RESUMEN
We report an efficient deep-UV master-oscillator power amplifier (MOPA) laser system at 229â nm that generates 350 ps pulses at 2â 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 4F3/2â4I9/2 transition allows high-power laser emission of up to 28 W near 915â nm in the sub-nanosecond regime with low spectral 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 demonstrates the great potential of Nd3+-doped fiber lasers to produce high-power deep-UV emission.
RESUMEN
We present a compact passively mode-locked fiber laser emitting near 910 nm with an all-polarization-maintaining fiber laser architecture. The ring-cavity laser configuration includes a core-pumped neodymium-doped fiber as a gain medium and a semiconductor saturable absorber mirror as a passive mode-locking element. A bandpass filter is used to suppress parasitic emission near 1.06 µm and allows wavelength tuning between 903 and 912 nm. The laser operates in a highly stable and self-starting all-normal-dispersion regime with a minimum pulse duration of 8 ps at 28.2 MHz pulse repetition rate and 0.2 nJ maximum pulse energy. A single-pass amplifier stage increases the pulse energy up to 1.5 nJ, and pulse compression with a pair of gratings is demonstrated with nearly Fourier transform limited pulses.