Sample exchange by beam scanning with applications to noncollinear pump-probe spectroscopy at kilohertz repetition rates
(2017) In Review of Scientific Instruments 88(6).- Abstract
In laser spectroscopy, high photon flux can perturb the sample away from thermal equilibrium, altering its spectroscopic properties. Here, we describe an optical beam scanning apparatus that minimizes repetitive sample excitation while providing shot-to-shot sample exchange for samples such as cryostats, films, and air-tight cuvettes. In this apparatus, the beam crossing point is moved within the focal plane inside the sample by scanning both tilt angles of a flat mirror. A space-filling spiral scan pattern was designed that efficiently utilizes the sample area and mirror scanning bandwidth. Scanning beams along a spiral path is shown to increase the average number of laser shots that can be sampled before a spot on the sample cell is... (More)
In laser spectroscopy, high photon flux can perturb the sample away from thermal equilibrium, altering its spectroscopic properties. Here, we describe an optical beam scanning apparatus that minimizes repetitive sample excitation while providing shot-to-shot sample exchange for samples such as cryostats, films, and air-tight cuvettes. In this apparatus, the beam crossing point is moved within the focal plane inside the sample by scanning both tilt angles of a flat mirror. A space-filling spiral scan pattern was designed that efficiently utilizes the sample area and mirror scanning bandwidth. Scanning beams along a spiral path is shown to increase the average number of laser shots that can be sampled before a spot on the sample cell is resampled by the laser to ∼1700 (out of the maximum possible 2500 for the sample area and laser spot size) while ensuring minimal shot-to-shot spatial overlap. Both an all-refractive version and an all-reflective version of the apparatus are demonstrated. The beam scanning apparatus does not measurably alter the time delay (less than the 0.4 fs measurement uncertainty), the laser focal spot size (less than the 2 μm measurement uncertainty), or the beam overlap (less than the 3.3% measurement uncertainty), leading to pump-probe and autocorrelation signal transients that accurately characterize the equilibrium sample.
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- author
- Spencer, Austin P. ; Hill, Robert J. ; Peters, William K. ; Baranov, Dmitry LU ; Cho, Byungmoon ; Huerta-Viga, Adriana ; Carollo, Alexa R. LU ; Curtis, Anna C. and Jonas, David M.
- publishing date
- 2017-06-01
- type
- Contribution to journal
- publication status
- published
- in
- Review of Scientific Instruments
- volume
- 88
- issue
- 6
- article number
- 064101
- pages
- 7 pages
- publisher
- American Institute of Physics (AIP)
- external identifiers
-
- pmid:28667957
- scopus:85021438456
- ISSN
- 0034-6748
- DOI
- 10.1063/1.4986628
- language
- English
- LU publication?
- no
- additional info
- Publisher Copyright: © 2017 Author(s).
- id
- 5c8ddd1e-1cf6-4e9a-a210-03fd19d6d4ab
- date added to LUP
- 2023-01-17 13:54:00
- date last changed
- 2024-03-06 07:10:52
@article{5c8ddd1e-1cf6-4e9a-a210-03fd19d6d4ab, abstract = {{<p>In laser spectroscopy, high photon flux can perturb the sample away from thermal equilibrium, altering its spectroscopic properties. Here, we describe an optical beam scanning apparatus that minimizes repetitive sample excitation while providing shot-to-shot sample exchange for samples such as cryostats, films, and air-tight cuvettes. In this apparatus, the beam crossing point is moved within the focal plane inside the sample by scanning both tilt angles of a flat mirror. A space-filling spiral scan pattern was designed that efficiently utilizes the sample area and mirror scanning bandwidth. Scanning beams along a spiral path is shown to increase the average number of laser shots that can be sampled before a spot on the sample cell is resampled by the laser to ∼1700 (out of the maximum possible 2500 for the sample area and laser spot size) while ensuring minimal shot-to-shot spatial overlap. Both an all-refractive version and an all-reflective version of the apparatus are demonstrated. The beam scanning apparatus does not measurably alter the time delay (less than the 0.4 fs measurement uncertainty), the laser focal spot size (less than the 2 μm measurement uncertainty), or the beam overlap (less than the 3.3% measurement uncertainty), leading to pump-probe and autocorrelation signal transients that accurately characterize the equilibrium sample.</p>}}, author = {{Spencer, Austin P. and Hill, Robert J. and Peters, William K. and Baranov, Dmitry and Cho, Byungmoon and Huerta-Viga, Adriana and Carollo, Alexa R. and Curtis, Anna C. and Jonas, David M.}}, issn = {{0034-6748}}, language = {{eng}}, month = {{06}}, number = {{6}}, publisher = {{American Institute of Physics (AIP)}}, series = {{Review of Scientific Instruments}}, title = {{Sample exchange by beam scanning with applications to noncollinear pump-probe spectroscopy at kilohertz repetition rates}}, url = {{http://dx.doi.org/10.1063/1.4986628}}, doi = {{10.1063/1.4986628}}, volume = {{88}}, year = {{2017}}, }