Spectrally-sampled OCT for sensitivity improvement from limited optical power

Area of Science:

• Biomedical optics
• Optical imaging
• Coherence tomography

Background:

• High optical illumination power in optical coherence tomography (OCT) improves signal-to-noise ratio but is limited by tissue damage thresholds and autocorrelation signals.
• Existing OCT methods face challenges in enhancing sensitivity without escalating optical power.

Purpose of the Study:

• To introduce a spectrally sampled multi-wavelength light source for OCT systems.
• To improve signal sensitivity and dynamic range in OCT without increasing optical illumination power.

Main Methods:

• A fiber Sagnac comb filter was employed to spectrally sample a continuous spectral light source.
• The spectrally sampled light source was integrated into an OCT system.
• Point spread function analysis was conducted to evaluate system performance.

Main Results:

• The spectrally sampled OCT system demonstrated an approximate 50% improvement in dynamic range compared to conventional continuous spectral light source OCT.
• This enhancement was achieved at the same average optical power of 6 mW.
• The proposed method effectively addresses the limitations of high optical power in OCT.

Conclusions:

• A spectrally sampled multi-wavelength light source is a viable strategy for enhancing OCT sensitivity and dynamic range.
• This technique offers a method to improve OCT performance while adhering to safety limits for biomedical tissues.