28 MHz swept source at 1.0 μm for ultrafast quantitative phase imaging

Area of Science:

• Photonics and Optical Engineering
• Biomedical Imaging Technology
• Laser Physics

Background:

• High-throughput optical imaging requires high-speed swept sources, a challenge for current technologies.
• Phase information in imaging necessitates advanced swept source capabilities.
• Existing swept sources struggle to meet the megahertz sweep rate demands.

Purpose of the Study:

• To demonstrate a novel inertia-free swept source (BLISS) for ultrafast optical imaging.
• To achieve a 28 MHz wavelength sweep rate for interferometric imaging at 1.0 μm.
• To showcase the adaptability of BLISS for various imaging modalities.

Main Methods:

• Developed a stable breathing laser as inertia-free swept source (BLISS).
• Incorporated a tunable dispersion compensation element for adjustable sweep range (~10 nm to ~63 nm).
• Utilized a fiber-based laser cavity for robustness and broadband operation.

Main Results:

• Achieved a 28 MHz wavelength sweep rate with good intensity stability (1.6% std/mean).
• Demonstrated excellent wavelength repeatability (<0.05% per sweep) enabling single-shot imaging.
• Applied BLISS to an interferometric time-stretch (iTS) microscope for 1.2 μm lateral resolution imaging.
• Showcased potential for optical coherence tomography (OCT) with axial resolution <12 μm.

Conclusions:

• BLISS is a robust, broadband, inertia-free swept source meeting ultrafast imaging demands.
• The 28 MHz sweep rate and high repeatability enable advanced single-shot imaging.
• BLISS shows significant potential for diverse applications including iTS microscopy and OCT.