Embedded-FBG ultrasonic sensing: interrogator configuration comparison

This dataset contains time-domain measurements of ultrasonic responses detected by an embedded fiber Bragg grating (FBG) sensor inside a resin cylindrical specimen. The specimen contains two embedded piezoelectric transducers (PZTs) located at both ends for ultrasonic actuation and reception, and one FBG centered along the cylinder axis (nominal Bragg wavelength λB ≈ 1551.2 nm). The PZT actuation is driven by an arbitrary waveform generator (AWG) and electrical amplifier and is time-synchronized with optical acquisition.

The goal of the dataset is to compare the measured electrical outputs obtained from multiple FBG interrogator configurations, including two baseline layouts: (a) broadband light source (BLS) + EDFA + optical circulator + embedded FBG + tunable optical filter + photodiode1, and (b) tunable laser source + optical circulator + embedded FBG + optical attenuator + photodiode2, as well as additional variants formed by combining/removing components (e.g., with/without optical amplification, with/without tunable filter).

Data organization: All files are contained under the top-level folder “Optical_FBG_Interrogator_Measurements_Datasets/”, which includes five acquisition groups “DataSet1/” to “DataSet5/”. Each DataSet folder contains (i) “PZT_TX” and “PZT_RX” (electrical oscilloscope traces of actuator drive and received PZT response), (ii) multiple Excel-compatible time-series files corresponding to different interrogator configurations (photodiode/acquisition output), and (iii) supporting metadata such as “Configuration” (text file; includes key settings when available, e.g., laser wavelength, embedded FBG Bragg wavelength, filter center wavelength, oscilloscope sampling/record settings, averaging) and “Actuation_Direction” (image). Some datasets also include the AWG waveform file (e.g., “generated_sine_hamming.arb”) and/or additional subfolders (e.g., tunable-laser related auxiliary data).

File naming convention (within each DataSet): configuration files encode the optical chain using compact tags. Common prefixes include “BLS_” for broadband-source-based interrogation and “TunableLaser_” or “TL_*” for tunable-laser-based interrogation. Mid-tags such as “Amp/NoAmp” indicate whether optical amplification (e.g., EDFA stage) was enabled; tags such as “Filter/TF/NoFilter/OF” indicate whether a tunable optical filter (or related filter condition) was present/enabled. Suffixes such as “_PD1” and “_PD2” indicate the photodiode/acquisition path used. Filenames starting with “NoSource/NoBLS/NoLightSource” correspond to control measurements with optical illumination disabled (background/noise reference).