A silicon nitride microdisk resonator with a 40-nm-thin horizontal air slot

Abstract

We design and fabricate pedestal-type, 15 mu m diameter silicon nitride microdisk resonators on Si chip with horizontal air-slot using selective wet etching between Si, SiO(2), and SiN(x). As the slot structure is determined by deposition process, air slots that are as thin as 40 nm and as deep as 5 mu m with ultra-smooth slot surfaces can easily be fabricated with photolithography only. Fundamental TM-like slot mode in which the E-field is greatly enhanced within slot was observed with an intrinsic Q factor of similar to 34,000 (lambda(res) = 1523.7nm) and energy overlap in slot region of 21.6%. (C) 2010 Optical Society of America