Intense infrared lasers for strong-field science

Abstract

The advent of chirped-pulse amplification in the 1980s and femtosecond Ti:sapphire lasers in the 1990s enabled transformative advances in intense laser–matter interaction physics. Whereas most of experiments have been conducted in the limited near-infrared range of 0.8–1 μm, theories predict that many physical phenomena such as high harmonic generation in gases favor long laser wavelengths in terms of extending the high-energy cutoff. Significant progress has been made in developing few-cycle, carrier-envelope phase-stabilized, high-peak-power lasers in the 1.6–2 μm range that has laid the foundation for attosecond X ray sources in the water window. Even longer wavelength lasers are becoming available that are suitable to study light filamentation, high harmonic generation, and laser–plasma interaction in the relativistic regime. Long-wavelength lasers are suitable for sub-bandgap strong-field excitation of a wide range of solid materials, including semiconductors. In the strong-field limit, bulk crystals also produce high-order harmonics. In this review, we first introduce several important wavelength scaling laws in strong-field physics, then describe recent breakthroughs in short- (1.4–3 μm), mid- (3–8 μm), and long-wave (8–15 μm) infrared laser technology, and finally provide examples of strong-field applications of these novel lasers. Some of the broadband ultrafast infrared lasers will have profound effects on medicine, environmental protection, and national defense, because their wavelengths cover the water absorption band, the molecular fingerprint region, as well as the atmospheric infrared transparent window.

Efficient generation of femtosecond multi-mJ pulses at 3 µm

“…The output peak power can be further increased by broadening the spectrum through a noncollinear configuration and by changing the coating of the compressor. In addition to driving attosecond X-ray sources, the MIR OPCPA is a powerful tool to study light filamentation in the transmission window of air and other strong-field physics processes [6].…”

Modeling of sub-nanosecond Fe:ZnSe mid-IR gain-switched laser operating at room temperature

“…Most of the spectroscopic from Table 1 are well characterized and numerous spectroscopic characterizations were taken from reviews [1,5,11]. There are three parameters for which spectroscopic values are not well justified.…”

“…Many scientific and industrial applications (such as pump sources for optical parametric chirped-pulse amplification, highorder harmonic generation, polymer material processing, molecular spectroscopy, and biomedical applications) require a mid-IR laser with sub-ns pulse duration [1][2][3][4]. However, the number of effective laser sources operating in this temporal and spectral domain is limited.…”

Optical pumping for high-power ultrashort LWIR gas lasers

“…There is great interest in short-pulse, high peak power lasers at long-wave infrared (LWIR) wavelengths for various research fields including nonlinear optics, atomic, molecular and optical (AMO) physics, and intense laser-plasma interactions [1,2]. An existing technique is multi-staged nonlinear down-conversion from a near infrared (NIR), ultrashort solid-state laser, but the efficiency is extremely low, e.g., ~ 0.1% at 10 µm wavelength.…”