paper

Ultrafast laser inscription of mid-IR directional couplers for stellar interferometry

arXiv:1408.5953 · doi:10.1364/OL.39.004820

Abstract

We report the ultrafast laser fabrication and mid-IR characterization (3.39 microns) of four-port evanescent field directional couplers. The couplers were fabricated in a commercial gallium lanthanum sulphide glass substrate using sub-picosecond laser pulses of 1030 nm light. Straight waveguides inscribed using optimal fabrication parameters were found to exhibit propagation losses of 0.8 dB/cm. A series of couplers were inscribed with different interaction lengths, and we demonstrate power splitting ratios of between 8% and 99% for mid-IR light with a wavelength of 3.39 microns. These results clearly demonstrate that ultrafast laser inscription can be used to fabricate high quality evanescent field couplers for future applications in astronomical interferometry.

arXiv comment4 pages, 4 figures

References in corpus (13)

Cited by in corpus (8)