387-nm Generation in GdxY1-xCa4O(BO3)3 Crystal and Its Utilization for 193-nm Light Source

We report on near-UV generation in GdxY1-xCa4O(BO3)3 crystals used under type-I non-critical phase-matching conditions. GdxY1-xCa4O(BO3)3 was also applied to a 193-nm deep-UV laser source based on the eighth harmonic of an erbium-doped fiber amplifier output at 1547 nm, in which GdxY1-xCa4O(BO3)3 (x = 0.68) was used for 387-nm generation. Using this compact light source, 5% conversion efficiency from the 1547-nm input to the 193-nm output was achieved at a fundamental peak power of 18 kW.