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Last Updated: Friday, 06 October 2017 12:30

Written by Chavdar Slavov

General Features and Structure

OPTIMUS was developed using the Matlab programing language (MathWorks, Inc.) and taking advantage of a number of available toolboxes (e.g. Optimization, Global Optimization, Statistics, Parallel Computing, GUIDE (GUI building) and Matlab compiler).

OPTIMUS has a modular structure with a common computation routine for all analysis methods (see figure below) that allows extending the program without significant alterations of the core. The fitting of the experimental data is realized by minimizing the square of the residual norm using the non-linear least square MATLAB function lsqnonlin and employing the trust-region-reflective algorithm. Since the gradient based algorithm could be trapped in a local minimum on the solution surface of multidimensional problems such as the ones typically analyzed, OPTIMUS includes a possibility to search for the global minimum of the solution surface by employing the algorithm provided by the Global optimization toolbox of Matlab. Furthermore, OPTIMUS employs the Parallel computing toolbox to speed up the solution space exploration by distributing the computations to different CPUs.

OPTIMUS-GLA & LDA

Currently, the modules OPTIMUS-GLA & LDA is available as a standalone application with an intuitive GUI for free download and use under the specified EULA. The OPTIMUS-GLA & LDA modules includes the following tools:

• tool for averaging time-resolved traces (scans) with outlier correction capabilities;
• tool for combining and subtracting different datasets as wells as for performing anisotropy calculations;
• tool for analysis of coherent artifact effects in ultrafast transient absorption experiments;
• tool for performing Global Lifetime Analysis (GLA) of time-resolved data. In the case of ultrafast experiments the GLA can be performed simultaneously with chirp and coherent artifact analysis.
• tool for performing Lifetime Density Analysis (LDA) of time-resolved data. In the case of ultrafast experiments the LDA can be performed simultaneously with chirp and coherent artifact analysis.

The use of the standalone application is straightforward (all relevant details on the analysis techniques are given in Slavov et al.), however, a brief documentation is provided to help the users. Please note, to use the standalone application you will have to download and install the royalty free Matlab Compiler Runtime (MCR) as described on the download page.

Future

The building of GUIs for the different modules is time-demanding and some of the available capabilities of OPTIMUS have not been added to the standalone application yet. However, I hope to be able to provide them soon. Furthermore, OPTIMUS was developed with the idea to be a dynamic data analysis environment and thus its development will continue with the implementation of new features. 

Details in:

Implementation and evaluation of data analysis strategies for time-resolved optical spectroscopy

Chavdar Slavov, Helvi Hartmann, Josef Wachtveitl, Analytical Chemistry, 2015, 87, 2328