Single input Spherical Microbubble Resonator

• DOI: 10.1364/fio.2011.ftun3
• Publication Date: 2013-04-09T17:05:43Z
• Authors: Sίle Nic Chormaic; Amy Watkins; Jonathan Ward; Yuqiang Wu
• Keywords: 0103 physical sciences; 0211 other engineering and technologies; 02 engineering and technology; 01 natural sciences

A single-input whispering gallery optical microbubble resonator is presented. Spherical microbubbles with diameters less than 100 μm, micrometer-sized wall thicknesses, and a single opening or input were fabricated by heating the tapered tip of a pressurized glass capillary using a CO(2) laser. Optical whispering gallery modes with Q factors of ∼10(5) were obtained. The bubbles were filled with water and mode shifts of ∼20 GHz were observed. Fano-type resonances were detected when the coupling optical fiber diameter was less than 1 μm, causing the microresonator to switch from being a band-stop filter to a bandpass filter. Larger bubbles with submicrometer wall thickness were also fabricated.