Exciting fluorescence compounds on an optical fiber's side surface with a liquid core waveguide

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Optical Engineering

Background:

• Fiber optic spectroscopy is crucial for remote and in-situ chemical analysis.
• Excitation uniformity is a key challenge in fiber optic fluorescence detection.
• Liquid core waveguides (LCWs) offer unique light guiding properties.

Purpose of the Study:

• To develop a new fiber optic fluorescence spectroscopic method.
• To utilize a liquid core waveguide (LCW) as an excitation element.
• To achieve efficient and uniform excitation of fluorescence compounds on an optical fiber surface.

Main Methods:

• A laser beam was coupled into a multimode optical fiber.
• The fiber's distal end was inserted into an LCW.
• A tapered optical fiber within the LCW was illuminated, exciting surface-absorbed fluorescence molecules.
• Emitted fluorescence was collected by the tapered fiber and detected via a spectrometer.

Main Results:

• The developed method enables uniform illumination of the tapered fiber surface within the LCW.
• Efficient excitation of fluorescence compounds absorbed on the fiber surface was achieved.
• The technique facilitates sensitive detection of surface-bound fluorescent analytes.

Conclusions:

• The new fiber optic fluorescence spectroscopic method using an LCW is effective for uniform excitation.
• This approach offers an efficient means for detecting fluorescence compounds on optical fiber surfaces.
• The technique has potential applications in various sensing and analytical fields.