Improving the detection limit of conformational analysis by utilizing a dual polarization Vernier cascade

The dual polarization microring technique enables the simultaneous and accurate detection of thickness and refractive index of a bound molecular layer. By using three microring resonators in a double Vernier cascade configuration, the dual polarization technique is improved on three distinct levels: an increase of the sensitivity, a suppression of common noise due to self-referencing and the ability to migrate from a standard tunable laser to a cheap broadband LED and an on-chip arrayed waveguide grating as read-out system, allowing for a system which is orders of magnitude faster and cheaper. A dual polarization Vernier cascade proof-of-concept is fabricated and characterized, a read-out computational framework is constructed and it is shown on a theoretical basis that the limit of detection is improved. (C) 2016 Optical Society of America