Dual light field and polarization imaging using CMOS diffractive image sensors.

Area of Science:

• Optics and Photonics
• Image Sensing Technology
• Materials Science

Background:

• Traditional imaging systems often require multiple components for advanced imaging techniques like light field and polarization capture.
• Angle sensitive pixels (ASPs) have been developed to capture four-dimensional light fields by diffracting light using integrated metal gratings.
• The polarization properties of these gratings and their combined effect with diffractive imaging have not been fully explored.

Purpose of the Study:

• To present the first integrated CMOS image sensor for simultaneous light field and polarization imaging.
• To characterize the polarization response of angle sensitive pixels (ASPs) with integrated gratings.
• To demonstrate practical applications of this dual-modality imaging sensor.

Main Methods:

• Development of a CMOS image sensor with integrated metal gratings above photodetectors (angle sensitive pixels).
• Characterization of the sensor's response to varying polarization states and angles of incidence.
• Utilizing the sensor for polarization imaging applications, including birefringence imaging and specular reflection identification.

Main Results:

• Demonstrated simultaneous capture of light field and polarization information using a single integrated sensor.
• Quantified the polarization sensitivity and angular response of the angle sensitive pixels.
• Successfully imaged stress-induced birefringence and identified specular reflections in test scenes.

Conclusions:

• The developed CMOS image sensor offers a compact and efficient solution for combined light field and polarization imaging.
• This technology opens new avenues for advanced imaging applications requiring both spatial and polarization information.
• The ability to identify specular reflections can enhance the performance of light field algorithms in complex scenes.