Opportunity
Current optical or photo-acoustic imaging systems often require multi-wavelength laser sources to enable functional imaging, such as measuring oxygen saturation (sO₂) or blood flow. Traditional methods for generating multi-wavelength laser pulses involve complex optical setups with numerous free-space optical components (e.g., mirrors, lenses, beam splitters) and multiple free-space-to-fiber couplings. These configurations are inherently unstable due to sensitivity to environmental perturbations like temperature changes or airflow, leading to coupling efficiency degradation and requiring frequent recalibration. Additionally, such systems are bulky, difficult to deploy, and costly to maintain. The need for a compact, stable, and efficient multi-wavelength laser source motivates the development of this patent, which leverages optical fibers to simplify the system while improving performance and portability.
Technology
The patent introduces an optical radiation modulation device that uses parallel optical fibers to convert a single-wavelength input (e.g., 532 nm laser) into multi-wavelength outputs via stimulated Raman scattering (SRS). Key innovations include:
- Fiber-Based Modulation: The device employs multiple optical fibers arranged in parallel, where at least one fiber modulates the input wavelength into multiple Stokes wavelengths (e.g., 545 nm, 558 nm) through SRS, while others may pass the original wavelength unchanged.
- Time-Delay Integration: By varying the optical path lengths of the fibers, the device generates temporally spaced pulses, enabling time-domain multiplexing of multi-wavelength signals.
- Reduced Free-Space Couplings: Unlike conventional systems, this design minimizes free-space optical elements, relying instead on fiber couplers for beam splitting and combining. This enhances stability, reduces alignment complexity, and improves portability.
- Scalability: The modular design supports flexible configurations (e.g., 2–5 fibers) to tailor wavelength outputs for applications like photoacoustic microscopy (PAM), optical coherence tomography (OCT), or fluorescence imaging.
Advantages
- Enhanced Stability: Fewer free-space components reduce sensitivity to environmental perturbations.
- Simplified Deployment: Compact, fiber-centric design improves portability and ease of use.
- Cost-Effective: Eliminates the need for expensive optical alignment systems and frequent maintenance.
- High Efficiency: Stimulated Raman scattering in fibers ensures rapid wavelength conversion with minimal energy loss.
- Versatility: Configurable for various imaging modalities (e.g., PAM, OCT) by adjusting fiber parameters.
Applications
- Photo-acoustic Microscopy (PAM): Enables high-resolution, multi-wavelength imaging for functional studies (e.g., sO₂ mapping).
- Optical Coherence Tomography (OCT): Provides broadband light sources for depth-resolved tissue imaging.
- Laser Scanning Fluorescence Microscopy: Delivers precise wavelength combinations for multiplexed fluorescence imaging.
- Biomedical Probes: Compact fiber-optic probes for minimally invasive diagnostics.
