wang_2013#

D. Wang, Y. Leng and Z. Xu, “Measurement of nonlinear refractive index coefficient of inert gases with hollow-core fiber”, Appl. Phys. B 111, 447 (2013)

Source record · Catalogue · Review register

DOI: 10.1007/s00340-013-5354-0

Source kind: measurement

Recorded technique: Self-phase-modulation spectral broadening in a gas-filled hollow-core fiber (1 m long; 250 um inner diameter at 800 nm, 400 um at 1.8 um): near transform-limited input pulses (800 nm: 0.46 mJ (Ar) or 0.66 mJ (Ne), 50 fs FWHM; 1.8 um: 1.27 mJ, 57 fs from an OPA) coupled to the fundamental mode; the rms spectral broadening factor versus gas pressure (up to ~1 bar Ar, 2.6 bar Ne, 0.5 bar Ar at 1.8 um) gives n2 through Eq. (1); n2 per bar from the slope of a linear fit, corrected for the 2-4 % extra broadening near the fiber ends (pp. 447-449).

Materials in structured entries: Ar, Ne

Dataset quantities: nonlinear_index

Contents: 6 datasets; 0 formulas.

Curation notes#

Journal pages 447-452 = PDF pages 1-6. Identity checked against the first page. Ne and Ar (Kr and Xe were not measured: ionization dominates at these intensities, p. 450).

DEFINITIONS (p. 448): Delta omega_out / Delta omega_in = (1 + (4 / 3 sqrt 3) phi_max^2)^(1/2) (Eq. (1), transform-limited Gaussian), phi_max = gamma P0 L_eff, L_eff = [1 - exp(-alpha L)] / alpha, gamma = n2 omega0 / (c A_eff), A_eff = 0.48 pi a^2 (HE11 mode); rms widths, Eqs. (2)-(3). n2 is the SELF coefficient (single-beam SPM, n = n0 + n2 I). Validity: the Kerr length is required to be well below the dispersion, self-steepening and ionization lengths (Tables 1-4, characteristic lengths per pressure).

VALUES (text only): Ar at 800 nm, slope ‘(1.11 +- 0.05) x 10^-19 cm2/W bar’, ‘Considering the 2-4 % extra contribution near the input and output end of the fiber, the n2 of argon is (1.08 +- 0.06) x 10^-19 cm2/W bar which agrees well the value of 1.0 x 10^-19 cm2/W bar given in [19]’ (p. 449). Ne at 800 nm: ‘Linear fitting followed by a correction results in an average n2 of (9.30 +- 0.25) x 10^-21 cm2/W bar compared with 7.5 x 10^-21 cm2/W bar in [20]’ (p. 450). Ar at 1.8 um: ‘(6.65 +- 0.33) x 10^-20 cm2/W bar while the calculated value is 9.73 x 10^-20 cm2/W bar at 1.83 um in [21]’ (p. 450). The +- are fit statistics. Accuracy (p. 451): self-steepening (overestimate, Ne) and plasma (underestimate, Ar at 1.8 um) ‘cause a deviation of about +-30 % from the referred values’; chirped or non-Gaussian input would lower n2. Not a stated uncertainty: kept in notes.

REFERENCE STATE: per bar (‘cm2/W bar’), temperature not stated: 1e5 Pa and 293.15 K assumed; n2 was found linear in pressure over the range. Wavelengths: the laser centre wavelengths (800 nm; 1.8 um, OPA tunable 1.6-2.0 um), vacuum assumed.

PART: electronic (atoms, 50-57 fs), with the residual self-steepening and plasma effects discussed above. [19] = bejot_2010 (PRL 104, 103903), [20] = Nurhuda et al., Appl. Phys. B 89, 209 (2007) (not in the library), [21] = Bejot et al., PRA 81, 063828 (2010) = bejot_2010_hollow.

Recorded bibliographic identity status: VALIDATED. This concerns identification of the source; it does not establish the scientific correctness of its contents.