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.
Photonic Integrated Circuits (PIC) will change the fundamental paradigms for the design of multi-color laser engines for life sciences. Exemplified with flow cytometry (FCM), integrated optical technology for visible wavelengths will be shown to open a new spectrum of possibilities to control flow cell illumination patterns, such as the number of output spots, the spot size, and even complex patterns generated by interferometry. Integration of additional optical functions such as variable optical attenuation, wavelength division multiplexing or fast shutters adds value to the PIC. TOPTICA is demonstrating integration of PICs in present Multi-color Laser Engine (MLE) architectures. Multiple wavelengths (405nm, 488nm, 561nm, 640nm) are coupled free space into the chip, leveraging its beam steering COOLAC (Constant Optical Output Level Auto Calibration) technology for automatic realignment, thus overcoming the need of fiber input delivery. Once in the waveguide, the light can be redirected and shaped to a desired output pattern and pitch, reducing the need of discrete optical components. In this work, we will discuss the implementation of various building blocks in PIC technology for MLEs and analyze the advantages over current macroscopic counterparts.