scholarly journals Analysing the impact of non-parallelism in Fabry-Pérot etalons through optical modelling

2021 ◽  
Author(s):  
Dylan Marques ◽  
James Guggenheim ◽  
Peter Munro
Keyword(s):  
Optical Modelling ◽  
Fabry Perot ◽  
The Impact

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.

Analysis of the Impact of Temperature on the Performance of Fabry-Perot LiNbO3Electro-Optical Switch

Applied laser ◽  
2011 ◽  
Vol 31 (5) ◽  
pp. 439-442
Author(s):  
付博 Fu Bo ◽  
张大勇 Zhang Dayong ◽  
罗飞 Luo Fei ◽  
骆永全 Luo Yongquan ◽  
沈志学 Shen Zhixue
Keyword(s):  
Optical Switch ◽  
Fabry Perot ◽  
The Impact

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

Reflectivity Modelling of All-Porous-Silicon Distributed Bragg Reflectors and Fabry-Perot Microcavities

2005 ◽  
Vol 10 (1) ◽  
pp. 83-91 ◽  
Author(s):  
N. Samuolienė ◽  
E. Šatkovskis
Keyword(s):  
Porous Silicon ◽  
Wavelength Range ◽  
Active Layer ◽  
Optical Parameters ◽  
Bragg Reflectors ◽  
Distributed Bragg Reflectors ◽  
Bragg Mirror ◽  
Number Of Layers ◽  
Fabry Perot ◽  
The Impact

Herein, the problem of nanocrystaline silicon laser and its importance in microelectronics are discussed upon. The features of vertical Fabry-Perot microcavities made on the base of porous silicon are described. The responses of the reflectivity of the distributed reflection Bragg mirrors and Fabry-Perot microcavities were found using transfer matrixes method for this purpose. Inherent optical parameters of porous silicon, deposited by electrochemical etch, were used in the calculations. The calculation of the reflectivity of the distributed reflection Bragg mirrors with front active layer of nanostructural porous silicon had been examined. In the second part, the features of Fabry-Perot microcavities on variation of the number of layers of the front or rear mirrors are described. The impact of the thickness of the active nanocrystaline silicon spacer between two distributed reflection Bragg mirrors upon the spectra of optical reflectivity of Fabry-Perot microcavities in the wavelength range of 0.4–0.9 µm had been examined as well. The made conclusions are important for improvement of the thickness of the active porous silicon spacer in front of Bragg mirror and the features of Fabry-Perot microcavities.

Neural Network Processing of Optical Fiber Sensor Signals for Impact Location

1994 ◽  
Vol 360 ◽  
Author(s):  
Paul M. Schindler ◽  
John K. Shaw ◽  
Russell G. May ◽  
Richard O. Claus
Keyword(s):  
Neural Network ◽  
Optical Fiber Sensor ◽  
Back Propagation ◽  
Strain Sensors ◽  
Time Data ◽  
Impact Location ◽  
Fabry Perot ◽  
Sensor Signals ◽  
Propagation Network ◽  
The Impact

AbstractA system to detect and locate impacts by foreign bodies on a surface was developed and tested. Fiber optic extrinsic Fabry-Perot interferometer (EFPI) strain sensors were attached to or embedded in the surface, so that stress waves emanating from an impact could be detected. By employing an artificial neural network to process the sensor outputs, the impact location could be inferred to centimeter range accuracy directly from the arrival time data. In particular, the network could be trained to determine impact location regardless of material anisotropy. Results demonstrate that a back-propagation network identifiesimpact location for an anisotropic graphite/bismaleimide plate with the same accuracy as that for an isotropic aluminum plate.

scholarly journals Report of High Temperature Measurements with a Fabry-Perot Extensometer

2020 ◽  
Vol 225 ◽  
pp. 01011
Author(s):  
G. Cheymol ◽  
A. Verneuil ◽  
P. Grange ◽  
H. Maskrot ◽  
C. Destouches
Keyword(s):  
High Temperature ◽  
Reactor Core ◽  
Young Modulus ◽  
Neutron Radiation ◽  
Physical Parameters ◽  
Useful Signal ◽  
Compact Size ◽  
Fabry Perot ◽  
Radiation Induced ◽  
The Impact

Fabry-Perot (FP) sensors like other Fiber Optic (FO) sensors may be of particular interest for in pile experiments in MTR with little room available thanks to their compact size. Light weight also reduces gamma heating hence limiting the thermal effect. Different physical parameters such as temperature, strain, displacement, vibration, pressure, or refractive index may be sensed through the measurement of the optical path length difference in the cavity. We have developed a Fabry-Perot extensometer able to operate at high temperature (up to 400°C), under a high level of radiation (neutron and gamma flux). The measurement based on interferometry is largely insensitive to radiation induced attenuation (RIA) thanks to the wavelength encoding of the useful signal, but for such high fluence as encountered in a reactor core, a special rad-hard fiber is needed. Operating in the wavelength domain around 1ím remains preferable to minimize the impact of irradiation. Moreover, fast neutron radiation is expected to change the structure of the fiber and possibly others materials in the transducer. Then, we revised the basic scheme of Extrinsic Fabry-Perot Interferometer (EFPI) so that the effects of compaction remain limited. Tests under mixed neutron and gamma irradiation permitted to verify the general behavior and particularly the low drift with radiation induced compaction (RIC). Also, two types of tests have been conducted to verify the accuracy at high temperature. The first ones are “measurements” of thermal dilatation of materials: the sensor is fixed on a sample and knowing its thermal expansion, it is possible to predict the measurement expected from the optical sensor when the temperature is increased from low to high temperature. The comparison between the predicted and experimental outputs informs on how the sensor is accurate. The second types are tests on a tensile test bench operating at high temperature. The Fabry-Perot measurements are compared, in the elastic domain, with the expected strain given by the Young modulus of the material, and also on a larger strain domain, with the measurements of a high temperature axial extensometer. Both types of tests are presented and commented.

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