High-power, high repetition-rate, ultrafast fibre laser based source of DUV radiation at 266 nm

Abstract

We report on a compact, high-power, high repetition-rate, ultrafast source of deep ultraviolet (DUV) radiation. Using a Yb-fibre laser at 1064 nm producing 260 fs output pulses at a 78 MHz repetition rate and usingtwo stage single-pass frequency-doubling, we have generated ultrafast DUV radiation at 266 nm. The fibre laser is first frequency-doubled into green at 532 nm using a LBO crystal with output power as high as 2.4 W and with a conversion efficiency of ∼ 50%. Further, the generated green is frequency-doubled in BBO crystal generating DUV radiation with an output power as high as 616 mW corresponding with near-IR to DUV conversion efficiency of ∼ 12.8%.