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Updated: Feb 1, 2026
08:06
Fabrication of Polymer Microspheres for Optical Resonator and Laser Applications
Published on: June 2, 2017
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A 2 μm single-mode laser based on a femtosecond-laser-modified fluoride microsphere resonator
Optics Letters
|January 30, 2026
Summary
We demonstrate a new method to achieve stable single-mode lasing in microsphere resonators. This technique suppresses unwanted modes, paving the way for advanced integrated photonics and mid-infrared light sources.
Area of Science:
- Photonics and Optical Engineering
- Materials Science
Background:
- Whispering-gallery-mode (WGM) lasers are known for their high quality factors but suffer from multimode limitations.
- Achieving stable single-mode operation is crucial for many applications, including integrated photonics and specialized light sources.
Purpose of the Study:
- To present a novel mode manipulation strategy for microsphere resonators.
- To enable stable single-mode lasing at a specific wavelength with a low threshold.
Main Methods:
- Femtosecond laser-induced local modification of a fluoride microsphere resonator.
- Precise inscription of two symmetric modification regions on the equatorial plane.
- Utilizing nonlinear laser-material interactions to create permanent refractive index changes.
Main Results:
- Successfully suppressed high-order axial modes in the microsphere resonator.
- Achieved stable single-mode lasing at 1918.58 nm.
- Demonstrated a low lasing threshold of 2 mW.
Conclusions:
- The proposed mode manipulation strategy effectively simplifies the resonance spectrum.
- This approach offers a built-in solution to the intrinsic multimode limitations of WGM lasers.
- The technique holds significant potential for applications in integrated photonics and mid-infrared light sources.
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