Multi-channel delay sampling to extend imaging depth in high-speed swept-source OCT systems.

Area of Science:

• Biomedical Optics
• Optical Imaging
• Signal Processing

Background:

• High-speed swept-source optical coherence tomography (SS-OCT) is crucial for various imaging applications.
• Extending the imaging depth of SS-OCT is a persistent challenge.
• Current methods often involve trade-offs in speed or performance.

Purpose of the Study:

• To introduce a novel multi-channel delay sampling method for SS-OCT.
• To enhance the imaging depth and signal-to-noise ratio (SNR) of SS-OCT systems.
• To achieve extended ranging distance without sacrificing imaging performance.

Main Methods:

• A multi-channel delay sampling technique was implemented using N channels with fixed time delays.
• Interference signals were captured, digitized, and calibrated to compensate for phase shifts.
• Signals were merged in k-space and resampled to linearize the spectrum.

Main Results:

• The sampling rate was increased by a factor of N, extending the ranging distance by N times.
• Signal-to-noise ratio and sensitivity were enhanced within the original depth range.
• The method successfully extended imaging depth without altering k-clock triggering or other performance metrics.

Conclusions:

• The multi-channel delay sampling method effectively extends imaging depth in SS-OCT.
• This technique offers improved SNR and sensitivity, enhancing overall system performance.
• This advancement provides a valuable tool for deeper, higher-quality OCT imaging.