We present three optical multi-channels spectrometers for the interrogation of label-free biosensors based on different kinds of transducers : resonant nanopillars (RNP), microring resonators (MRR), localized and propagative surface plasmon resonance (LSPR and SPR). Light is collected from the multi-channel biosensors (up to 12-channels) with optical fibers and is remapped to a packed straight line forming the input slit of the spectrometers. The combination of high resolution CMOS sensors and embedded signal processing makes it possible to extract the resonant wavelengths of the transducers with a precision in the range of 1-20 pm depending on the type of transducer. The performance of the three transducer / spectrometer systems has been evaluated in the framework of EU and regional projects for the monitoring of chemical pollutants found in oceanic waters (FP7 - EnviGuard), crop health monitoring (Interreg France-Wallonie-Vlaanderen - SmartBioControl/BioSens) and bioreactor monitoring (EutoTransBio - APTACHIP).
We are reporting on a Multi-Color Laser Engine (MLE) multiplexing four wavelengths (405 nm, 488 nm, 561 nm, 640 nm) by means of a Photonic Integrated Circuit (PIC) with Silicon Nitride (SiN) waveguides. Multiple building blocks are tested that allow manipulating the light in the waveguides to achieve fiber switching and variable optical attenuation. To slow down facet degradation and extend chip lifetime at near Ultra-Violet (UV) wavelengths (405 nm), a lateral endcap is implemented on chip and tested for reliability. Reasonable coupling and on-chip losses have been achieved in view of a practical use of the technology.