyperspectral Imaging ◽  
Transition Metal Dichalcogenides ◽  
Binding Energies ◽  
Strong Coupling Regime ◽  
Two Dimensional ◽  
Strong Light ◽  
Optical Cavities ◽  
Metal Dichalcogenides ◽  
High Level ◽  
Micro Cavity

Abstract Atomically thin crystals of transition metal dichalcogenides (TMDs) host excitons with strong binding energies and sizable light-matter interactions. Coupled to optical cavities, monolayer TMDs routinely reach the regime of strong light-matter coupling, where excitons and photons admix coherently to form polaritons up to room temperature. Here, we explore the two-dimensional nature of TMD polaritons with scanning-cavity hyperspectral imaging. We record a spatial map of polariton properties of extended WS2 monolayers coupled to a tunable micro cavity in the strong coupling regime, and correlate it with maps of exciton extinction and fluorescence taken from the same flake with the cavity. We find a high level of homogeneity, and show that polariton splitting variations are correlated with intrinsic exciton properties such as oscillator strength and linewidth. Moreover, we observe a deviation from thermal equilibrium in the resonant polariton population, which we ascribe to non-Markovian polariton-phonon coupling. Our measurements reveal a promisingly consistent polariton landscape, and highlight the importance of phonons for future polaritonic devices.

scholarly journals Extended bound states in the continuum in a one-dimensional grating implemented on a distributed Bragg reflector

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Emilia Pruszyńska-Karbownik ◽  
Mikołaj Janczak ◽  
Tomasz Czyszanowski
Keyword(s):  
Refractive Index ◽  
Bound States ◽  
High Refractive Index ◽  
Bragg Reflector ◽  
Distributed Bragg Reflector ◽  
Optical Cavities ◽  
One Dimensional ◽  
Optical Modes ◽  
High Degree ◽  
The Continuum

Abstract Bound states in the continuum (BICs) are observed in optical cavities composed of a high refractive index periodic structure embedded in significantly lower refractive index surroundings, enabling vertical confinement of the grating modes. Here, we propose a vertically nonsymmetric configuration, implemented on a high refractive index bulk substrate with a one-dimensional grating positioned on a distributed Bragg reflector (DBR). In this configuration, the grating modes are leaky, which could prohibit the creation of a BIC if the grating was implemented on uniform substrate. However, the judiciously designed DBR on which the grating is implemented reflects nonzero diffraction orders induced by the grating. We found that the laterally antisymmetric optical modes located at the center of the Brillouin zone of this structure create BICs that are robust against changes in the grating parameters, as long as the DBR reflects the diffraction orders. The configuration enables a high degree of design freedom, facilitating the realization of very high quality factor cavities in conventional all-semiconductor technology.

High tunability and sensitivity of 1D topological photonic crystal heterostructure

2021 ◽  
Author(s):  
Sayed Elshahat ◽  
Zain Elabdeen A. Mohamed ◽  
Mohamed Almokhtar ◽  
Cuicui Lu
Keyword(s):  
Photonic Crystal ◽  
Defect Mode ◽  
High Sensitivity ◽  
Edge State ◽  
Defect Layer ◽  
Glucose Sensing ◽  
Photonic Sensor ◽  
High Tunability ◽  
Interface Layers ◽  
Quality Factor Q

Abstract A modality to high tunability and sensing performance of one-dimensional (1D) topological photonic crystal (PC) heterostructure is realized based on a new mechanism through 1D topological PC. With inserting a defect aqueous layer as a sandwich between two 1D PCs, the transmittance gradually decreases with the increasing thickness of the defect layer. When the two layers of the topological heterostructure interface are replaced by the defect layer, the tunability, all sensing capabilities have been improved and the principle of topology is preserved. A topologically protected edge state is formed at the heterostructure interface with a highly localized electric field. For glucose sensing, high sensitivity S = 603.753 nm/RIU is obtained at the low detection limit of about DL = 1.22×10^(-4) RIU with high-quality factor Q = 2.33×10^4 and a high figure of merit FOM = 8147.814 RIU^(-1). Besides, the transmittance can be maintained more than 99% at low and/or high glucose concentrations, due to the coupling topological edge mode between defect mode and topological edge state. An excellent platform is examined for the design of a topological photonic sensor which is a flexible platform that can be used for any type of sensor solely by replacing the interface layers with the sensor materials. Thus, our results will promote the development of 1D topological photonic devices.

scholarly journals Mathematical Model for Electric Field Sensor Based on Whispering Gallery Modes Using Navier’s Equation for Linear Elasticity

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Amir R. Ali ◽  
Mohamed A. Kamel
Keyword(s):  
Mathematical Model ◽  
Electric Field ◽  
Linear Elasticity ◽  
Transmission Spectrum ◽  
Applied Electric Field ◽  
Sensing Element ◽  
Optical Resonance ◽  
Whispering Gallery ◽  
Electric Field Sensor ◽  
Optical Modes

This paper presents and verifies the mathematical model of an electric field senor based on the whispering gallery mode (WGM). The sensing element is a dielectric microsphere, where the light is used to tune the optical modes of the microsphere. The light undergoes total internal reflection along the circumference of the sphere; then it experiences optical resonance. The WGM are monitored as sharp dips on the transmission spectrum. These modes are very sensitive to morphology changes of the sphere, such that, for every minute change in the sphere’s morphology, a shift in the transmission spectrum will happen and that is known as WGM shifts. Due to the electrostriction effect, the applied electric field will induce forces acting on the surface of the dielectric sphere. In turn, these forces will deform the sphere causing shifts in its WGM spectrum. The applied electric field can be obtained by calculating these shifts. Navier’s equation for linear elasticity is used to model the deformation of the sphere to find the WGM shift. The finite element numerical studies are performed to verify the introduced model and to study the behavior of the sensor at different values of microspheres’ Young’s modulus and dielectric constant. Furthermore, the sensitivity and resolution of the developed WGM electric filed sensor model will be presented in this paper.

IMI long-range surface plasmon Bragg micro-cavity

2016 ◽  
Vol 30 (30) ◽  
pp. 1650355 ◽  
Author(s):  
Kai Tong ◽  
Jun Wang ◽  
Chunliang Zhou ◽  
Meiting Wang
Keyword(s):  
Liquid Crystal ◽  
Quality Factor ◽  
Long Range ◽  
Surface Plasmon ◽  
Defect Mode ◽  
Defect Layer ◽  
Cavity Structure ◽  
Micro Cavity ◽  
Quality Factor Q ◽  
Photonic Energy

The defect layer is introduced to the insulator-metal-insulator (IMI) Bragg waveguide structure. The micro-cavity structure of long-range surface plasma is proposed based on the defect mode. The liquid crystal is the defect layer in the structure of Bragg. The energy band characteristics of the long-range surface plasmon Bragg micro-cavity structure are analyzed by using the finite difference time domain method. The influence of the period number and the length of the micro-cavity on the quality factor Q and the volume V of the Bragg grating are discussed. The results show that the photonic energy can be confined very well in the micro-cavity by the structure of the micro-cavity. By controlling the birefringence of liquid crystal, the resonance wavelength of the micro-cavity appears with redshift phenomenon. The tuning range is 42 nm. The tuning of the working window of the long-range surface plasmon filter is realized. The photonic energy is the strongest in the insulating layer and the metal interface. The increase of cycles number has certain limitation on the improvement of the quality factor Q of the cavity. The influence of the defect-cavity length on the resonant wavelength, the quality factor Q and the mode volume V is obvious. The performance of the micro-cavity can be improved by adjusting the number of the micro-cavity and the length of the defect-cavity, and the ratio of Q/V can reach 43,750 in the communication band. The nano micro-cavity provides a new design idea and basis for the fabrication of tunable long-range surface plasmon wave filter in this paper.

Embedded Spherical Microlasers for In Vivo Diagnostic Biomechanical Performances

2020 ◽  
Vol 3 (4) ◽  
Author(s):  
Maurizio Manzo ◽  
Omar Cavazos ◽  
Erick Ramirez-Cedillo ◽  
Hector R. Siller
Keyword(s):  
Uv Light ◽  
Bending Moment ◽  
Strain Range ◽  
Sensing Element ◽  
Poisson Effect ◽  
Optical Resonances ◽  
Strain Monitoring ◽  
Percentage Difference ◽  
Order Of Magnitude

Abstract In this article, we propose to use spherical microlasers that can be attached to the surface of bones for in vivo strain monitoring applications. The sensing element is made of mixing polymers, namely, PEGDA-700 (Sigma Aldrich, St. Louis, MO) and Thiocure TMPMP (Evan Chemetics, Teaneck, NJ) at 4:1 ratio in volume doped with rhodamine 6G (Sigma Aldrich, St. Louis, MO) laser dye. Solid-state microlasers are fabricated by curing droplets from the liquid mixture using ultraviolet (UV) light. The sensing principle relies on morphology-dependent resonances; any changes in the strain of the bone causes a shift of the optical resonances, which can be monitored. The specimen is made of a simulated cortical bone fabricated with photopolymer resin via an additive manufacturing process. The light path within the resonator is found to be about perpendicular to the normal stress' direction caused by a bending moment. Therefore, the sensor measures the strain due to bending indirectly using the Poisson effect. Two experiments are conducted: 1) negative bone deflection (called loading) and 2) positive bone deflection (called unloading) for a strain range from 0 to 2.35 × 10−3 m/m. Sensitivity values are ∼19.489 and 19.660 nm/ε for loading and unloading experiments, respectively (percentage difference is less than 1%). In addition, the resolution of the sensor is 1 × 10−3 ε (m/m) and the maximum range is 11.58 × 10−3 ε (m/m). The quality factor of the microlaser is maintaining about constant (order of magnitude 104) during the experiments. This sensor can be used when bone location accessibility is problematic.

MEMS Gyro Modal Analysis and Design Tool

2003 ◽  
Author(s):  
J. Albert Chiou
Keyword(s):  
Low Voltage ◽  
Design Tool ◽  
Consumer Electronics ◽  
Automotive Applications ◽  
Sensing Element ◽  
Analysis And Design ◽  
Development Cycle ◽  
Process Tolerance ◽  
Mechanical Element ◽  
Quality Factor Q

A gyroscope is used to measure angular rates for may applications such as automotive applications, navigation applications, military applications, consumer electronics applications, and robotics applications, etc. For our specific automotive applications, the gyro is used to sense the yaw, roll, and pitch angular rates for ride stabilization and rollover detection. The tuning-fork gyro device used is a double gimbaled vibratory gyroscope supported by flexures with the vibrating mechanical element made of silicon. In order to drive the gyro device with a low voltage and a high quality factor (Q), the sensing element is sealed in a high-vacuumed package. The operational resonant frequencies are very critical to the ASIC control circuit. The purpose of this study is to perform modal analyses, validate the simulation results with testing data, and provide a design tool for quick gyro element resonant frequency predictions in order to reduce design and product development cycle time. The process tolerance and design limit can also be quickly evaluated before the wafer is built.

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