Broadband mid-infrared coverage (2–17  μm) with few-cycle pulses via cascaded parametric processes

Intra-pulse difference-frequency generation of mid-infrared (27–20 μm) by random quasi-phase-matching

“…2(b), the spectrum spans nearly three octaves and covers the wavelength range from 2.7 to 20 μm (at −30 dB)-a bandwidth that can support few-cycle pulses in the MIR. Interestingly, a cascaded intra-pulse difference-frequency process is also found under the RQPM condition [15,16].…”

“…This wavelength range can be covered by numerous different schemes, each with their own strengths and weaknesses in terms of complexity, simultaneous bandwidth, power, efficiency, and pulse durations [3][4][5][6][7][8]. Yet, the most popular method of coherent broadband MIR generation remains nonlinear downconversion from the nearinfrared-a spectral region where many high-power driving lasers are available [4,7,[9][10][11][12][13][14][15][16][17][18]. Obviously, this process requires a suitable nonlinear medium that is transparent for the pump, signal, and idler wavelengths.…”

Multi-octave-spanning supercontinuum generation through high-energy laser filaments in YAG and ZnSe pumped by a 2.4 μm femtosecond Cr:ZnSe laser

“…Despite the recent development of all-solid-state mid-IR laser sources, it is still in early stages of combining the advanced mid-IR lasers and strong-field nonlinear optics. So far, only a handful of reports discuss SCG and other nonlinear optics in bulk crystals pumped by advanced mid-IR solid-state lasers [16][17][18] .…”

Phase-only pulse shaper for multi-octave light sources

“…The phase relationship between optical components plays a crucial role in controlling the electric field of broadband transient optical radiations [1] and a large number of devices have been proposed to shape the spectral phase: bulk media, prism, grating and grism pairs [2,3], acousto-optic dispersive programmable filters (AOPDFs) [4], zero-dispersion lines [5], dispersive mirrors [6]. The growing development of light sources delivering pulses as short as a few optical cycles [7][8][9][10][11][12], either based on nonlinear post-compression or parametric amplification, has triggered the development of innovative pulse shaping or pulse compression devices, capable of handling bandwidths spanning over multiple optical octaves. Such spectral widths raise specific challenges: maximal spectral acceptance, minimal internal dispersion, high throughput are mandatory properties which tend to rule out most of the aforementioned techniques with the exception of thin wedges, thin plates and dispersive mirrors.…”