MOSAIC Modified-Spectrum Auto Interferometric Correlation

MOSAIC is an algorithm that will transform an interferometric autocorrelation (IAC) trace of an ultrashort laser pulse into a trace whose shape is far more sensitive to chirp than IAC.

In rapid-scan autocorrelators, MOSAIC can be used to monitor and hence minimize the chirp (if desired) in real time. The only hardware required (in addition to the autocorrelator) is a digital oscilloscope displaying interferometric autocorrelation (IAC) waveforms interfaced to a computer equipped with the MOSAIC program. By spectral filtering the IAC, the resulting MOSAIC trace displays features highly sensitive to chirp. This work was published in Optics Letters.

See also OptiLet-06-122-MOSAIC.pdf and OptiLetR-MOSAIC-Final-07.pdf

The figure shows experimental (a) IAC and (b) MOSAIC waveforms for a nearly chirp-free pulse from a mode-locked Ti:sapphire laser. The lower panels depict IAC (c) and corresponding MOSAIC (d) waveforms for a pulse with more chirp. Note that the IAC waveforms (a) and (c) appear to be identical. The MOSAIC signal, however, clearly reveals greater chirp (compare b to d) due to the enhanced shoulders.

We have currently three separate MOSAIC LabVIEW packages available for free download on this website. Each package contains a short manual and a virtual instrument (VI) designed for a specific oscilloscope series: Tektronix TDS500, TDS1000/2000, and TDS3000. The MOSAIC VI can also analyze saved IAC waveforms from text or data files. If your digital oscilloscope is not listed above, we encourage you to contact us and we will customize a MOSAIC package for your application.

Contacts: Daniel Bender

  1. M. Sheik-Bahae, Opt. Lett. 22, 399 (1997)
  2. T. Hirayama and M. Sheik-Bahae, "Real-time chirp diagnostic for ultrashort laser pulses", Opt. Lett., 27, 860 (2002)



  • Single shot measurement
  • Spectral Phase Retrieval


*Note: Requires MATLAB

Version 1.6  can be used with

  • Tektronix TDS 500 series
  • Tektronix TDS 1000 series
  • Tektronix TDS 2000 series
  • Tektronix TDS 3000 series
  • National Instruments PCI 5122 scope card