Laser Ablated Nanocrystalline Diamond Membrane for Infrared Applications

We are reporting on laser microstructuring of thin nanocrystalline diamond membranes, for the first time. To demonstrate the possibility of microstructuring, we fabricated a diamond membrane, of 9 mu m thickness, with a two-dimensional periodic array of closely located chiral elements. We describe the fabrication technique and present the results of the measurements of the infrared transmission spectra of the fabricated membrane. We theoretically studied the reflection, transmission, and absorption spectra of a model structure that approximates the fabricated chiral metamembrane. We show that the metamembrane supports quasiguided modes, which appear in the optical spectra due to grating-assisted diffraction of the guided modes to the far field. Due to the C-4 symmetry, the structure demonstrates circular dichroism in transmission. The developed technique can find applications in infrared photonics since diamond is transparent at wavelengths > 6 mu m and has record values of hardness. It paves the way for creation of new-generation infrared filters for circular polarization.

Automated summary

This paper reports on the laser microstructuring of thin nanocrystalline diamond membranes for the first time. A diamond membrane with a two-dimensional periodic array of closely located chiral elements was fabricated to demonstrate the possibility of microstructuring. The fabrication technique is described, and the measured infrared transmission spectra of the fabricated membrane are presented. The theoretical study shows that the metamembrane supports quasiguided modes and exhibits circular dichroism in transmission. The developed technique has potential applications in infrared photonics and can pave the way for new-generation infrared filters for circular polarization.