Studying the impact of roughness on the sensitivity of Fabry-Pérot sensors for photoacoustic imaging

2021 ◽  
Author(s):  
Dylan Marques ◽  
James A. Guggenheim ◽  
Edward Z. Zhang ◽  
Paul C. Beard ◽  
David Martin-Sanchez ◽  
...  
Keyword(s):  
Photoacoustic Imaging ◽  
Fabry Perot ◽  
The Impact

scholarly journals Towards Transabdominal Functional Photoacoustic Imaging of the Placenta: Improvement in Imaging Depth Through Optimization of Light Delivery

2021 ◽  
Author(s):  
Kristie Huda ◽  
Kenneth F. Swan ◽  
Cecilia T. Gambala ◽  
Gabriella C. Pridjian ◽  
Carolyn L. Bayer
Keyword(s):  
Delivery System ◽  
Light Propagation ◽  
Ex Vivo ◽  
Photoacoustic Imaging ◽  
Incidence Angle ◽  
Incident Angle ◽  
Placental Tissue ◽  
Light Delivery ◽  
Imaging Depth ◽  
The Impact

AbstractFunctional photoacoustic imaging of the placenta could provide an innovative tool to diagnose preeclampsia, monitor fetal growth restriction, and determine the developmental impacts of gestational diabetes. However, transabdominal photoacoustic imaging is limited in imaging depth due to the tissue’s scattering and absorption of light. The aim of this paper was to investigate the impact of geometry and wavelength on transabdominal light delivery. Our methods included the development of a multilayer model of the abdominal tissue and simulation of the light propagation using Monte Carlo methods. A bifurcated light source with varying incident angle of light, distance between light beams, and beam area was simulated to analyze the effect of light delivery geometry on the fluence distribution at depth. The impact of wavelength and the effects of variable thicknesses of adipose tissue and muscle were also studied. Our results showed that the beam area plays a major role in improving the delivery of light to deep tissue, in comparison to light incidence angle or distance between the bifurcated fibers. Longer wavelengths, with incident fluence at the maximum permissible exposure limit, also increases fluence within deeper tissue. We validated our simulations using a commercially available light delivery system and ex vivo human placental tissue. Additionally, we compared our optimized light delivery to a commercially available light delivery system, and conclude that our optimized geometry could improve imaging depth more than 1.6×, bringing the imaging depth to within the needed range for transabdominal imaging of the human placenta.

Large Plasmonic Resonance Shifts From Metal Loss in Slits

2021 ◽  
Author(s):  
Zohreh Sharifi ◽  
Reuven Gordon
Keyword(s):  
Time Domain ◽  
Finite Difference Time Domain ◽  
Single Mode ◽  
Metal Loss ◽  
Plasmonic Resonance ◽  
Reflection Phase ◽  
Past Experiment ◽  
Fabry Perot ◽  
The Impact ◽  
Difference Time

Abstract The impact of loss on the plasmonic resonances in metal-insulator­metal slits is analyzed, particularly the significant effect of loss on the reflection phase. The reflection is calculated analytically using single mode matching the­ory with the unconjugated form of the orthogonality relation. This theoretical calculation agrees well with comprehensive simulations, but differs substan­tially from the conjugated orthogonality result, as was used in past analytical works. This reflection phase has a large impact on the plasmonic resonance wavelengths, which are calculated using a Fabry-Pérot theory and compared with past experiment and finite-difference time-domain simulations.

scholarly journals ORIENTATION AND CALIBRATION REQUIREMENTS FOR HYPERPECTRAL IMAGING USING UAVs: A CASE STUDY

2016 ◽  
Vol XL-3/W4 ◽  
pp. 109-115
Author(s):  
A. M. G. Tommaselli ◽  
A. Berveglieri ◽  
R. A. Oliveira ◽  
L. Y. Nagai ◽  
E. Honkavaara
Keyword(s):  
Remote Sensing ◽  
Data Sets ◽  
Spectral Bands ◽  
Operational Problem ◽  
Fabry Perot ◽  
Agricultural Applications ◽  
Close Range ◽  
The Impact ◽  
Hyperspectral Camera

Flexible tools for photogrammetry and remote sensing using unmanned airborne vehicles (UAVs) have been attractive topics of research and development. The lightweight hyperspectral camera based on a Fabry-Pérot interferometer (FPI) is one of the highly interesting tools for UAV based remote sensing for environmental and agricultural applications. The camera used in this study acquires images from different wavelengths by changing the FPI gap and using two CMOS sensors. Due to the acquisition principle of this camera, the interior orientation parameters (IOP) of the spectral bands can vary for each band and sensor and changing the configuration also would change these sets of parameters posing an operational problem when several bands configurations are being used. The objective of this study is to assess the impact of use IOPs estimated for some bands in one configuration for other bands of different configuration the FPI camera, considering different IOP and EOP constraints. The experiments were performed with two FPI-hyperspectral camera data sets: the first were collected 3D terrestrial close-range calibration field and the second onboard of an UAV in a parking area in the interior of São Paulo State.

scholarly journals ORIENTATION AND CALIBRATION REQUIREMENTS FOR HYPERPECTRAL IMAGING USING UAVs: A CASE STUDY

2016 ◽  
Vol XL-3/W4 ◽  
pp. 109-115 ◽  
Author(s):  
A. M. G. Tommaselli ◽  
A. Berveglieri ◽  
R. A. Oliveira ◽  
L. Y. Nagai ◽  
E. Honkavaara
Keyword(s):  
Remote Sensing ◽  
Data Sets ◽  
Spectral Bands ◽  
Operational Problem ◽  
Fabry Perot ◽  
Agricultural Applications ◽  
Close Range ◽  
The Impact ◽  
Hyperspectral Camera

Flexible tools for photogrammetry and remote sensing using unmanned airborne vehicles (UAVs) have been attractive topics of research and development. The lightweight hyperspectral camera based on a Fabry-Pérot interferometer (FPI) is one of the highly interesting tools for UAV based remote sensing for environmental and agricultural applications. The camera used in this study acquires images from different wavelengths by changing the FPI gap and using two CMOS sensors. Due to the acquisition principle of this camera, the interior orientation parameters (IOP) of the spectral bands can vary for each band and sensor and changing the configuration also would change these sets of parameters posing an operational problem when several bands configurations are being used. The objective of this study is to assess the impact of use IOPs estimated for some bands in one configuration for other bands of different configuration the FPI camera, considering different IOP and EOP constraints. The experiments were performed with two FPI-hyperspectral camera data sets: the first were collected 3D terrestrial close-range calibration field and the second onboard of an UAV in a parking area in the interior of São Paulo State.

scholarly journals RELIABILITY OF THE GEOMETRIC CALIBRATION OF AN HYPERSPECTRAL FRAME CAMERA

2019 ◽  
Vol XLII-2/W13 ◽  
pp. 1701-1707
Author(s):  
M. A. Musci ◽  
I. Aicardi ◽  
P. Dabove ◽  
A. M. Lingua
Keyword(s):  
Remote Sensing ◽  
Image Processing ◽  
High Resolution ◽  
Environmental Conditions ◽  
Precision Agriculture ◽  
Focal Length ◽  
Geometric Calibration ◽  
Fabry Perot ◽  
The Impact ◽  
Orientation Parameters

<p><strong>Abstract.</strong> One of the main tools for high resolution remote sensing and photogrammetry is the lightweight hyperspectral frame camera, that is used in several application areas such as precision agriculture, forestry, and environmental monitoring. Among these types of sensors, the Rikola (which is based on a Fabry–Perot interferometer (FPI) and produced by Senop) is one of the latest innovations. Due to its internal geometry, there are several issues to be addressed for the appropriate definition and estimation of the inner orientation parameters (IOPs). The main problems concern the possibility to change every time the sequence of the bands and to assess the reliability of the IOPs. This work focuses the attention on the assessment of the IOPs definition for each sensor, considering the impact of environmental conditions (e.g., different time, exposure, brightness) and different configurations of the FPI camera, in order to rebuild an undistorted hypercube for image processing and object estimation. The aim of this work is to understand if the IOPs are stable over the time and if and which bands can be used as reference for the calculation of the inner parameters for each sensor, considering different environmental configurations and surveys, from terrestrial to aerial applications. Preliminary performed tests showed that the focal length percentage variation among the bands of different experiments is around 1%.</p>

Performance Analysis of Cantilever Beam for Tunable Fabry Perot Filter

2019 ◽  
Vol 17 (9) ◽  
pp. 739-745
Author(s):  
M. Shanmugapriya ◽  
T. Manimekalai ◽  
C. V. Gayathri
Keyword(s):  
Cantilever Beam ◽  
Electrostatic Force ◽  
Short Wave ◽  
Cavity Surface ◽  
Reflective Coating ◽  
Fabry Perot ◽  
Vertical Cavity Surface ◽  
Surface Emitting Laser ◽  
The Impact ◽  
Long Wave Infrared

The design and simulation of the cantilever beam for tunable fabry perot filter is discussed in this paper. The fabry perot filter is tuned to operate in three frequency ranges namely short wave Infrared (SWIR), mid wave Infrared (MWIR) and long wave Infrared (LWIR) are operated in the frequency range of 1.6–2.5 μm, 3–5 μm and 8–12 μm respectively. The light that is emitted from the array of vertical cavity surface emitting laser (VCSEL) is tuned to the desired wavelength using this fabry perot filter. The fabry perot cavity length is varied using the MEMS cantilever. By applying the reflective coating to the arms of the cantilever, the fabry perot cavity is formed. The actuation given to the MEMS cantilever is electrostatic actuation. The potential difference between the two arms of the cantilever creates the electrostatic force, which attracts the free end of the cantilever. Due to the impact of the electrostatic force the arms get pulled in, as a result the separation between the mirrors varies, which in turn filters the desired wavelength. The array of cantilever is also simulated to get a desired pattern of the wavelength. The fabrication process flow for the simulated cantilever is explained. The fixed-free beam approach leads to the analysis of capacitance, stress, strain and displacement.

Flexible microbubble-based Fabry–Pérot cavity for sensitive ultrasound detection and wide-view photoacoustic imaging

2020 ◽  
Vol 8 (10) ◽  
pp. 1558
Author(s):  
Jun Ma ◽  
Yang He ◽  
Xue Bai ◽  
Li-Peng Sun ◽  
Kai Chen ◽  
...  
Keyword(s):  
Photoacoustic Imaging ◽  
Fabry Perot
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