Technical assessment of a 100W CW fiber laser amplifier for Fourier telescopy imaging

Fourier Telescopy Imaging technique requires coherent laser beams generate high contrast interference fringes at remote object of interest. We have built a narrow spectral linewidth 100W CW fiber laser amplifier and measured its output beam coherent phase with respect to seeding laser's phase. We have demonstrated that the fiber laser amplifier that we built conserved the coherent phase of its seeding source. Clear interference fringes were obtained by an interferometer between the 100W fiber laser amplifier output and its seeding laser, without any active phase control element. Our assessment shows that fiber laser amplifiers meet Fourier Telescopy imaging requirements.