Quantum optical tomography based on time-resolved and mode-selective single-photon detection by femtosecond...

Area of Science:

• Biomedical Optics
• Neuroimaging
• Photonics

Background:

• Optical imaging techniques are crucial for non-invasive biological specimen analysis.
• Existing methods face limitations in sensitivity, resolution, or radiation levels.
• Advanced photon detection is key to improving tomographic imaging capabilities.

Purpose of the Study:

• To develop an optical time-of-flight measurement system for high-resolution mouse brain tomographic imaging.
• To utilize a time-resolved and mode-selective up-conversion single-photon detector for enhanced sensitivity.
• To enable non-contact, non-invasive 3D structural imaging with minimal optical irradiation.

Main Methods:

• Utilized a 100-femtosecond mode-locked fiber laser at 1556 nm to generate probe and pump pulses.
• Employed 4f systems for spectral carving of pulses, separated by 30 nm.
• Integrated a time-resolved and mode-selective up-conversion single-photon detector for data acquisition.

Main Results:

• Achieved a sensitivity of 111 dB, comparable to shot-noise-limited optical coherence tomography.
• Obtained an axial resolution of 57 μm with 380 femtosecond pulses.
• Demonstrated imaging with ultraweak optical irradiation (1.5 mW probe, 30 μW pump).

Conclusions:

• The developed optical time-of-flight system offers high performance for biological imaging.
• This technique provides a new avenue for non-invasive 3D structural imaging of specimens.
• The system's sensitivity and resolution pave the way for advanced neuroimaging applications.