• Introduction
• Requirements
• Installation
• Features
• Copyright
• Warranty
• History
• Download
• Trademarks

Introduction

The Flex99-12C by Correlator.com is an USB single-channel auto-correlator and dual-channel cross-correlator, respectively. This MATLAB interface provides an intuitive and simple access to the correlator hardware. It features automatic storage of the sample data, live preview of the correlation curve, parameter extraction for a single component and afterpulsing suppression.

Requirements

• An Intel-based computer.
• Windows 2000 or Windows XP.
• MATLAB 6.0 or newer.
• Flex99OEM-12C USB hardware correlator and the corresponding USB driver by Correlator.com.

Installation

Unpack the archive in a folder of your choice. Install the Flex99OEM-12C driver by Correlator.com. Copy the SDK library "Flex99-12C.dll" or "Flex99OEM-12C.dll" into the private folder and rename it to "Flex99-12C.dll". Start MATLAB and call "flex99.m".

Features

• Live control

  The graphical user interface provides live control of the correlator and previews the results during acquisition. You can set-up the correlation mode (auto- or cross-correlation) and the integration time.

• Live fit

  Curve fitting is integrated to get a rough estimation of the parameters for a single, freely diffusing component. The parameters are extracted in live operation and on recordings.

• Auto-save

  By clicking on the "File name template" button, you can define a folder and a file name used as template to save the correlation automatically. A 3-digit file number is prepended and increased automatically on every save.

Figure 1: Graphical user interface to the Flex99-12C correlator

• File format

  The correlation is saved in the Zeiss/Evotec file format as used with the Confocor system. Just open the files with the corresponding fitting software for parameter extraction.

  The export function can also create MAT-files. Comment and uncomment the corresponding lines in "export.m" to change the file format.

• Afterpulsing suppression

  You can suppress afterpulsing by estimating its contribution to the auto-correlation signal in advance. The estimation is easy:

  1. Set the integraton time to at least 100s.
  2. In live mode, dim the ambient light to get about the same intensity level as during your experiment. Be sure to use an uncorrelated light source - daylight for example. Also, make sure that the intensity does not vary during the afterpulsing estimation.
  3. Click on "estimate" and decide after recording if you wish to retain the current estimation. Before accepting it, you should control if there was no drift in the light level during acquisition.
  4. Enable the static or adaptive suppression.

     Although, the adaptive suppression works well for a wide range of mean intensity levels, it is recommended to estimate the afterpulsing for a different intensities from 5kHz to 2MHz.

     To suppress afterpulsing, its estimated contribution is subtracted from the auto-correlation curve. Verify that the auto-correlation tends to a constant value for delays below 1us.

Copyright

The MATLAB interface to the Flex99-12C USB hardware correlator is published as freeware. The author reserves the right to modify any of the contained files.

You are allowed to distribute this package as long as you deliver the entire, original package for free.

You are allowed to distribute modified versions of export.m, fitcorr.m and shutter.m as an extension package. In particular, you are not allowed to distribute a combination of modified files with other parts of the original package as a single archive.

Path		File		Description
/		Flex99-12C.pdf		User manual
		flex99.m		MATLAB interface
		Readme.txt		Summary
private/		export.m		Save the correlation data to a file
		fitcorr.m		Extract the parameters
		flex99c12.dll		MATLAB interface library
		flex99c12.m		MATLAB interface help
		shutter.m		Automatic shutter control

Warranty

Any warranty is strictly refused. Don't rely on any financial or technical support in case of malfunction or damage.

Comments are welcome. I will try to track reported problems and fix bugs.

History

June 22, 2004

Initial release

September 1, 2004

Bug fixed in control.dll.

May 4, 2005

Release 1.1: A user manual was added, as well as zooming into the correlation and resizing of the main window.

May 26, 2005

Minor updates of the help file.

October 25, 2005

Release 1.2: Added a context menu to clear and hide the intensity traces.

July 19, 2006

Bug fix: substituted CPUTIME by NOW for compatibility with MATLAB 7.x.

July 19, 2008

Bug fix: file name template specification now compatible with MATLAB 7.x.

Download

Downloading these files, you accept the copyright terms.

• Flex99-12C correlator interface for MATLAB 6.0 or newer
  Digital signature

Trademarks

MATLAB is a registered trademark of The MathWorks, Inc. Windows is a trademark of Microsoft Corp. Confocor is a trademark of Carl Zeiss. Other product or brand names are trademarks or registered trademarks of their respective holders.