Speaker
Description
Silicon photonics provides a scalable platform for fiber optic communication applied to detector readout because it shares the same manufacturing processes and hardening efforts as mature Si CMOS electronics. Single mode fiber links are far superior to multimode fiber optics or electrical cabling, primarily due to the potential for much higher aggregate bandwidth. High spectral efficiency results in large bandwidths enabled by the various degrees of parallelism that are only available in single mode fiber, including wavelength, polarization, and phase multiplexing. Optical multiplexing is especially advantageous compared to electrical multiplexing, as it eliminates the need for rad hard, high-speed circuits for on-detector data concentration, which are a major challenge and a single point of failure.
An overview of Silicon photonic links will be presented, with potential system-level improvements to detector readout chains. Previous results will be highlighted that demonstrate high-speed performance and radiation hardness to high total ionizing dose (TID) levels. A ring resonator modulator (RRM) that was highly doped for improved radiation hardness and low temperature operation was radiation and cryogenically tested. Additionally, a polarization controller and optical receiver was demonstrated to show polarization management, and the potential for bidirectional signaling on a single fiber or a doubling in channel count in unidirectional readout.
Experimental results on a new transmitter PIC will be shown – with 8 λ x 25 Gbps RRMs on the same waveguide, using the same RRM as a previous irradiation result. The wirebonded and fiber attached part has an electro-optic bandwidth of 20 GHz and a total fiber -fiber insertion loss of 6.5 dB. Previous hardness measurements indicate operation at a TID of 1 Grad and temperatures above 77 K.
