Optical wireless systems for high energy physics: Design and characterization

This paper reports the unique results of a high dose test on an Optical Wireless Communication (OWC) system designed for High Energy Physics (HEP). The 10 Gbit/s optical link under test is composed by a Vertical Cavity Surface Emitting Laser (VCSEL) and a PIN Photo-Diode (PD) with the proper ball lenses. This architecture does not require a complex active tracking due to the system misalignment tolerance of ±3 mm at Bit Error Ratio (BER) of 10-12 and 20 cm distance. The reported OWC system aims at removing the massive wire harness in HEP experiments tracking structures. We experimentally explore the limits of our prototype components under strong radiation conditions, in order to validate the compatibility of HEP experiments. Both VCSEL and PD performance are strongly reduced after 1 h of proton irradiation and the components can tolerate a total fluence of ∼1×1014 p/cm2.