Multi-pass cells for post-compression of ultrashort laser pulses

Abstract

Ultrafast lasers reaching extremely high powers within short fractions of time enable a plethora of applications. They grant advanced material processing capabilities, are effective drivers for secondary photon and particle sources, and reveal extreme light-matter interactions. They also supply platforms for compact accelerator technologies, with great application prospects for tumor therapy or medical diagnostics. Many of these scientific cases benefit from sources with higher average and peak powers. Following mode-locked dye and titanium-doped sapphire lasers, broadband optical parametric amplifiers have emerged as high peak- and average power ultrashort pulse lasers. A much more power-efficient alternative is provided by direct post-compression of high-power diode-pumped ytterbium lasers—a route that advanced to another level with the invention of a novel spectral broadening approach, the multi-pass cell technique. The method has enabled benchmark results yielding sub-50-fs pules at average powers exceeding 1 kW, has facilitated femtosecond post-compression at pulse energies above 100 mJ with large compression ratios, and supports picosecond to few-cycle pulses with compact setups. The striking progress of the technique in the past five years puts light sources with tens to hundreds of TW peak and multiple kW of average power in sight—an entirely new parameter regime for ultrafast lasers. In this review, we introduce the underlying concepts and give brief guidelines for multi-pass cell design and implementation. We then present an overview of the achieved performances with both bulk and gas-filled multi-pass cells. Moreover, we discuss prospective advances enabled by this method, in particular including opportunities for applications demanding ultrahigh peak-power, high repetition rate lasers such as plasma accelerators and laser-driven extreme ultraviolet sources.

Divided-pulse nonlinear compression in a multipass cell

“…The setup based on pairs of 2 mm and 4 mm thick α-BBO crystal plates is cheap, ultra-compact and completely passively stable. In addition to gas-filled MPCs as presented in this work, DPNLC is expected to allow similar scaling potential for other polarization insensitive MPC schemes as well, including those based on anti-reflective coated bulk nonlinear media [9]. Thus, DPNLC is an extremely powerful extension to easily scale the performance of pre-built MPC-based nonlinear compression stages without requiring a complete rebuilding and, when designing an MPC from scratch, it allows significant reduction of cost and size of the setup.…”

“…The needed parameters are usually generated by a high-power amplifier scheme based on thin-disk, slab or fiber, followed by a nonlinear pulse compression stage to access the sub-100 fs regime [1,4,5]. While different post-compression schemes have been developed over the past decades, recently multipass cell (MPC) based approaches have gained a lot of attention [6][7][8][9]. Typically, MPCs feature a high transmission and are mostly resistant to pointing instabilities of the driving laser, allowing reliable nonlinear compression of kilowatt level average powers [5] and multi-millijoule pulse energies [4].…”

Linear collider based on laser-plasma accelerators

“…Over the long term, the development of reliable, high-rep-rate sources in the mid-wave infrared (3-8µm) and long-wave infrared (8-15 µm) could also provide unique opportunities for HEP applications, including as an enabling technology for an "all-optical" source of highbrightness, potentially spin-polarized, electron beams using two-color injection [42,43,64]. Other promising paths include using diode-pumped, cryogenically-cooled, thin-disk Yb:YAG or Tm:YLF as amplifier gain media [65][66][67][68], combined with nonlinear pulse compression technologies [69,70], or novel, plasma-based methods for modulating ps-duration pulses [71]. All candidate laser technologies require development of active control techniques for laser precision and stability [72,73], and high peak and average power handling optics, including compression gratings [74,75] and robust optical coatings [76][77][78].…”

High power, high repetition rate laser-based sources for attosecond science

“…Shortly after, Daniault et al demonstrated the compression of 30 fs, 1 mJ pulses from a Ti:Sapphire CPA down to 5.2 fs [106], extending implementation of MPC compression of Ti:Sapphire CPAs to the mJ energy range. A recent review about nonlinear pulse compression in MPCs can be found in [107].…”