We propose a new architecture, double-pass multiple-plate continuum (DPMPC), for nonlinear pulse compression. In addition to smaller footprint, a double-pass configuration is designed to achieve substantial bandwidth broadening without incurring noticeable higher-order dispersion, thus improving the temporal contrast over those of traditional single-pass geometry when only quadratic spectral phase can be compensated. In our proof-of-concept experiment, 187~$μ$J, 190-fs Yb-based laser pulse is compressed to 20~fs with high throughput (75%), high Strehl ratio (0.76) and excellent beam homogeneity by using DPMPC. Subsequently generated octave-spanning spectrum exhibits a significantly raised blue tail compared with that driven by pulses from a single-pass counterpart.
Few-cycle pulses present an essential tool to track ultrafast dynamics in matter and drive strong field effects. To address photon-hungry applications, high average power lasers are used which, however, cannot directly provide sub-100 fs pulse durations. Post-compression of laser pulses by spectral broadening and dispersion compensation is the most efficient method to overcome this limitation. Here, we demonstrate a notably compact setup which turns a 0.1 GW peak power, picosecond laser into a 2.9 GW peak power, 8.2 fs source. The 120-fold pulse duration shortening is accomplished in a two-sta…
We demonstrate theoretically that few-cycle vortex beam with subterawatt peak power can be generated by self-compression of mid-infrared femtosecond vortex beam using the thin-plate scheme. The 3 μm femtosecond vortex beam with input duration of 90 fs is compressed to 15.1 fs with the vortex characteristics preserved. The conversion efficiency is as high as 91.5% and the peak power reaches 0.18 TW. The generation of the high-peak-power few-cycle vortex beam is owing to the proper spatiotemporal match by this novel scheme, where the spectrum is broadened enough, the negative group velocity disp…
As Ultrafast laser technology advances towards ever higher peak and average powers, generating sub-50 fs pulses from laser architectures that exhibit best power-scaling capabilities remains a major challenge. Here, we present a very compact and highly robust method to compress 1.24 ps pulses to 39 fs by means of only a single spectral broadening stage which neither requires vacuum parts nor custom-made optics. Our approach is based on the hybridization of the multi-plate continuum and the multi-pass cell spectral broadening techniques. Their combination leads to significantly higher spectral b…
We demonstrate the electromagnetic performance of waveguides for femtosecond electron beam bunch manipulation and compression with strong-field terahertz (THz) pulses. The compressor structure is a dispersion-free exponentially-tapered parallel-plate waveguide (PPWG) that can focus single-cycle THz pulses along one dimension. We show test results of the tapered PPWG structure using electro-optic sampling (EOS) at the interaction region with peak fields of at least 300 kV/cm given 0.9 uJ of incoming THz energy. We also present a modified shorted design of the tapered PPWG for better beam manipu…
We demonstrate the reliable generation of 1-mJ, 31-fs pulses with an average power of 1 kW by post-compression of 200-fs pulses from a coherently combined Yb:fiber laser system in an argon-filled Herriott-type multi-pass cell with an overall compression efficiency of 96%. We also analyze the output beam, revealing essentially no spatio-spectral couplings or beam quality loss.
The output of a 200 kHz, 34 W, 300 fs Yb amplifier is compressed to 31 fs with > 88 % efficiency to reach a peak power of 2.5 GW, which to date is a record for a single-stage bulk multi-pass cell. Despite operation 80 times above the critical power for self-focusing in bulk material, the setup demonstrates excellent preservation of the input beam quality. Extensive beam and pulse characterizations are performed to show that the compressed pulses are promising drivers for high harmonic generation and nonlinear optics in gases or solids.
We demonstrate an efficient hybrid-scheme for nonlinear pulse compression of high-power thin-disk oscillator pulses to the sub-10 fs regime. The output of a home-built, 16 MHz, 84 W, 220 fs Yb:YAG thin-disk oscillator at 1030 nm is first compressed to 17 fs in two nonlinear multipass cells. In a third stage, based on multiple thin sapphire plates, further compression to 8.5 fs with 55 W output power and an overall optical efficiency of 65% is achieved. By sending the 2.5-cycle pulses into a lithium iodate crystal, we were able to generate ultra-broadband mid-infrared pulses covering the spectr…
In this work, we demonstrate post-compression of 1.2 picosecond laser pulses to 13 fs via gas-based multi-pass spectral broadening. Our results yield a single-stage compression factor of about 40 at 200 W in-burst average power and a total compression factor >90 at reduced power. The employed scheme represents a route towards compact few-cycle sources driven by industrial-grade Yb:YAG lasers at high average power.
A single photon can be made to entangle simultaneously in its different internal degrees of freedom (DoF) -- polarization, orbital angular momentum (OAM), and frequency -- as well as in its external DoF -- path. Such entanglement in multiple DoF is known as hyperentanglement and provide additional advantage for quantum information processing. We propose a passive optical setup using $q$-plates and polarization beamsplitters to hyperentangle an incoming single photon in polarization, OAM, and path DoF. By mapping polarization DoF to a two-dimensional coin state, and path and OAM DoF to two spat…
