Compact high repetition rate femtosecond optical parametric generator and amplifier pumped by femtosecond Yb fiber laser

Abstract

Tunable near-infrared femtosecond laser sources are attractive for optical nonlinear techniques such as time resolved optical spectroscopy and multi-photon fluorescence microscopy [1]. Furthermore high repetition rate is desirable to reduce acquisition time of the measurements. Compact and aligning-free system is preferable for practical issues [2]. Development of high average power passively mode-locked solid state and fiber lasers allowed the realization of single pass optical parametric generators (OPGs) based on short LiNbO 3 and LiTaO 3 crystals with repetition rates of several tens of megahertz and pulse durations in the femtosecond regime [3]. Various configurations of OPGs or optical parametric amplifiers (OPAs) based on a multiperiod magnesium oxide-doped periodically poled lithium niobate (MgO: PPLN) crystals were demonstrated previously [1-4]. In this work we demonstrate a compact double pass OPG/OPA system, based on single MgO:PPLN crystal with a fan-out pattern. Fan-out design allows fine tuning of generation wavelength without adjusting temperature of PPLN crystal.