35/250 ytterbium-doped LMA polarization-maintaining fiber for high average and high peak power amplifiers

Abstract

An ytterbium-doped large mode area polarization-maintaining fiber with core/cladding diameters of 35/250 µm was fabricated from modified chemical vapor deposition technique and solution doping process. High cladding absorption and low photodarkening were achieved from aluminophosphosilicate core glass with optimal molar composition. The fiber was tested as a power amplifier using a 1064-nm narrow-linewidth laser oscillator with 34 ps pulse duration and 120 MHz pulse repetition frequency. The slope efficiency was seen to exceed 80% while the average output power was scaled beyond 420 W, before the onset of transverse mode instability. The fabricated fiber also yields near diffraction-limited output, narrow spectral linewidth and high polarization extinction ratio.

Picosecond Pulse Tapered Fiber Amplifier Operated near 1030 nm with Peak Power up to 1 MW

“…This approach has seriously inferior reliability in fiber fusion splicing and requires periodic alignment, and therefore, as a rule, is unacceptable for commercial implementation. If we consider systems with all-fiber signal input, LMA SIFs have an order-of-magnitude lower peak power-tens to hundreds of kW [14][15][16], and this is the kind of fiber used in commercially available systems. T-YDFs also have all-fiber signal input, but at the same time, they allow a MW level of output peak power to be achieved [17][18][19][20].…”