Novelty low-cost integrated photonic biosensor using broadband source and on-chip spectral filter

Integrated label-free photonic biosensors provide an excellent limit of detection in combination with a low-cost disposable. Their application has thus far been limited by the necessity of an expensive tunable laser. In this article, we present a novel sensor, eliminating the tunable laser by combining a sensitive Mach-Zehnder interferometer with a broadband light source and an on-chip spectral filter. By curve fitting the original Mach-Zehnder spectrum can be accurately reconstructed from the output of the spectral filter. Bulk sensing experiments yield a limit of detection comparable to conventional integrated photonic biosensors, paving the way for a more widespread range of application.