Angle-Sensitive Detector Based on Silicon-On-Insulator Photodiode Stacked with Surface Plasmon Antenna

Area of Science:

• Photonics and Optoelectronics
• Nanotechnology
• Semiconductor Devices

Background:

• Angle-sensitive pixels are crucial for advanced optical sensing.
• Surface plasmon antennas offer novel light manipulation capabilities.
• Silicon-on-insulator (SOI) technology provides a robust platform for integrated photonic devices.

Purpose of the Study:

• To design and demonstrate a pixel-level angle-sensitive detector (ASP) using SOI photodiodes and surface plasmon (SP) antennas.
• To investigate the relationship between incident light angle and device response.
• To explore the potential of this ASP for 3D imaging and other applications.

Main Methods:

• Fabrication of SOI photodiodes integrated with gold grating-type SP antennas (1D and 2D).
• Theoretical analysis of the phase-matching condition for light coupling.
• Numerical simulations of absorption efficiency in the SOI layer.
• Experimental measurement of quantum efficiency and angle sensitivity under varying polarization angles.

Main Results:

• Demonstrated successful excitation of surface plasmons in SP antennas, enhancing grating diffraction efficiency.
• Achieved angle discrimination based on the phase-matching condition at specific incident angles.
• 1D gratings showed polarization-sensitive detection, while 2D gratings provided polarization-independent, two-dimensional angle sensitivity.
• Experimental results showed good agreement with theoretical predictions and simulations.

Conclusions:

• The proposed angle-sensitive pixel detector exhibits high quantum efficiency.
• The device enables precise discrimination of incident light angles.
• This technology opens new avenues for 3D imaging, depth-of-field extension, and lensless imaging systems.