title: Chip based common-path optical coherence tomography system with an on-chip microlens and multi-reference suppression algorithm.
abstract: We demonstrate an integrated optical probe including an on-chip microlens for a common-path swept-source optical coherence tomography system. This common-path design uses the end facet of the silicon oxynitride waveguide as the reference plane, thus eliminating the need of a space-consuming and dispersive on-chip loop reference arm, thereby obviating the need for dispersion compensation. The on-chip micro-ball lens eliminates the need of external optical elements for coupling the light between the chip and the sample. The use of this lens leads to a signal enhancement up to 37 dB compared to the chip without a lens. The light source, the common-path arm and the detector are connected by a symmetric Y junction having a wavelength independent splitting ratio (50/50) over a much larger bandwidth than can be obtained with a directional coupler. The signal-to-noise ratio of the system was measured to be 71 dB with 2.6 mW of power on a mirror sample at a distance of 0.3 mm from the waveguide end facet. Cross-sectional OCT images of a layered optical phantom sample are demonstrated with our system. A method, based on an extended Fourier-domain OCT model, for suppressing ghost images caused by additional parasitic reference planes is experimentally demonstrated.
authors.forename: Lantian
authors.initials: L
authors.lastname: Chang
authors.forename: Nicolás
authors.initials: N
authors.lastname: Weiss
authors.forename: Ton G
authors.initials: TG
authors.lastname: van Leeuwen
authors.forename: Markus
authors.initials: M
authors.lastname: Pollnau
authors.forename: René M
authors.initials: RM
authors.lastname: de Ridder
authors.forename: Kerstin
authors.initials: K
authors.lastname: Wörhoff
authors.forename: Vinod
authors.initials: V
authors.lastname: Subramaniam
authors.forename: Johannes S
authors.initials: JS
authors.lastname: Kanger