High power IR-OPA

- Based on Ti:Sa laser pump sources

- 5 cycle pulses, 10 mJ, 1.8 µm wavelength 

FIG. 1. Experimental setup for the generation of higher peak power IR Pulses; BS: Beam splitter, DM: Dichroic mirror, Pol: Polarizer, ϕ: Pinhole diameter used for spatial filtering, Autocorrelator: Home build all reflective second harmonic generation correlator, λI: Central wavelength of the Idler, λS: Central wavelength of the Signal.

FIG. 2. Pulse characterization. In (a): the spectrum of the unamplified OPA Idler in red and the spectrum of the amplified Idler (1.8 µm) in black. In (b): the autocorrelation trace of the OPA output in red and the amplified IR pulses (1.8 µm) in black. The dotted-dashed curves in red and in black are Gaussian fit of the autocorrelation trace of the OPA Idler and the amplified Idler, respectively.

FIG. (1) and (2) according to “10 mJ 5-cycle pulses at 1.8 µm through optical parametric amplification”, N. Thiré, S. Beaulieu, V. Cardin, A. Laramée, V. Wanie, B. E. Schmidt, F. Légaré, Appl. Phys. Lett. 106, 091110 (2015).

High power few-cycle IR pulses for ATTO-Science

- Based on Ti:Sa laser pump sources

- 2 cycle pulses, 5 mJ, 1.8 µm wavelength 

FIG.3. Illustration of the experimental setup for the generation of high intensity few-cycle mid-infrared pulses. The top area depicts the HE-OPA of the Advanced Laser Light Source. The stretched hollow-core fiber length is 3 m with 1 mm inner diameter. Depicted telescope effective focal length is 3.8 m with an 1/e2 beam waist of 750 µm diameter. Front vacuum chamber and exit gas inlet chamber are enclosed by 2 mm CaF2 windows. (DM: various dichroic mirrors (as shown); Pol: Polarizer; BS: Beam splitter; LEC/HEC: Low/High Energy grating compressors; TOPAS: commercial OPA; SF: Spatial filter pinhole; SHG-Corr: all-reflective second harmonic auto-correlator).

FIG.4. Characterization of the fiber input and output pulses. (a) Spectrum of the multi-cycle input pulse in red compared with the broad spectrum at a pressure 300 mTorr at the exit side in shaded blue. Inset: CCD images of the input pulse focal spot (up) and of the output pulse collimated at 2 m after the fiber. (b) Autocorrelation trace of the multi-cycle input pulse in red and of the compressed 2-cycle pulse. Dotted lines denote a Gaussian fit.

FIG. (3) and (4) according to "0.42 TW 2-cycle pulses at 1.8 µm via hollow-core fiber compression”, V. Cardin, N. Thiré, S. Beaulieu, V. Wanie, F. Légaré, B. E. Schmidt, Appl. Phys. Lett. 107, 181101 (2015).