title: Add-drop filter based on TiO2coated shifted Bragg grating.
abstract: We present a titanium dioxide coated shifted Bragg grating in a silicon-on-insulator platform enabling optical add-drop functionality. The device works on the basis of mode conversion due to shifted sidewall structure followed by mode splitting based on an asymmetric Y-coupler. We experimentally demonstrate the working principle of the device. A reflection bandwidth of 2.2 nm with 14 dB extinction ratio is obtained with a 300 μm long shifted Bragg grating. The performance of the device is also compared without the titanium dioxide coating. A scope of spectral tunability with titanium dioxide re-coating (0.8 nm per 1 nm re-coating) by atomic layer deposition is experimentally verified.
authors.forename: Somnath
authors.initials: S
authors.lastname: Paul
authors.forename: Ismo
authors.initials: I
authors.lastname: Vartiainen
authors.forename: Matthieu
authors.initials: M
authors.lastname: Roussey
authors.forename: Toni
authors.initials: T
authors.lastname: Saastamoinen
authors.forename: Jani
authors.initials: J
authors.lastname: Tervo
authors.forename: Seppo
authors.initials: S
authors.lastname: Honkanen
authors.forename: Markku
authors.initials: M
authors.lastname: Kuittinen