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Pump-probe phase spectroscopy with submilliradian sensitivity and nanosecond time delay using Michelson interferometers
Published
Author(s)
Chad Cruz, John C. Stephenson, Sebastian Engmann, Emily Bittle, Jared Wahlstrand
Abstract
We describe an experimental scheme for sensitive pump-probe spectral interferometry measurements at long time delays using two Michelson interferometers. It has practical advantages over the Sagnac interferometer method typically used when long time delays are required. First, with the Sagnac interferometer, achieving many nanosecond delays requires expanding the size of the interferometer so that the reference pulse arrives before the probe pulse. Because the two pulses still pass through the same region of the sample, long-lived effects can still affect the measurement. In our scheme, the probe and reference pulses are spatially separated at the sample. Second, a fixed delay between probe and reference pulses is typically produced by a birefringent plate for a Sagnac interferometer, while in our scheme it is straightforward to produce and is continuously adjustable while maintaining alignment. Two applications are demonstrated. First, transient phase spectra are presented in a thin tetracene film. Second, impulsive stimulated Raman measurements are presented in Bi$_3$Ge$_4$O$_12}$.
Cruz, C.
, Stephenson, J.
, Engmann, S.
, Bittle, E.
and Wahlstrand, J.
(2023),
Pump-probe phase spectroscopy with submilliradian sensitivity and nanosecond time delay using Michelson interferometers, Optics Express, [online], https://doi.org/10.1364/OE.483358, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=935662
(Accessed October 16, 2025)