Abstract With the invention of chirped pulse amplification for lasers in the mid-1980s, high power ultrafast lasers entered into the world as a disruptive tool, with potential impact on a broad range of application areas. Since then, ultrafast lasers have revolutionized laser–matter interaction and unleashed their potential applications in manufacturing processes. With unprecedented short pulse duration and high laser intensity, focused optical energy can be delivered to precisely define material locations on a time scale much faster than thermal diffusion to the surrounding area. This unique characteristic has fundamentally changed the way laser interacts with matter and enabled numerous manufacturing innovations over the past few decades. In this paper, an overview of ultrafast laser technology with an emphasis on femtosecond laser is provided first, including its development, type, working principle, and characteristics. Then, ultrafast laser applications in manufacturing processes are reviewed, with a focus on micro/nanomachining, surface structuring, thin film scribing, machining in bulk of materials, additive manufacturing, bio manufacturing, super high resolution machining, and numerical simulation. Both fundamental studies and process development are covered in this review. Insights gained on ultrafast laser interaction with matter through both theoretical and numerical researches are summarized. Manufacturing process innovations targeting various application areas are described. Industrial applications of ultrafast laser-based manufacturing processes are illustrated. Finally, future research directions in ultrafast laser-based manufacturing processes are discussed.
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Ultrafast Pulse Generation from Quantum Cascade Lasers
Quantum cascade lasers (QCLs) have broken the spectral barriers of semiconductor lasers and enabled a range of applications in the mid-infrared (MIR) and terahertz (THz) regimes. However, until recently, generating ultrashort and intense pulses from QCLs has been difficult. This would be useful to study ultrafast processes in MIR and THz using the targeted wavelength-by-design properties of QCLs. Since the first demonstration in 2009, mode-locking of QCLs has undergone considerable development in the past decade, which includes revealing the underlying mechanism of pulse formation, the development of an ultrafast THz detection technique, and the invention of novel pulse compression technology, etc. Here, we review the history and recent progress of ultrafast pulse generation from QCLs in both the THz and MIR regimes.
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- Award ID(s):
- 2149908
- NSF-PAR ID:
- 10394188
- Date Published:
- Journal Name:
- Micromachines
- Volume:
- 13
- Issue:
- 12
- ISSN:
- 2072-666X
- Page Range / eLocation ID:
- 2063
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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The development of new modes at x-ray free electron lasers has inspired novel methods for studying fluctuations at different energies and timescales. For closely spaced x-ray pulses that can be varied on ultrafast time scales, we have constructed a pair of advanced instruments to conduct studies targeting quantum materials. We first describe a prototype instrument built to test the proof-of-principle of resonant magnetic scattering using ultrafast pulse pairs. This is followed by a description of a new endstation, the so-called fluctuation–dissipation measurement instrument, which was used to carry out studies with a fast area detector. In addition, we describe various types of diagnostics for single-shot contrast measurements, which can be used to normalize data on a pulse-by-pulse basis and calibrate pulse amplitude ratios, both of which are important for the study of fluctuations in materials. Furthermore, we present some new results using the instrument that demonstrates access to higher momentum resolution.more » « less
- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.3390/mi13122063
