Multi-channel RF-optical receiver enabled by a high performance p-i-n InP-InGaAs-based photodetector array

Area of Science:

• Optoelectronics
• Semiconductor Devices
• Optical Communications

Background:

• Photodetector arrays are crucial for optical communication systems.
• Improving responsivity and efficiency is key for enhanced performance.
• Indium Phosphide (InP) and Indium Gallium Arsenide (InGaAs) are vital materials for photodetector fabrication.

Purpose of the Study:

• To propose and characterize an integrated back-illuminated InP/InGaAs p-i-n photodetector array (PDA).
• To evaluate the PDA's performance metrics including responsivity, quantum efficiency, bandwidth, and bit error rate.
• To explore its potential applications in radio on free-space optical (RoFSO) communications.

Main Methods:

• Fabrication of an integrated back-illuminated InP/InGaAs p-i-n photodetector array.
• Characterization of the PDA's small-signal response and transmission properties.
• Performance evaluation under specific bias voltages and photocurrent levels.

Main Results:

• Achieved high average optical responsivity up to 1 A/W at 1550 nm.
• Reached an external quantum efficiency as high as 81% at -5 V bias.
• Demonstrated a 3 dB bandwidth of 3.6 GHz and a bit error rate below 10^-12 at 2.25 Gbit/s.

Conclusions:

• The developed InP/InGaAs PDA exhibits excellent optoelectronic performance.
• Its compact size and large photosensitive area are suitable for advanced applications.
• The PDA is a promising candidate for future radio on free-space optical (RoFSO) communication systems.