Femtosecond laser written diamond waveguides - a step towards integrated photonics in the far infrared

TL;DR

This paper reports the first detailed demonstration and characterization of mid-infrared diamond waveguides written with femtosecond lasers, showing their potential for integrated photonics in the far infrared.

Contribution

It provides the first complete characterization of femtosecond laser written diamond waveguides for mid-infrared wavelengths, including dispersion analysis and material impact assessment.

Findings

Waveguides designed for 2.4 um and 8.6 um wavelengths.

Total dispersion dominated by bulk diamond material.

Laser modifications introduce negligible perturbations to the intrinsic material.

Abstract

A first demonstration and complete characterization of mid-infrared waveguides in diamond are reported in detail. Waveguides were designed for 2.4 um and 8.6 um waveguiding, with their group velocity dispersion was analyzed using femtosecond pulses at 2.4 um wavelength propagated through the waveguide and the bulk substrate. The total dispersion was found to be dominated by the bulk material rather than the waveguide, and was on the range of 275 fs2/mm, demonstrating that femtosecond laser written modifications in diamond introduce negligible perturbations to the intrinsic material.