The rapid growth of large language models is placing increasing demands on data centers, where large volumes of data must be transferred efficiently between servers. Optical interconnects are essential for enabling this communication, but as data rates continue to rise, these systems must deliver higher bandwidth while maintaining low latency and energy efficiency. However, integrating electronic and photonic components remains challenging, as conventional approaches often introduce signal loss, limit interconnect density, and restrict scalability.
As reported in Advanced Photonics Nexus, Dr. Wei Chu and colleagues have developed a reconfigurable germanium–silicon photodetector using a low-loss integration strategy based on fan-out wafer-level packaging (FOWLP). This approach enables seamless integration of electronic integrated circuits and photonic integrated circuits on a single platform without the need for traditional wire bonding, reducing parasitic loss and improving signal integrity.
The system uses a dense network of fine metal interconnects, known as a redistribution layer (RDL), to connect components with high precision. This structure supports high interconnect density—exceeding 102 connections per square millimeter—while maintaining a low insertion loss of less than 0.3 dB/mm at 100 GHz. In addition, the use of benzocyclobutene as a low-dielectric insulating material reduces transmission loss and improves thermal stability for reliable high-frequency operation.
