Three-dimensional inter-layer optical signal transmission realized by a monolithically integrated semiconductor-based...

Area of Science:

• Photonics
• Optical Engineering
• Materials Science

Background:

• Traditional optical switching faces limitations in miniaturization and speed.
• Three-dimensional photonic integrated circuits (3D-PICs) offer enhanced functionality and density.
• All-optical switching is crucial for overcoming electronic bottlenecks in computing and communication.

Purpose of the Study:

• To propose and demonstrate a new monolithic photonic device for 3D all-optical switching.
• To investigate the ambipolar photo-carrier transport properties of a silicon microrod.
• To achieve efficient inter-layer signal transmission in integrated photonic circuits.

Main Methods:

• Fabrication of a monolithic device integrating a silicon microrod and silicon nitride waveguide/microdisk.
• Measurement of resonant wavelength shifts in the silicon microrod under continuous-wave laser pumping to study carrier transport.
• Utilizing a pump-probe technique with on-chip silicon nitride waveguides for all-optical switching demonstration.

Main Results:

• The ambipolar diffusion length of the silicon microrod was determined to be 0.88 µm.
• Successful demonstration of all-optical switching using the integrated silicon microrod and silicon nitride microdisk.
• Switching time windows of 439 ps (on-resonance) and 87 ps (off-resonance) were achieved.

Conclusions:

• The developed device enables 3D all-optical switching for inter-layer signal transmission.
• The findings highlight the potential of silicon microrods for advanced photonic integrated circuits.
• This technology paves the way for more practical and flexible monolithic 3D-PICs for all-optical computing and communication.