Upconversion imaging using an all-fiber supercontinuum source.

Area of Science:

• Optics and Photonics
• Infrared Imaging Technology
• Nonlinear Optics

Background:

• Mid-infrared (IR) imaging offers unique contrast mechanisms but faces detection challenges.
• Upconversion detection provides a pathway to shift IR signals to visible or near-IR ranges for easier detection.
• Supercontinuum light sources offer broad spectral coverage essential for broadband IR applications.

Purpose of the Study:

• To demonstrate pulsed upconversion imaging utilizing a mid-IR supercontinuum light source.
• To develop a novel mid-IR imaging system with upconversion detection capabilities.
• To assess the imaging performance and resolution of the developed system.

Main Methods:

• Constructed a mid-IR imaging system combining a supercontinuum source (1.8–2.6 μm) with upconversion detection.
• Mixed the mid-IR sample signal with a synchronized 1550 nm laser pulse in a lithium niobate (LiNbO3) crystal.
• Acquired upconverted signals (860–970 nm) using a standard silicon CCD array at 22 frames per second.

Main Results:

• Successfully demonstrated pulsed upconversion imaging with a supercontinuum source.
• Achieved spatial resolution of features as small as 55 μm in the sample plane.
• Validated the capability of the system for high-resolution mid-IR imaging.

Conclusions:

• Pulsed upconversion imaging using supercontinuum light is feasible and effective.
• The developed system offers a promising approach for high-resolution mid-IR imaging applications.
• This technique advances the capabilities of non-destructive imaging and analysis in various scientific fields.