Two-photon polarization-selective etching of emergent nano-structures on diamond surfaces

Abstract

Optical techniques have advanced considerably in recent years to enable processing of surfaces with a resolution less than the wavelength of light. Despite the highly selective nature of light-matter interactions, however, efforts to increase resolution to the scale of single atoms are hampered by rapid and efficient dissipation of the absorbed energy to the surrounding matrix. Here we show that two-photon surface excitation using ultraviolet light provides a method for selectively removing carbon from diamond surfaces. Polished surfaces etched by this method develop ultra-deep subwavelength structures with morphologies dependent on the polarization of the incident laser with respect to the crystal axes. As well as revealing a practical and versatile method for nano-patterning of diamond surfaces, we show that the results comprise mesoscopic evidence for bond scission via a highly localized optical interaction that may lead to the development of new optical approaches for ultra-nanoscale (o10 nm) surface structuring.

Dynamic Pattern Formation in Electron-Beam-Induced Etching

“…However, the new model provides a more compelling explanation for EBIE observed at cryogenic temperatures [35] since it does not require thermal desorption of the reaction products. Moreover, the new model is unique in being consistent with reports of UV laser induced etching of diamond, that is believed to proceed through a two photon C-C bond scission mechanism [8]. The new model also provides a satisfactory explanation for the fact that single crystal diamond can be etched by EBIE in the first place.…”

“…Pattern formation is a ubiquitous process that provides fundamental insights into the roles of symmetry breaking, anisotropy and nonlinear interactions in emergent phenomena [6][7][8]. Here it reveals a chemical etch rate anisotropy that can not be explained by established EBIE theory.…”

Diamond Nanophotonics

“…This can yield either standalone nanodiamonds with uniform size or microdisk cavities or waveguides with various shapes. In an alternative fabrication method, it was shown that diamond single crystals that are exposed to 266 nm laser pulses at moderate powers of half of the ablation threshold exhibited etch patterns of hundred nanometers [153] . Furthermore, the patterns were polarization dependent; When the polarization is parallel to [110] (E|| [110]), the pattern consists of faceted ridges oriented perpendicular to the polarization, while if the alignment is along the cubic direction E|| [100], the pattern consists of a cross hatched or grid-like structure oriented within a few degrees of [110].…”

Utilizing dynamic laser speckle to probe nanoscale morphology evolution in nanoporous gold thin films

“…However, the historically quasi-static nature of this technique (i.e. the measurement of light scattering from objects fixed or slowly varying in space) is not amenable to integration with the wide array of the fast dynamics of laser microprocessing platforms that have seen a rise in recent years for a myriad of applications ranging from direct laser cutting/machining, ablating, additive manufacturing processes, as well as laser-induced periodic surface structure formation (LIPSS) [4][5][6][7][8].…”