Watt-level deep-UV subnanosecond laser system based on Nd-doped fiber at 229 nm

We report an efficient deep-UV master-oscillator power amplifier (MOPA) laser system at 229 nm that generates 350 ps pulses at 2 MHz repetition rate with an average power of 1.2 W. The use of a polarization-maintaining large mode area neodymium-doped fiber operating on the 4F3/2 -> 4I9/2 transition allows high-power laser emission of up to 28 W near 915 nm in the sub-nanosecond regime with low spec-tral broadening. Two nonlinear frequency conversion stages (LBO + BBO crystals) in a single-pass configuration directly convert the IR laser emission to deep UV. This laser demon-strates the great potential of Nd3+-doped fiber lasers to produce high-power deep-UV emission.(c) 2023 Optica Pub-lishing Group

Automated summary

We present an efficient deep-UV master-oscillator power amplifier (MOPA) laser system with a wavelength of 229 nm. It generates 350 ps pulses at a repetition rate of 2 MHz, delivering an average power of 1.2 W. By utilizing a polarization-maintaining large mode area neodymium-doped fiber, high-power laser emission of up to 28 W at sub-nanosecond regime with low spectral broadening is achieved. The infrared laser emission is directly converted to deep-UV through two nonlinear frequency conversion stages (LBO + BBO crystals). This study demonstrates the great potential of Nd3+-doped fiber lasers in producing high-power deep-UV emission.