WDM modulator circuit for high energy physics applications

Particle detectors in High Energy Physics experiments provide huge amounts of data which needs to be transported to the data center. Fiber-optic links provide a highcapacity low-mass solution. Howevem~ the petformance of semiconductor lasers used in such links is shown to degrade by the amount of radiation that is generated when particles with high energy collide. We investigate a wavelength-division multiplexing (WDM,) scheme in which only the semiconductor modulators are in the high radiation environment; and test the modulators for radiation hardness. The InP-based WDM modulator circuits are designed .for fabrication on generic integration platforms. The samples will be irradiated with a 23 Me V proton beam at Karlsruhe Institute of Technology (KIT) up to various doses. Here we discuss the system concept and preliminary measurements of non-irradiated samples that will later be compared with the irradiated samples.