Variation of electron density in spectral broadening process in solid thin plates at 400 nm* *Project supported by the National Key Research and Development Program of China (Grant No. 2017YFB0405202), the Major Program of the National Natural Science Foundation of China (Grant No. 61690221), and the General Program of the National Natural Science Foundation of China (Grant No. 11774277).

Abstract

The generation of continuous spectrum centered at 400 nm from solid thin plates is demonstrated in this work. A continuum covering 365 nm to 445 nm is obtained when 125-μJ frequency-doubled Ti:sapphire laser pulses are applied to six thin fused silica plates at 1-kHz repetition rate. The generalized nonlinear Schrödinger equation simplified for forward propagation is solved numerically, the spectral broadening with the experimental parameters is simulated, and good agreement between simulated result and experimental measurement is achieved. The variation of electron density in the thin plate and the advantage of a low electron density in the spectral broadening process are discussed.