title: Highly efficient picosecond diamond Raman laser at 1240 and 1485 nm.
abstract: We present a highly efficient picosecond diamond Raman laser synchronously-pumped by a 4.8 W mode-locked laser at 1064 nm. A ring cavity was adopted for efficient operation. With a low-Q cavity for first-Stokes 1240 nm, we have achieved 2.75 W output power at 1240 nm with 59% overall conversion efficiency. The slope efficiency tended towards 76% far above the SRS threshold, approaching the SRS quantum limit for diamond. A high-Q first-Stokes cavity was employed for second-Stokes 1485 nm generation through the combined processes of four-wave mixing and single-pass stimulated Raman scattering. Up to 1.0 W of second-stokes at 1485 nm was obtained, corresponding to 21% overall conversion efficiency. The minimum output pulse duration was compressed relative to the 15 ps pump, producing pulses as short as 9 ps for 1240 nm and 6 ps for 1485 nm respectively.
authors.forename: Aravindan M
authors.initials: AM
authors.lastname: Warrier
authors.forename: Jipeng
authors.initials: J
authors.lastname: Lin
authors.forename: Helen M
authors.initials: HM
authors.lastname: Pask
authors.forename: Richard P
authors.initials: RP
authors.lastname: Mildren
authors.forename: David W
authors.initials: DW
authors.lastname: Coutts
authors.forename: David J
authors.initials: DJ
authors.lastname: Spence