Diamond micro-lenses with variable height using self-assembly silica-microsphere-monolayer as etching mask

Abstract

Diamond micro-lenses have potential applications in quantum information processing and high power lasers. Diamond micro-lenses have been fabricated through focused ion beam milling or laser machining followed by mechanical polishing, which are not scalable. Photoresist reflow and plasma etching can fabricate diamond micro-lenses but only with a relatively shallow curvature. In this work, we report the fabrication of diamond micro-lenses with variable height. Silica microspheres with diameters of 2.5 and 3.2μm are dispersed on the diamond surface to form a monolayer as etching mask, following with plasma etching which is used to transfer the spherical shape into diamond substrate. The height of diamond microlens can be tuned by changing the gas mixture ratios. Scanning electron microscope (SEM) has been used to verify the profiles of the micro-lenses. This method is useful for the fabrication of large arrays of diamond micro-lenses for photonic applications.