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We demonstrate spectral broadening and compression of amplified pulses from a titanium sapphire laser system using an argon-filled stretched, hollow-core fiber and an acousto-optic modulator based pulse-shaper. We characterize the pulses using pulse-shaper assisted collinear frequency resolved optical gating, pulse-shaper assisted D-scans, and D-scans using a variable path length water cell. The different compression and characterization approaches consistently compress the pulses down to < 6 fs, less than ∼1 fs from the transform limit. We discuss prospects for pulse shape spectroscopy with these broadband pulses, given our control over the spectral amplitude and phase.
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Optimizing EPR pulses for broadband excitation and refocusing
In this paper, we numerically optimize broadband pulse shapes that maximize Hahn echo amplitudes. Pulses are parameterized as neural networks (NN), nonlinear amplitude limited Fourier series (FS), and discrete time series (DT). These are compared to an optimized choice of the conventional hyperbolic secant (HS) pulse shape. A power constraint is included, as are realistic shape distortions due to power amplifier nonlinearity and the transfer function of the microwave resonator. We find that the NN, FS, and DT parameterizations perform equivalently, offer improvements over the best HS pulses, and contain a large number of equivalent optimal maxima, implying the flexibility to include further constraints or optimization goals in future designs.
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- Award ID(s):
- 2154302
- PAR ID:
- 10585015
- Publisher / Repository:
- Elsevier
- Date Published:
- Journal Name:
- Journal of Magnetic Resonance
- Volume:
- 369
- Issue:
- C
- ISSN:
- 1090-7807
- Page Range / eLocation ID:
- 107807
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1016/j.jmr.2024.107807
