Time-to-brightness converter (TBC): measuring photon arrival time with conventional cameras

Area of Science:

• Photonics
• Computational Imaging
• Computer Vision

Background:

• Accurate measurement of photon arrival times is crucial for various applications, including time-of-flight (ToF) imaging.
• Existing methods often require specialized equipment or complex calibration procedures.
• Modern complementary metal-oxide semiconductor (CMOS) cameras possess global shutters with finite rise/fall times that can be exploited for timing measurements.

Purpose of the Study:

• To introduce a new, cost-effective method for measuring photon arrival times with sub-nanosecond precision.
• To demonstrate the feasibility of using conventional cameras for high-precision time-of-flight measurements.
• To enable high-resolution three-dimensional (3D) imaging by leveraging pixel-level timing information.

Main Methods:

• The method utilizes two conventional cameras to capture images.
• It exploits the finite rise/fall time characteristics of the electro-optical global shutter in CMOS cameras.
• Photon arrival times are mapped to normalized pixel brightness to determine time of flight.

Main Results:

• Sub-nanosecond precision in measuring photon arrival times was achieved.
• Time-of-flight (ToF) was determined with a precision better than 0.3 nanoseconds.
• The method allows for simultaneous high spatial resolution, enabling high-performing 3D imaging.

Conclusions:

• A novel and practical method for sub-nanosecond photon arrival time measurement using standard cameras has been presented.
• The technique offers a cost-effective alternative for time-of-flight applications and 3D imaging.
• The pixel-level implementation ensures high spatial resolution, paving the way for advanced imaging systems.