● Autocorrelator for femtosecond laser

Thorlabs' FSAC Interferometric Autocorrelator provides approximate pulse width measurements in the 650 - 1100 nm wavelength range. Well suited for diagnostics of femtosecond Ti:Sapphire lasers, it consists primarily of a modified Michelson interferometer with a nonlinear detector at the output.

A BNC connector outputs the autocorrelation signal, which can be viewed on any oscilloscope with >1.5 MHz bandwidth. An example of the direct output from the FSAC is shown in the graph to the right. A photodiode amplifier with selectable gain from 0 dB to 70 dB provides compatibility with a large range of optical input powers, up to a maximum average power of 150 mW.

Intuitive, easy-to-reach controls on the outside of the enclosure allow the user to optimize the resolution and fringe contrast. The controls for the delay arm enable a full scan range of 50 fs to 10 ps (i.e., ±25 fs to ±5 ps), and a micrometer tunes the detector's position for maximum signal. Detailed usage recommendations and examples are available in the manual.