Grebing et al. 2020: 1 mJ, 200 fs, Ar 700 mbar, 26 passes

1 mJ, 200 fs, Ar 700 mbar, 26 passes (Grebing et al., Opt. Lett. 45, 6250, 2020)

Paper and model

From the docstring of the script: what the paper describes, what the simulation uses, and what it leaves out.

Benchmark: 1 mJ, 200 fs, argon-filled Herriott cell (lens-frame solver).

C. Grebing, M. Müller, J. Buldt, H. Stark, J. Limpert, "Kilowatt-average-power compression of
millijoule pulses in a gas-filled multi-pass cell", Opt. Lett. 45, 6250 (2020),
doi:10.1364/OL.408998 (open access: arXiv:2103.00893).

Clean, textbook SPM stage in the mJ range: moderate peak power (~4.5 GW, P/Pc ~ 0.2), dielectric
mirrors. The input follows the authors' own simulation of this stage (Müller et al., Opt. Lett. 46,
2678, 2021): Gaussian beam, Gaussian 200 fs pulse of 994 uJ with a TOD of -1e4 fs^3.

                 paper                                          used here
mirrors          RoC 0.6 m, R > 99.95 %, |GDD| < 50 fs^2         R = 0.9995, GDD = +35 fs^2, band
                 over 970-1130 nm                               edges 10 nm outside (assumption)
geometry         d = 1183 mm, 26 passes, re-entrant              herriott(R=0.6, N=26, k=1)
eigenmode        0.30 mm diameter at focus, 2.5 mm on mirror    computed
gas              Ar 700 mbar, n2 = 1e-23 m^2/W at 1 atm          same
injection        linear eigenmode                                same
compressor       6 chirped mirrors, -1923 fs^2                   same GDD

Measured: -20 dB width ~120 nm, Fourier limit 27 fs, compressed 31 fs (autocorrelation), 96 %
transmission (cell + compressor), M2 < 1.15, weighted homogeneity 98.7 % (x) / 99.4 % (y).
Not modelled: folded off-axis geometry, windows, measured input spectrum and phase.

Usage: python bench_grebing2020_1mJ.py [--quick] [--device gpu] [--set n2_1bar=1.1e-23] ...
       (python bench_grebing2020_1mJ.py -h for all options)

Reference run

run

run_fc5327fc, 2026-11-05

code

thunder4d 1.0.0, git ae152b3, LensFrameSimulation

grid

Grid 72x72x120 (5 MB per field, cpu/scipy) | box 1.30 x 1.30 mm, dx = 18.1 um | T = 1695 fs, dt = 14.13 fs | lambda window 920-1173 nm

steps

phi_max = 0.02 rad, gouy_step = 0.05 rad, 1559 steps

run time

26 passes in 0.8 min (cpu, scipy)
../_images/grebing2020_1mJ.png

Fig. 5 Standard figure of the reference run. Top: transmission, HG₀₀ fraction, homogeneity and B-integral vs pass; beam radius and peak intensity at the cell centre; output spectrum (with the measured or published spectrum when available). Bottom: compressed pulses vs the Fourier limit; output spatio-spectral trace S(θ, λ); fluence on the last mirror.

Comparison with the paper

output

simulation

paper

deviation

status

description

w0_um

153.4 um

150 ±5%

+2 %

ok

linear eigenmode waist (1/e2 radius) (0.30 mm diameter)

w_mirror_um

1273 um

1250 ±5%

+2 %

ok

linear mode on mirror (1/e2 radius) (2.5 mm diameter)

transmission

0.9843

0.96 ±0.03

+3 %

ok

cell transmission (cell + compressor in the paper)

B_rad

25.57 rad

13

+97 %

B-integral, on-axis peak (~13 beam-averaged)

edge_fraction

6.637e-07

< 0.001

-100 %

ok

max fluence fraction outside 70 % of the box (should be ~0) (numerical check)

M2x

1.001

< 1.15

-13 %

ok

M2 x (spectrally weighted)

M2y

1.001

< 1.15

-13 %

ok

M2 y (spectrally weighted)

span20_nm

136.7 nm

120 ±15%

+14 %

ok

-20 dB spectral width

ftl_fs

26.04 fs

27 ±10%

-4 %

ok

Fourier limit (integrated spectrum)

comp_fs

26.85 fs

31 ±15%

-13 %

ok

compressed with the paper’s -1923 fs2 (autocorrelation)

V_weighted_x

0.9999

> 0.987

+1 %

ok

homogeneity, intensity weighted in 1/e2 (x) (measured; the ideal cell can only do better)

d_mm

1183 mm

1183 ±0%

-0 %

ok

mirror separation

Other outputs

output

simulation

description

w0_injected_um

153.4 um

injected waist (linear)

P_over_Pc

0.1936

input peak power / critical power

B_estimate_rad

32.5 rad

B-integral, matched-mode estimate

I_peak_max_Wcm2

1.502e+13 W/cm2

max peak intensity at the cell centre

F_mirror_max_Jcm2

0.0462 J/cm2

max fluence on the mirrors

eta00_final

0.9995

HG00 fraction, output

w_breathing

0.1456

beam-size oscillation (max-min)/w_in

rms_width_nm

30.89 nm

RMS spectral width

lambda_centroid_nm

1028 nm

spectral centre of mass

comp_peak_ratio

0.9019

peak power / Fourier limit (paper GDD)

best_gdd_fs2

-2026 fs2

GDD maximising the peak power

best_comp_fs

26.72 fs

compressed with the best GDD

best_peak_ratio

0.9357

peak power / Fourier limit (best GDD)

best_peak_power_GW

32.32 GW

compressed peak power (best GDD)

V_min_fwhm

0.9998

min homogeneity within FWHM

V_min_e2

0.9990

min homogeneity within 1/e2

Measured data

Curves digitised from the paper, in benchmark/ (see the header of each file for the figure and the units):

  • none committed yet

Reproducing

cd benchmark
python bench_grebing2020_1mJ.py --device cpu
python analyze.py grebing2020_1mJ