title: Broadly wavelength- and pulse width-tunable high-repetition rate light pulses from soliton self-frequency shifting photonic crystal fiber integrated with a frequency doubling crystal.
abstract: Soliton self-frequency shift (SSFS) in a photonic crystal fiber (PCF) pumped by a long-cavity mode-locked Cr:forsterite laser is integrated with second harmonic generation (SHG) in a nonlinear crystal to generate ultrashort light pulses tunable within the range of wavelengths from 680 to 1800 nm at a repetition rate of 20 MHz. The pulse width of the second harmonic output is tuned from 70 to 600 fs by varying the thickness of the nonlinear crystal, beam-focusing geometry, and the wavelength of the soliton PCF output. Wavelength-tunable pulses generated through a combination of SSFS and SHG are ideally suited for coherent Raman microspectroscopy at high repetition rates, as verified by experiments on synthetic diamond and polystyrene films.
authors.affiliation: Physics Department, International Laser Center, MV Lomonosov Moscow State University, Moscow 119992, Russia.
authors.forename: Aleksandr A
authors.initials: AA
authors.lastname: Lanin
authors.forename: Andrei B
authors.initials: AB
authors.lastname: Fedotov
authors.forename: Aleksei M
authors.initials: AM
authors.lastname: Zheltikov