Abstract
We present a new method for the measurement of the stimulated Raman spectrum based on time-dependent spatial modulation of a laser beam as it passes through a Raman active medium. This effect is similar to the instantaneous Kerr lensing and Kerr deflection yet involves resonant vibrations which result in a time-dependent refractive index change. We use sub-nanojoule pulses together with a sensitive pump-probe measurement apparatus to excite and detect the fine (10-5-10-4) temporal and spatial variations in intensity resulting from the Raman-induced Kerr effect. We demonstrate the effect by changing the spatial overlap between the pump and probe at the sample and measuring the time-dependent deformation of the probe beam's cross section. This method is particularly useful for detection of low-frequency Raman lines, as we demonstrate by measuring the Raman spectrum of neat liquids in a cuvette.
Original language | English |
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Article number | 092501 |
Journal | APL Photonics |
Volume | 3 |
Issue number | 9 |
DOIs | |
Publication status | Published - Sep 2018 |
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Computer Networks and Communications