Linear-wavenumber swept source based on an acousto-optic device for optical coherence tomography

Area of Science:

• Biomedical Optics
• Laser Physics
• Optical Engineering

Background:

• Conventional swept-source optical coherence tomography (SS-OCT) requires data resampling, complicating real-time imaging.
• A linear-wavenumber swept source (k-SS) can eliminate this resampling step, enhancing imaging speed and quality.

Purpose of the Study:

• To introduce and characterize a high-performance linear-wavenumber swept source (k-SS).
• To demonstrate the practical application of the k-SS in SS-OCT systems.

Main Methods:

• An acousto-optic-modulator-based external-cavity laser diode in a Littrow configuration was employed.
• The k-SS was characterized for linearity, scanning range, output power, linewidth, and sweep rate.
• The k-SS was applied to measure sample distribution without k-domain resampling.

Main Results:

• The k-SS demonstrated strong linearity (R² = 0.9998) in the 1.3 µm region.
• Key performance metrics include a 120 nm scanning range, >43 mW output power, ~1.6 nm linewidth, and a 280 Hz sweep rate.
• Successful application in SS-OCT imaging without resampling was achieved.

Conclusions:

• The developed linear k-SS offers high performance suitable for advanced OCT applications.
• This technology has significant potential for improving real-time, high-quality SS-OCT imaging.
• Eliminating k-domain resampling simplifies OCT system processing and enhances efficiency.