Periodically poled potassium titanyl phosphate yields femtosecond optical parametric oscillator
Researchers at Bilkent University (Ankara, Turkey) have demonstrated a femtosecond optical parametric oscillator (OPO) based on bulk periodically poled potassium titanyl phosphate (KTP). The OPO, pumped by an ultrafast Ti:sapphire laser at 758 nm, generates a signal output at 1200 nm and an idler output at 2060 nm. Quasi-phase-matching in the KT¥crystal is achieved with a grating period of 24 µm.
Despite high cavity losses resulting from a 70% reflective output coupler and uncoated crystal facets, the maximum signal power conversion efficiency of the device is 22%, with a pum¥depletion of 69%. The OPO can be tuned rapidly over a 200-nm band in the signal branch by adjusting the cavity length with a piezocontrolled mirror. The Bilkent University group, headed by Orhan Aytur, has collaborated with scientists at Koç University (Istanbul, Turkey) and IBM Almaden Research Center (San Jose, CA) in this research.