New technique measures ultrashort laser pulses at focus

Georgia Tech physics professor Rick Trebino and graduate student Pam Bowlan test their system that measures instrumentation aberrations and allows researchers to create desired distortion-free pulses at the focus. Click here for more information.

Lasers that emit ultrashort pulses of light are used for numerous applications including micromachining, microscopy, laser eye surgery, spectroscopy and controlling chemical reactions. But the quality of the results is limited by distortions caused by lenses and other optical components that are part of the experimental instrumentation.

To better understand the distortions, researchers at the Georgia Institute of Technology developed the first device to directly measure complex ultrashort light pulses in space and time at and near the focus. Measuring the pulse at the focus is important because that’s where the beam is most intense and where researchers typically utilize it. Knowing how the light is distorted allows researchers to correct for the aberrations by changing a lens or using a pulse shaper or compressor to manipulate the pulse into the desired form.

Georgia Tech physics professor Rick Trebino and graduate student Pam Bowlan make slight adjustments to the device they developed that directly measures complex ultrashort light pulses in space and time... Click here for more information.

“Researchers have always measured the pulse immediately as it exited the laser, so they didn’t realize the extent to which the pulse became distorted by the time it reached the focus after traveling through the optics and lenses in the system,” said Rick Trebino, a professor in the Georgia Institute of Technology’s School of Physics and Georgia Research Alliance Eminent Scholar in Ultrafast Optical Physics.