title: Microfluidic channels with ultralow-loss waveguide crossings for various chip-integrated photonic sensors.
abstract: Traditional silicon waveguides are defined by waveguide trenches on either side of the high-index silicon core that leads to fluid leakage orifices for over-layed microfluidic channels. Closing the orifices needs additional fabrication steps which may include oxide deposition and planarization. We experimentally demonstrated a new type of microfluidic channel design with ultralow-loss waveguide crossings (0.00248 dB per crossings). The waveguide crossings and all other on-chip passive-waveguide components are fabricated in one step with no additional planarization steps which eliminates any orifices and leads to leak-free fluid flow. Such designs are applicable in all optical-waveguide-based sensing applications where the analyte must be flowed over the sensor. The new channel design was demonstrated in a L55 photonic crystal sensor operating between 1540 and 1580 nm.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Wang
authors.forename: Hai
authors.initials: H
authors.lastname: Yan
authors.forename: Swapnajit
authors.initials: S
authors.lastname: Chakravarty
authors.forename: Harish
authors.initials: H
authors.lastname: Subbaraman
authors.forename: Xiaochuan
authors.initials: X
authors.lastname: Xu
authors.forename: D L
authors.initials: DL
authors.lastname: Fan
authors.forename: Alan X
authors.initials: AX
authors.lastname: Wang
authors.forename: Ray T
authors.initials: RT
authors.lastname: Chen
mesh_terms: D004129:Dimethylpolysiloxanes; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D017785:Photons
chemical_list: D004129:Dimethylpolysiloxanes; C013830:baysilon