Laser Coherence Analyzer

This software package makes sense in the context of the following downloadable scientific publication in OSA's optics express 2016 : "Time-Dependant Laser Linewidth : beat-note digital acquisition and numerical analysis", N.Von Bandel, M. Myara, M. Sellahi, T. Souici, R. Dardaillon and P.Signoret. Both software and publication can be downloaded for free. The publication is under OSA license, while the software is under BSD license. Please cite our Optics Express publication if you use this software or part of this software in the frame of scientific works or publications. Please mention the authors of this software if you reuse this code or part of this code in another software. This software package contains 3 parts, all related to the handling and analysis of sampled data obtained from laser beat-notes : LineWidthExplorerGUI : a software made to analyse the beat-note spectrum as a function of integration time. Can be time consuming or not, depending on the parameters selected for the data analysis. This software contains both a class for the data analysis part and the code for a useful GUI, that helps determining the relevant parameters for the computation of the laser linewidth as a function of time. BeatingDemodulation : a function that implements the Hilbert Transform. It performs thus the phase demodulation of the beating and allows to obtain the associated frequency noise. The software is not really complex but it gives well calibrated results (this was checked through experimental work). ConvertBigTrace : because the file data comming from acquisition software can be huge (in the publication, we had files bigger than 1 Go), we wrote a little helper tool to convert Agilent's TSC files (generated by the acquisition software coming with the Agilent U1084-001 sampler) into matlab variables. It generates matlab files containing : a "dt" field containing the sampling frequency in seconds. The Matlab type should be "double". a column vector named "Y" containing the sampled beat-note. The Matlab type should be "double" too. All this software was tested under Matlab 2014b for Macintosh and requires both Signal Analysis Toolbox as well as the Curve Fitting Toolbox. Of course it should work under Windows and Linux, as older versions of the software were implemented on these platforms. As all this software relies a lot on FFT implemetation, it should work really quickly on multicore computers, except when fitting is ativated by the user.