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Abstract A new optical delivery system has been developed for the (scanning) transmission electron microscope. Here we describe the in situ and “rapid ex situ ” photothermal heating modality of the system, which delivers >200 mW of optical power from a fiber-coupled laser diode to a 3.7 μ m radius spot on the sample. Selected thermal pathways can be accessed via judicious choices of the laser power, pulse width, number of pulses, and radial position. The long optical working distance mitigates any charging artifacts and tremendous thermal stability is observed in both pulsed and continuous wave conditions, notably, no drift correction is applied in any experiment. To demonstrate the optical delivery system’s capability, we explore the recrystallization, grain growth, phase separation, and solid state dewetting of a Ag 0.5 Ni 0.5 film. Finally, we demonstrate that the structural and chemical aspects of the resulting dewetted films was assessed.
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This content will become publicly available on December 1, 2025
Cutting speed and behaviors of ice using Yb-doped fiber laser
The use of a laser to cut or drill ice has been proposed and demonstrated multiple times in previous decades as a novel, but never adopted, machining tool in glaciology and paleoclimate studies. However, with the rapid development of high power fiber-laser technology over the past few decades, it is timely to perform further studies using this new tool. An investigation is made herein on the cutting of ice using a Yb-doped fiber laser emitting at a wavelength of 1070 nm, the most extensively developed and highest power fiber laser technology, in pulsed and continuous-wave operation. Visible-light observations of clear tap water ice samples, moving at a constant velocity relative to a pulsed laser beam, demonstrate a linear relationship between the duration of a millisecond-range laser pulse and the depth of the meltwater-free cut formed in response. Thermal imaging of the irradiated face shows that peripheral heating trends linearly for pulse lengths greater than 5 ms. A comparison of pulse trains with a constant time-averaged power suggests that shorter pulses are advantageous in slot-cutting efficiency and in minimizing visible alterations in the surrounding ice. These results demonstrate the viability of powerful fiber-compatible lasers as a tool for ice sample retrieval and processing.
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- Award ID(s):
- 2032463
- PAR ID:
- 10554583
- Publisher / Repository:
- Elsevier B.V.
- Date Published:
- Journal Name:
- Cold Regions Science and Technology
- Volume:
- 228
- Issue:
- C
- ISSN:
- 0165-232X
- Page Range / eLocation ID:
- 104335
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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