Five optical cycle pulse generation in the mid-IR using aperiodically poled lithium niobate

Summary form only given. The design of nonlinear crystals with novel phase-matching characteristics based on quasi-phase matching (QPM) has enabled the parametric generation of a wide range of wave lengths at high conversion efficiencies within the femtosecond regime. Femtosecond QPM optical parametric oscillators (OPOs) that use crystals with a uniform grating are subject to bandwidth limiting effects such as temporal walk-away and frequency up/back conversion, which become increasingly more significant for shorter pump pulses. These effects can be minimized by designing crystals with nonuniform grating periods to match a chirped broad-bandwidth pump pulse. If the signal wave is assumed narrow bandwidth then an approximately chirped pump pulse can be arranged to combine with the signal wave at differing positions throughout the crystal such that all idler components will leave simultaneously, as a transform-limited pulse. We present the results of an aperiodically poled lithium niobate (APPLN) OPO.