Diamond optical vortex generator processed by ultraviolet femtosecond laser

Area of Science:

• Materials Science
• Optics
• Nanotechnology

Background:

• Diamond's unique properties make it ideal for optical applications.
• Existing diamond processing methods face challenges in achieving high precision and surface quality.
• Micro-optical components require advanced fabrication techniques for miniaturization.

Purpose of the Study:

• To develop a precise diamond micromachining method combining laser writing and chemical treatment.
• To investigate the impact of laser ablation byproducts on diamond surface morphology.
• To fabricate and characterize spiral zone plates (SZPs) on diamond for micro-optical vortex generation.

Main Methods:

• Utilized ultraviolet femtosecond laser direct writing for diamond surface patterning.
• Employed a mixed acid heating chemical treatment to refine laser-processed surfaces.
• Analyzed the chemical composition of ablated clusters and their effect on surface morphology.
• Fabricated diamond SZPs and evaluated their optical performance through experiments and simulations.

Main Results:

• Achieved significant reduction in surface roughness for both pristine (20.5 nm to 0.64 nm) and processed (37.4 nm to 9.4 nm) diamond regions.
• Successfully inscribed spiral zone plates (SZPs) on high-pressure, high-temperature diamond.
• Experimental and simulation results for diamond SZP optical performance showed high consistency.

Conclusions:

• The proposed laser-chemical auxiliary processing method offers precise control over diamond surface micromachining.
• This technique effectively reduces surface roughness and enables the fabrication of complex micro-optical elements.
• The developed method is crucial for the integration and miniaturization of diamond-based optical components.