Waveguide writing in fused silica with a femtosecond fiber laser at 522 nm and 1 MHz repetition rate

TLDR

The study reports waveguide fabrication in fused silica using a commercial femtosecond fiber laser system. The authors examined how repetition rate, focal area, pulse energy, scan speed, and wavelength affect waveguide writing. Waveguides could not be produced at the fundamental 1045 nm wavelength, but telecom‑compatible waveguides with propagation losses below 1 dB/cm at 1550 nm were achieved at the second‑harmonic 522 nm wavelength using 115 nJ/pulse at 1 MHz.

Abstract

We report on waveguide writing in fused silica with a novel commercial femtosecond fiber laser system (IMRA America, FCPA microJewel). The influence of a range of laser parameters were investigated in these initial experiments, including repetition rate, focal area, pulse energy, scan speed, and wavelength. Notably, it was not possible to produce low-loss waveguides when writing with the fundamental wavelength of 1045 nm. However, it was possible to fabricate telecom-compatible waveguides at the second harmonic wavelength of 522 nm. High quality waveguides with propagation losses below 1 dB/cm at 1550 nm were produced with 115 nJ/pulse at 1 MHz and 522 nm.