All-fiber acousto-optic frequency shifter excited by focused surface acoustic waves

Area of Science:

• Photonics
• Acousto-optics
• Fiber optics

Background:

• Efficient light coupling between spatial modes is crucial for advanced optical systems.
• Existing methods for mode coupling can be complex or destructive.

Purpose of the Study:

• To present a novel fiber-optic frequency shifter.
• To demonstrate a non-destructive and efficient method for coupling light between two spatial modes.

Main Methods:

• Utilizing acoustic flexural waves to induce coupling in optical fibers.
• Exciting acoustic waves by pressing the fiber against a Lithium Niobate (LiNbO3) substrate.
• Focusing surface acoustic waves using a curved interdigital transducer for efficient excitation.

Main Results:

• Successfully demonstrated light coupling between two spatial modes in a fiber.
• Achieved high efficiency in the frequency shifting process.
• The excitation method was confirmed to be non-destructive.

Conclusions:

• The developed fiber-optic frequency shifter offers a promising solution for optical signal manipulation.
• The acousto-optic coupling technique provides an efficient and non-destructive approach for mode conversion.