READ ME File For 'Scattering Media for Reconstructive Wavemeters, Interrogators and Sensors - Dataset'

Dataset DOI:  10.5258/SOTON/D2668

ReadMe Author: PRZEMYSLAW LUDWIK FALAK, University of Southampton ORCID: 0000-0002-2970-0700

This dataset supports the thesis entitled: Scattering Media for Reconstructive Wavemeters, Interrogators and Sensors
AWARDED BY: Univeristy of Southampton
DATE OF AWARD: 2024

DESCRIPTION OF THE DATA
This dataset is organised in sub-folders, titled "Chapter XX", where XX - is the corresponding chapter number in the thesis and the files are named to correspond with the given figure/data.
The data consists of exemplar speckle patterns, system stability assessment results and measurand reconstruction results.

Each data is saved as both .pdf and .fig file (where applicable, if other file format is present, the annotation will appear). 
The .pdf file can be opened by Adobe Acrobat (or any other .pdf reader). 
The .fig files are native format of MATLAB figure and were created in/can be opened with MATLAB R2021a (Mathworks). 
In addition to all visual features, by using appropriate commands within the MATLAB, the data itself can be extracted, exported or re-used, if needed. 
The exemplar instructions how to extract data from .fig files can be found here: https://www.mathworks.com/matlabcentral/answers/100687-how-do-i-extract-data-from-matlab-figures, or here: https://stackoverflow.com/questions/43553205/how-to-extract-a-matrix-from-a-fig-in-matlab

This dataset contains (if no Chapter is mentioned - no shareable data was generated for a given Chapter):

Chapter 2:
1) exemplar speckle pattern from 20cm FG105LCA MMF at 1050nm (.pdf only), 
2) scattering optimisation simulation, 
3) speckle pattern grain motif analysis for MMF and 3D scattering voids array (results as .pdf and .fig + .jpg speckles - opened with MATLAB, or IrfanView),
4) 630-650nm light source spectrum impact on the scattering array speckle pattern motifs and intensity

Chapter 3:
1) singular value decomposition (SVD) of an exemplar MMF speckle pattern dataset (341 speckles (.png), obtained from 50 cm FG105LCA MMF by tuning the wavelength in the range 1039.35 nm to 1056.40 nm with 0.05 nm increments, as .zip archive): top five eigen-speckles, singular value decay plot and the cumulative energy plot
 
Chapter 4:
1) tuneable laser source (TLS) TLK-1050M spectrum for tuning range 1035-1065 nm (Yokogawa OSA AQ6370D as reference device)
2) TLS TLK-1050M tuning mismatch in range 1040-1056 nm with the tuning step of 45 pm (Yokogawa OSA AQ6370D as reference device)

Chapter 5:
1) total number of allowed modes in the MMF as a function of increasing core radius 0.1-100 microns for 1050 nm input wavelength and NA (numerical aperture) of 0.22
2) demonstrating the V-parameter role in SMF/MMF threshold and total number of allowed modes approximation for 1050 nm input wavelength and NA=0.22
3) simulated linearly-polarised (LP) modes LP01 and LP74
4) simulated speckle patterns for varying input wavelength (1049, 1050 and 1051 nm) and fibre length (0.01m and 100m)
5) autocorrelation matrix and 1050 nm peak spectrum analysis of SNR (signal-to-noise ratio) and FWHM (full width half maximum) for 100% (613), 10% (62) and 30% (184) of allowed modes
6) FWHM-limited minimum fibre section length and equal-resolution speckles for varying % of allowed modes

Chapter 6:
1) stability test results of fixed-wavelength reconstruction form 50 cm MMF FG105LCA for 12 h, with environmental fluctuations (humidity and temperature)
2) speckle patterns for 0 h and 6 h time lapsed at 1050nm input for 50 cm FG105LCA MMF
3) reconstruction (correlation) matrices for 15cm, 30 cm and 50 cm MMF-based wavemeter in 1040-1056 nm range with ~45 pm increment step
4) geometrically distorted (single-touch) corrleation matrix and reconstructed spectrum of geometrically disturbed/undisturbed system for single-wavelength (1048.65 nm peak)
5) wavemeter spectral shapes/reconstruction characteristics for 15 cm, 30 cm and 50 cm MMF sections at 1048.65 nm peak

Chapter 8:
1) speckle patterns stability analysis (RMS difference, transformation displacement, temperature/humdity fluctuations) for 3D scattering chip in old device case
2) speckle patterns PCA (first four components) projection vs humidity and temperature to identify instability driving force
3) PCA projection vs speckle displacements for PCA1 and PCA2
4) sensor (camera) translational displacements for old and new device case design (removal cable slit)
5) fixed-wavelength 7 days (168 h) 3D chip-based wavemeter for 1048.65 nm stability test (reconstruction) and corresponding environmental conditions (temperature/humidity)
6) speckle pattern analysis (RMS difference and translational displacements) for redesigned device case (stability improvement)
7) exemplar speckle pattern (1048.65 nm) binning for binning order of 1 (unmodified) 5 and 20
8) binning impact on the correlation matrices for 1035-1065 nm (no binning, 5 and 20 binning order)
9) finding an optimal binning order vs. standard reconstruction error
10) fixed-wavelength 7 days 3D chip wavemeter stability with binning order of 5 and 20 applied
11) correlation (reconstruction) matrix for 3D chip-based wavemeter in range 1040-1056 nm: full range and close-up of 1045-1046 nm section
12) single spectral peak characteristics of 1048.65 nm for 3D chip-based wavemeter system
13) binning impact of 5th and 20th order on a synthesised twin-peaks spectrum shape
14) binning impact on synthesised sinusoidal spectra 1050-1057 nm (unbinned, 5th and 20th binning order)

Chapter 9:
1) exemplar flat fibre-generated speckle pattern at 1048.75 nm
2) flat fibre-based speckle pattern grain motif analysis + .jpg file
3) flat fibre-based scattering system fixed wavelength stability (60 h) at 1048.75nm and acompanying environmental conditions (temperature and humidity)
4) reconstruction (correlation) matrix for the flat fibre-based device in range 1040-1056 nm with ~45 pm increment and 1045-1046 nm close-up
5) flat fibre-based single peak wavemeter spectra characteristics (at 1048.65 nm)

Chapter 10:
1) laser-written point-by-point FBG characterisation spectrum (OSA Yokogawa AQ6370D as a reference) at idle 1070.05 nm and FBG linearity response (tensile strain applied vs relative wavelength shift)
2) FBG-reflected flat fibre speckles showing idle FBG (no strain), minimum strain shift (4 micorstrain) and highest tensile value applied (200 microstrain)
3) strain recovery in range 0-200 microstrains as 3 times rmping up and down for correlation equation and PCA projection
4) principal component analysis (PCA) of an exemplar flat fibre speckle pattern dataset (341 speckles (.png), obtained from flat fibre by tuning the wavelength in the range 1039.35 nm to 1056.40 nm with 0.05 nm increments, as .zip archive): top five eigen-speckles, singular value decay plot and the cumulative energy plot
5) first four PCA projection for calibration and measurment strain reconstruction datasets
6) temporal stabiity of the FBG strain measurement interrogation for 0 h, 48 h and 144 h
7) stability analysis (speckles correlation, PCA1-PCA3 projection and temperature/humidity change) of 9 FBGs superpositioned speckle pattern
8) exemplar FBG-reflected flat fibre-generated speckle pattern from single FBG and 9 FBG superposition
9) multiple FBG load reconstruction: PCA1 projection and load (kilogram-force) reconstruction for both calibration, linear ramping and random sequence

Chapter 11:
1) PCA 1 projection of linear polarisation rotation and reconstruction for: 0-1 degree range with 0.1 increment, 0-2 degree with 0.2 increment and 0-20 degree with 1 degree step
2) temporal stability of polarisation rotation reconstruction for: 0h, 48 h and 144 h
3) PCA 1 projection and magnetic field reconstruction in range 0-75 mT
4) speckle pattern RMS difference and magnetic coil temperature for: constant current of 0.1 A for 1 h and twice ramping in range 0-3.5 A with 0.1 A step
     
Chapter 12:
1) engineered metalens reflected spectra vs metalens-mirror separation (CCS100, Thorlabs as reference device) and blue-shift between reflected light peak positions and metalens-mirror separation
2) distance reconstruction and PCA1 projection in absolute range 1-1.0195 mm with stage step of 0.03 micrometers
3) distance reconstruction and PCA1 projection in absolute range 0.88-1.06 mm with stage step of 1.1 micrometers


Licence:
Creative Commons Attribution CC-BY 

Related projects/Funders:
DTP 2020-2021 University of Southampton EP/T517859/1 (Project Reference: 2448148)
UK Engineering and Physical Sciences Resarch Council (EPSRC) grants: EP/T02643X/1, EP/N00762X/1, EP/P006930/1, EP/V053213/1 and EP/S013776/1.

Related publication:
P. Falak, T. Lee, S. Zahertar et al., “Compact high-resolution FBG strain
interrogator based on laser-written 3D scattering structure in flat optical fiber,”
Sci. Rep., vol. 13, p. 8805, May 2023

Q. Sun, P. Falak, T. Vettenburg et al. “Compact nano-void spectrometer based on
a stable engineered scattering system,” Photon. Res., vol. 10, p. 2328, Oct 2022

P. Falak, J. Ho-Tin Chan, J. Williamson et al., “Chromatic confocal metalens and
scattering medium-based speckle pattern engineering for compact, low-cost
distometers,” in 28th International Conference on Optical Fiber Sensors (OFS-28),
Optica, Nov 2023

P. Falak, T. Lee, Q. Sun et al., “Magnetic field sensing using laser written
birefringent scattering medium,” in European Workshop on Optical Fibre Sensors
(EWOFS 2023), vol. 12643, p. 126432S, SPIE, May 2023

P. Falak, Q. Sun, T. Vettenburg et al., “Low-cost fiber Bragg grating interrogation
with a femtosecond laser written scattering chip,” in Laser Applications in
Microelectronic and Optoelectronic Manufacturing (LAMOM) XXVIII vol. 12408, p.
1240806, SPIE, Mar 2023

P. Falak, Q. Sun, T. Vettenburg et al., “Femtosecond laser written scattering chip
for high-resolution low-cost reconstructive spectrometry,” in Photonic
Instrumentation Engineering IX, vol. 12008, p. 120080E, SPIE, Mar 2022

M. Beresna, Q. Sun, P. Falak et al., “Laser-induced scattering structures for
metrology and distributed sensing,” in Laser Applications in Microelectronic and
Optoelectronic Manufacturing (LAMOM) XXVII, vol. 11988, p. 1198803, SPIE, Mar
2022


Date that the file was created: January, 2024