While a significant body of work exists on the utilization of PIC technology for cheap consumables for lab-on-a-chip applications, here we focus on the utilization of visible wavelength PICs in high-value instrumentation. We have presented chip and system-level characterization results for a multi-color laser engine based on a PIC incorporating the required core functionalities. The chip was implemented in the Triplex silicon nitride technology in the framework of the PIX4life pilot line, with layer thicknesses optimized for visible wavelength life-science applications. The demonstrated chip combines variable optical attenuation and multiplexing of four wavelengths covering the entire visible spectrum (405, 488, 561, 640nm) with moderate overall insertion losses (~5dB chip level, ~6.5dB system level) for three of the wavelengths (488, 561, 640 nm). Further work aims to improve both insertion losses and reliability of the 405 nm interfaces. Moreover, after a first demonstration of module assembly, the focus will now move to verifying and guaranteeing the long-term stability of the assembly. In order to leverage the full flexibility afforded by PIC integration, a version of the chip including beam shaping in its output stage for direct free-space coupling into a flow cytometer is also under development.
NSTL
