Abstract
Spectral compression is a way to enhance spectral brightness. On the other hand, the energy is redistribution on the spectrum. It can raise up the signal-to-noise ratio, which is helpful in spectroscopic application. Spectral compression is reverse process of adiabatic soliton temporal compression. Nevertheless, the feasibility for spectral compression would be seemingly limited by the dispersion ramp of dispersion-increasing fiber (DIF). But, if the input pulse duration is narrow enough, it would be possible that the real spectral compression ratio (SCR) breakthrough the ideal fiber limitation. Our laser source is 56 femtosecond pulse width. We successfully used it to generate single and dual-peak spectra with high SCR in DIF. SCR of single peak achieved 101.1 times, and SCR of dual-peak severally achieved lager than 80 times at simultaneously. Which the number is beyond ideal ratio of 22.5. Moreover, no matter is single or dual-peak spectra, the relative amplitude and wavelength are tunable. We can adjust it by average power and input pulse chirp condition. Compare to the experimental and simulation results, we could find it has a great agreement.