Hybrid III-V/SOI resonant cavity enhanced photodetector

Area of Science:

• Optoelectronics
• Integrated Photonics
• Semiconductor Devices

Background:

• Resonant-cavity-enhanced photodetectors (RCE-PDs) are crucial for high-performance optical communication systems.
• Existing RCE-PDs often face challenges in achieving high efficiency, narrow linewidth, and compact integration.
• Hybrid integration of III-V materials with silicon photonics offers a promising route to overcome these limitations.

Purpose of the Study:

• To propose and investigate a novel hybrid III-V/SOI RCE-PD structure.
• To achieve high quantum efficiency and narrow detection linewidth for wavelength division multiplexing (WDM) applications.
• To demonstrate the feasibility of fabricating and characterizing such a device for silicon-integrated photonics.

Main Methods:

• Proposed a hybrid III-V/SOI RCE-PD structure featuring a high-contrast grating (HCG) reflector and a hybrid grating (HG) reflector with integrated light-absorbing material.
• Conducted numerical investigations to predict device performance, including quantum efficiency and detection linewidth.
• Fabricated a hybrid RCE-PD sample via heterogeneous integration of InP-based material onto a silicon-on-insulator (SOI) wafer and performed experimental characterization.

Main Results:

• Numerical simulations predicted a quantum efficiency close to 100% and a detection linewidth of approximately 1 nm.
• Experimental characterization confirmed a clear enhancement in photo-current at the designed wavelength, validating the HG reflector's field enhancement capability.
• The fabricated device demonstrates the potential for compact vertical cavity design and efficient light absorption.

Conclusions:

• The proposed hybrid III-V/SOI RCE-PD structure is effective in achieving high performance for WDM applications.
• The heterogeneous integration approach enables the realization of compact and efficient RCE-PDs on silicon platforms.
• The study highlights the potential for wavelength tunability during fabrication and the development of silicon-integrated bidirectional transceivers.