Femtosecond petawatt (fs-PW) ultraintense lasers, which are produced by chirped-pulse amplification, have opened and accelerated the research and development of plasma physics, particle physics, astrophysics, nuclear physics, etc., in the past two decades. The Ti: sapphire crystal, as a broadband laser material, can support a high-energy short pulse.
The upper limit for titanium sapphire ultra-intense ultrashort lasers is currently 10-petawatt. Researchers typically shift from titanium: sapphire pulse amplification technology to optical parametric pulse amplification technology, which utilizes deuterated potassium dihydrogen phosphate nonlinear crystals for further development beyond this range. This transition is part of the planning process for developing lasers with power levels ranging from 10-petawatt to 100-petawatt.
The amplification of lasers using larger titanium sapphire crystals is hindered by strong transverse parasitic lasing. This issue becomes more pronounced as the size of the titanium sapphire crystals increases, making laser amplification challenging.
Researchers have implemented a novel approach to overcome the limitations posed by transverse parasitic lasing and extend the capabilities of titanium: sapphire ultra-intense ultrashort lasers beyond the 10-petawatt limit. This involves coherently tiling multiple titanium sapphire crystals together.
Doing so increases the aperture diameter of the entire tiled titanium sapphire crystal and simultaneously limits the transverse parasitic lasing within each tiling crystal. This breakthrough allows for more effective laser amplification and paves the way for developments in the 10-petawatt to 100-petawatt range.
Corresponding author Yuxin Leng of the Shanghai Institute of Optics and Fine Mechanics notes, “The tiled titanium: sapphire laser amplification was successfully demonstrated in our 100-terawatt (i.e., 0.1-petawatt) laser system. We achieved near-ideal laser amplification using this technology, including high conversion efficiencies, stable energies, broadband spectra, short pulses, and small focal spots.”
“Coherently tiled titanium: sapphire laser amplification provides a relatively easy and inexpensive way to surpass the current 10-petawatt limit. By adding a 2×2 coherently tiled titanium:sapphire high-energy laser amplifier in China’s SULF or EU’s ELI-NP, the current 10-petawatt can be further increased to 40-petawatt, and the focused peak intensity can be increased by nearly 10 times or more.”
Journal Reference:
- Yanqi Liu, Keyang Liu, Zhaoyang Li, Yuxin Leng, Ruxin Li. Coherently tiled Ti:sapphire laser amplification: a way to break the 10 petawatt limit on current ultraintense lasers. Advanced Photonics Nexus. DOI: 10.1117/1.APN.2.6.066009