Joint electromagnetic and ray-tracing simulations for quad-pixel sensor and computational imaging

Area of Science:

• Optics and Photonics
• Image Sensors
• Computational Imaging

Background:

• Dual-pixel autofocus technology, introduced in 2013, is widely adopted in modern cameras and smartphones.
• Advancements in image sensor technology are leading to new pixel architectures for improved autofocus performance.

Purpose of the Study:

• To describe the design of quad-pixel sensors, where each microlens covers 2x2 sub-pixels.
• To present wave optics simulations and analyze sensor performance, focusing on angular response.
• To introduce a hybrid simulation method combining wave optics and ray tracing for physically accurate synthetic image generation.

Main Methods:

• Sensor design and fabrication considerations for quad-pixel architectures.
• Wave optics simulations to evaluate angular response and optical performance.
• Development of a mixed simulation approach integrating wave optics and ray tracing.

Main Results:

• Detailed design specifications for quad-pixel image sensors.
• Simulation results demonstrating the angular response characteristics of the proposed sensors.
• Validation of the mixed simulation technique for generating realistic synthetic images.

Conclusions:

• Quad-pixel sensors offer a promising next step in autofocus technology.
• The proposed mixed simulation method facilitates a co-design process, linking pixel architecture, lens design, and computer vision algorithms.
• Physically accurate synthetic images generated through this method aid in optimizing the entire imaging system.