Tel: +86-592-5601404
Fax: +86-592-5563272

Address: #506B, Henghui Business Center,No.77,Lingxia Nan Road, High Technology Zone, Huli, Xiamen,361006
Home > News > Spectral broadening induced by intense ultra-short pulse in 4H SiC crystals
Spectral broadening induced by intense ultra-short pulse in 4H SiC crystals

We report the observation of spectral broadening induced by 200 femtosecond laser pulses with the repetition rate of 1 kHz at the wavelength of 532 nm in semi-insulating 4H–SiC single crystals. It is demonstrated that the full width at half maximum of output spectrum increases linearly with the light propagation length and the peak power density, reaching a maximum 870 cm−1 on a crystal of 19 mm long under an incident laser with a peak power density of 60.1 GW/cm2. Such spectral broadening can be well explained by the self-phase modulation model which correlates time-dependent phase change of pulses to intensity-dependent refractive index. The nonlinear refractive index n 2 is estimated to be 1.88×10−15 cm2/W. The intensity-dependent refractive index is probably due to both the nonlinear optical polarizability of the bound electrons and the increase of free electrons induced by the two-photon absorption process. Super continuum spectra could arise as crystals are long enough to induce the self-focusing effect. The results show that SiC crystals may find applications in spectral broadening of high power lasers.

source: iopscience

For more information, please visit our website:,

send us email at and