title: High-power, continuous-wave, single-frequency, all-periodically-poled, near-infrared source.
abstract: We report a high-power, single-frequency, continuous-wave (cw) source tunable across 775-807 nm in the near-infrared, based on internal second harmonic generation (SHG) of a cw singly-resonant optical parametric oscillator (OPO) pumped by a Yb-fiber laser. The compact, all-periodically-poled source employs a 48-mm-long, multigrating MgO doped periodically poled lithium niobate (MgO:PPLN) crystal for the OPO and a 30-mm-long, fan-out grating MgO-doped stoichiometric periodically poled lithium tantalate (MgO:sPPLT) crystal for intracavity SHG, providing as much as 3.7 W of near-infrared power at 793 nm, together with 4 W of idler power at 3232 nm, at an overall extraction efficiency of 28%. Further, the cw OPO is tunable across 3125-3396 nm in the idler, providing as much as 4.3 W at 3133 nm with >3.8  W over 77% of the tuning range together with >3  W of near-infrared power across 56% of SHG tuning range, in high-spatial beam-quality with M2<1.4. The SHG output has an instantaneous linewidth of 8.5 MHz and exhibits a passive power stability better than 3.5% rms over more than 1 min.
authors.affiliation: ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, Castelldefels, Barcelona 08860, Spain. kavita.devi@icfo.es
authors.forename: Kavita
authors.initials: K
authors.lastname: Devi
authors.forename: S
authors.initials: S
authors.lastname: Chaitanya Kumar
authors.forename: M
authors.initials: M
authors.lastname: Ebrahim-Zadeh
mesh_terms: D000669:Amplifiers, Electronic; D004735:Energy Transfer; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D007259:Infrared Rays; D007834:Lasers; D009991:Oscillometry / Q000295:instrumentation*