High power, tunable, ultrafast yellow laser using cascaded second harmonic generation of mid-IR Cr2+:ZnS laser in MgO:PPLN crystals

Anirban Ghosh, Deepika Yadav, Ravi Kiran Saripalli, Goutam K. Samanta

Abstract

We report on efficient, two stage single-pass second harmonic generation of ultrafast Cr2+:ZnS laser with spectral bandwidth of 138 nm centered at ~2360 nm and pulse width of ~43 fs at a repetition rate of 80 MHz into tunable yellow radiation across 577 – 589 nm in multi-grating MgO:PPLN crystals. A maximum average output power ~940 mW at 589 nm wavelength with a single-pass conversion efficiency as high as 41% was achieved. The yellow radiation has a spectral bandwidth of 2 nm and pulse-width of ~913 fs in absence of any pulse compression with a time-bandwidth product of 1.58.