Fig. 1. The first OPCPA. (a) Experimental setup. (b) Amplified spectrum. (c) Autocorrelation function of compressed pulse. Image at the bottom shows one of the authors (AD) aligning picosecond Nd:glass laser, which was used for driving the OPCPA experiment. Figure reproduced with permission from: (a–c) ref.³, Elsevier.

Fig. 2. State of the art of few optical cycle table-top OPCPA systems.The central wavelength is indicated by colored circles, where color coding denotes the nonlinear crystal used as an amplifying medium. The amplified bandwidths are schematically depicted by horizontal bars, which represent the full width of the amplified spectrum. The time bar on the top marks the year of experimental inception of OPCPA in the particular wavelength region.

Fig. 3. (a) Layout of multi-terawatt high average power NIR OPCPA system with complex Yb:KGW laser-based front-end, which includes supercontinuum generation, DFG and complimentary noncollinear OPA. (b) Compressed pulse envelope measured with a self-referenced spectral interferometry (SRSI) and theoretical transform-limited pulse envelope (TL). (c) Comparison of seed and amplified pulse spectra. Photo at the bottom: laboratory view of a running system. Image courtesy dr. A. Varanavičius, Laser Research Center, Vilnius University. Figure reproduced with permission from: (a–c) ref.⁸⁸, The Optical Society.

Fig. 4. Graphical summary of the performance of multi-millijoule >100-GW and TW-class table-top OPCPA systems in the NIR (yellow area), SWIR (blue area) and MIR (magenta area). Color coding of the data points denotes the gain medium of pump laser, which is indicated in the legend.

Fig. 5. Graphical summary of the performance of high average power NIR OPCPA systems. Color coding of data points denotes the gain medium of pump laser, while different shapes indicate the configuration of laser amplifier.

Fig. 6. Graphical summary of the performance of high average power SWIR OPCPA systems. Color coding of data points denotes the gain medium of pump laser, while different shapes indicate the configuration of laser amplifier.

Fig. 7. Graphical summary of the performance of high average power MIR OPCPA systems. Color coding of data points denotes the gain medium of pump laser, while different shapes indicate the configuration of laser amplifier.

Fig. 8. Layout of the 3.9 μm OPCPA system. Photo at the bottom: image of the back-end of the system. Image courtesy dr. A. Pugžlys, Photonics Institute, Technical University Wien. Figure reproduced with permission from ref.¹⁷⁵, under a Creative Commons Attribution 4.0 International License.

Fig. 9. (a) Setup of the MIR OPCPA that comprises the front-end including femtosecond Cr:ZnS master oscillator and fluoride fiber (ZBLAN), Ho:YLF regenerative amplifier as pump and two optical parametric amplification stages based on ZGP crystals. (b) Spectral intensities of the signal (left) and the corresponding idler pulses (right). Autocorrelation functions (ACF) of (c) uncompressed signal at 2.99 μm and (d) re-compressed idler pulses at 5.4 μm. Figure reproduced with permission from ref.¹⁸², The Optical Society.

Fig. 10. (a) Schematic illustration of the coherent kilo-electronvolt X-ray supercontinua emitted when a MIR laser pulse is focused into a high-pressure He gas-filled waveguide, where phase-matched harmonic signal grows quadratically with pressure. (b) Experimental HHG spectra emitted under full phase-matching conditions as a function of driving wavelength (yellow: 0.8 μm; green: 1.3 μm; blue: 2 μm; purple: 3.9 μm). Inset: Fourier transform-limited pulse duration of 2.5 as. Figure reproduced with permission from ref.²²³, AAAS.

Fig. 11. (a) Spectrum of the millimeter-wave-to-ultraviolet supercontinuum. (b) Electro-optic sampling and (c) autocorrelation traces of the waveforms of the THz-millimeter-wave field. (d) The millimeter-wave-to-THz part of the supercontinuum spectrum. Figure reproduced with permission from ref.²⁶¹, The Optical Society.