Terahertz photodiode integration with multi-octave-bandwidth dielectric rod waveguide probe

Area of Science:

• Photonics
• Terahertz (THz) Technology
• Integrated Circuits

Background:

• Photonic integrated circuits are crucial for multi-octave bandwidth terahertz (THz) applications.
• Existing rectangular waveguide (WR) interconnects limit bandwidth to a single octave, hindering THz applications.
• Uni-traveling-carrier photodiodes (UTC-PDs) are key components in THz systems.

Purpose of the Study:

• To develop an ultra-wideband (UWB) interconnect technology for THz photonic integrated circuits.
• To overcome the bandwidth limitations of traditional WR interconnects.
• To enable multi-octave characterization of THz devices.

Main Methods:

• Exploiting UWB near-field coupling between planar waveguides and silicon (Si)-based subwavelength dielectric rod waveguides (DRWs).
• Integrating UTC-PDs with Si DRWs for THz signal transmission.
• Utilizing Si DRWs as probes for device-under-test (DUT) characterization.

Main Results:

• Demonstrated UWB operation from 0.1 THz to 0.4 THz for on-chip integrated UTC-PDs.
• Enabled multi-octave device-under-test characterization of UTC-PDs using a single DRW probe.
• Achieved UWB interconnects for THz applications operating from 0.08-1.03 THz.

Conclusions:

• The proposed UWB interconnect technology using Si DRWs offers a significant advancement over WR-based probes and quasi-optical coupling.
• This technology enables multi-octave bandwidth operation and facilitates on-chip integration of THz circuits.
• The findings pave the way for broader applications of THz technology in areas requiring wide bandwidth.