title: Efficient light coupling into in-plane semiconductor nanomembrane photonic devices utilizing a sub-wavelength grating coupler.
abstract: We report a subwavelength grating (SWG) coupler for coupling light efficiently into in-plane semiconductor nanomembrane photonic devices for the first time. The SWG coupler consists of a periodic array of rectangular trenches fabricated on a silicon nanomembrane (SiNM) transferred onto a glass substrate. At a wavelength of 1555.56 nm, the coupling efficiency of the fabricated 10 µm wide, 17.1 µm long SWG is 39.17% (-4.07 dB), with 1 dB and 3 dB bandwidths of 29 nm and 57 nm, respectively. Peak efficiency varies by 0.26 dB when measuring 5 fabricated grating pairs. Coupling efficiency can further be improved with an improved SiNM transfer process. Such high efficiency couplers allow for the successful realization of a plethora of hybrid photonic devices utilizing nanomembrane technology.
authors.affiliation: Omega Optics, Inc, 10306 Sausalito Dr, Austin, Texas 78759, USA. harish.subbaraman@omegaoptics.com
authors.forename: Harish
authors.initials: H
authors.lastname: Subbaraman
authors.forename: Xiaochuan
authors.initials: X
authors.lastname: Xu
authors.forename: John
authors.initials: J
authors.lastname: Covey
authors.forename: Ray T
authors.initials: RT
authors.lastname: Chen
mesh_terms: D004735:Energy Transfer; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008567:Membranes, Artificial; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology / Q000295:instrumentation*; D012031:Refractometry / Q000295:instrumentation*; D012666:Semiconductors
chemical_list: D008567:Membranes, Artificial