FROG Functionality and Features

FROG 3

• Fixed a bug that caused the raw data window to throw a "divide by zero" error on a small minority of machines.

• Fixed a bug that caused the projection algorithms to not converge robustly. (Bug manifested in v3.2.0).
• Fixed copy-to-clipboard and print functions for traces, and print function for field graphs.
• Fixed bug that caused an error when a strategy was deleted.

• Added axes for the temporal and spectral windows!

• Unlocked the XFROG strategies panel - edits are not ignored, they just aren't persisted. My bad.
• Fixed bug that prevented rescaling experimental data with negative time delays.

• In the Marginals tab, only the files that are needed for the particular nonlinearity are active.
• In the Marginals window, there's now a "Continue" button that you can use in lieu of the little "x".
• Added a tutorial for getting started with FROG.

• Now the trace and field windows will repaint when resized even when the algorithm is not running.

• Made the Strategy panel in XFROG uneditable, since edits are ignored in XFROG.
• Made the spectral FWHM use the exact frequency-to-wavelength conversion instead of the linear approximation (in practice, it is normally less than 1% error, except at very large wavelengths).

• Fixed bug in XFROG wizard, when using "Previous FROG Retrieval" for the reference field, and the size of the XFROG grid was larger than the reference pulse grid, a floating point error sometimes occured.
• Fixed bug where Femtosoft Compatible output FROG traces had a center wavelength that was off by one pixel.

• Added a very effective new noise subtraction algorithm (Pixel Cleanup).
• In the Marginal graph, right-clicking and selecting "Zoom In" will also recenter the graph on the point of the mouse click.
• A new output format, "Femtosoft Compatible", was added. Files output in this mode can be read in with the FROG program as experimental traces (but set "Order" to "Delay" and set "Read In As" to "Constant Frequency").

• Fixed bug that caused incorrect central wavelength in XFROG when reading in a reference field from disk.
• Fixed bug that caused incorrect central wavelength in FROG when data extraction was used with an off-center extraction area.
• Fixed some minor bugs that caused errors in the XFROG wizard under certain conditions.

• The algorithm now saves the main inputs (grid size, theory/experiment, nonlinearity) from run-to-run.
• Added display of current best error in the retrieval.
• Functionality added to force a FROG trace to agree with the experimentally measured & calculated frequency marginal.

• Bug that caused DFG XFROG to output spectra at the wrong wavelength fixed.
• Cancelling time-resampling of experimental data no longer leads to annoying error.
• The Algorithm Control form cannot be closed now by clicking the little "x".
• Fixed bug that caused Raw Data window to develop scrollbars at certain magnifications.

• The best fields are now displayed at the end of the retrieval, along with the best retrieved FROG trace.

• Corrected a missing help file.
• Fixed a bug that caused errors reading in data files where the calibration numbers were followed by a single space and a line feed.
• A bug in the data extraction routine introduced in 3.08 was corrected.

• The auto-saving of files can now be turned on or off, or you can be quizzed by the system if you are about to overwrite previous files.

• XFROG bug caused the retrieved field to be centered in time on each iteration. This is not necessary, and was fixed.
• Out Of Memory errors handled more gracefully.
• Closing the Raw Data window could result in an exception message: this was fixed.
• Error in calculating the XFROG frequency marginal calibration was fixed.
• Full spectrum noise subtraction had a small error in computing the spectrum to subtract.

• Fixed a bug in TADPOLE algorithm that that caused certain data sets to give incorrect answers (setting the cutoff to the right of center gave the same result for all positions).

• Fixed bug that caused the projections algorithm for DFG XFROG to stagnate.

• Added a readout of the current pixel value to the Raw Data form.
• Added the ablity to use a pulse with a flat phase as the guess for the succeeding iteration.

• Previously, the trace was centered in frequency using the peak of the zero-order frequency marginal. For traces that are double-peaked in frequency, this is inappropriate. The program now uses the first moment of the zero-order frequency marginal.

• Corrected a final small error in marginal calculations.

• Corrected a bug that led to error messages when using a custom size for the experimental raw data window.

• Corrected a bug that sometimes led to errors reading files with non-conventional line return characters.
• fixed some problems with the calculation of marginals in SHG FROG. If you have experience incorrect calculation of marginals, contact Femtosoft for a free upgraded copy of the program.

• Addition of XFROG capability! XFROG enables the measurement of a weak pulse using a well-characterized reference pulse at any wavelength (unlike TADPOLE, which requires spectral overlap).
• Added a button to force a strategy change. Useful for when a strategy is converging very slowly and you want to move on to the next one, rather than wait for it to stop naturally.

• Fixed data entry bug that could result in 1 part in 10,000 error in central wavelength for experimental data.

FROG 2

• New Shortcuts for projections added.

• Fixed a bug dealing with data extraction for experimental data (drawing the extraction rectangle the "wrong" way didn't work).

• TADPOLE algorithm for ultraweak pulses
• Calculation of the marginals
• Fully configurable FROG retrieval algorithm
• FROG keeps a history of each retrieval in a session, so that you can experiment with the parameters to get the lowest error retrieval for your data
• User selectable initial field

FROG 1

• Context sensitive help
• Extensive pulse generation facility
  • Uses real units (fs, nm)
  • Gaussian, sech, or super-Gaussian pulses
  • Double pulses in time or frequency domain
  • Self-phase modulation
  • Cubic temporal and spectral phase
  • Quadratic spectral phase
• Reads experimental calibrations from data file header
• Use previously generated electric fields read in from disk
• Resampling of the delay axis
• Graphical extraction of experimental data - leave your noise behind
• Real-time graph of FROG error versus iteration

• Retrieve pulses from experimental data
• Generate traces from your input pulse specifications
• Saves all data to disk:
  • Original FROG trace
  • Retrieved FROG trace
  • Original electric field (time and frequency domain, intensity and phase)
  • Retrieved electric field (time and frequency domain, intensity and phase)
  • Autocorrelations of original and retrieved fields
  • FROG trace marginals
  • Pulse diagnostics: FWHM (temporal and spectral), time-bandwidth products (FWHM, rms, Laplacian)
• Real-time graphic display: watch the algorithm converge in real time
• Automatically "grids" experimental data to FFT-compatible time and frequency spacings
• Perform noise subtraction and Fourier filtering on your data