Glass interposer for short reach optical connectivity.

Area of Science:

• Photonics
• Materials Science
• Optoelectronics

Background:

• Silicon photonics offers high integration but faces challenges in chip interconnectivity.
• Efficient and robust interconnections are crucial for advanced photonic integrated circuits.

Purpose of the Study:

• To introduce a novel glass interposer for interconnecting silicon photonic chips.
• To evaluate the performance and alignment tolerance of laser-scribed waveguides within the interposer.

Main Methods:

• Fabrication of a glass interposer using femtosecond laser-scribed waveguides.
• Measurement of insertion loss and coupling efficiency at the interface between the interposer and silicon photonic chips.
• Assessment of coupling degradation with in-plane displacement.

Main Results:

• The glass interposer exhibits an insertion loss of approximately 1.5 dB/cm.
• The interface between the grating coupler and the inscribed glass waveguide shows a low excess loss of ~0.5 dB compared to single-mode fiber coupling.
• The system maintains coupling performance within 3 dB degradation for up to 5 µm of in-plane displacement.

Conclusions:

• Femtosecond laser-scribed waveguides in glass interposers provide a viable solution for silicon photonic chip interconnection.
• The proposed interposer simplifies alignment and demonstrates low optical loss and good displacement tolerance.
• This technology facilitates the development of more complex and efficient silicon photonic systems.