Fiber-based polymer microtips produce Bessel-like beams

March 1, 2019
Polymer microtips can be formed in a straightforward process on the end of single-mode fibers, enabling the production of Bessel-like light beams for particle guiding and other uses.

With their nondiffracting and self-healing properties, Bessel-like beams find use in particle guiding, microprocessing, and other applications. Forming axicon lenses on the ends of optical fibers offers a compact way to generate Bessel-like beams without the alignment and stability issues that arise with bulky optical systems. However, previous fiber-based microaxicons produced Bessel-like beams with only several concentric rings (less than five, and with low quality), and other fiber-based methods produce the beams either with low quality or with narrow wavelength range. Now, researchers at Fudan University (Shanghai, China) have developed a novel and efficient approach to generating Bessel-like beams by fabricating self-growing polymer microtips at the facet of single-mode fibers. The method promises an effective, low-cost, convenient, and ultracompact method for generation of Bessel-like beams.

First, a dose-reduction photopolymer droplet is deposited at a precise location on the facet of a fiber to fabricate the creation of a short microtip with optimized shape. The fiber-based microtips can then be tailored by green laser power (of on the order of a microwatt) coupled into the other end of the fiber, laser exposure time (on the order of a minute), and diffused oxygen concentration, enabling all-fiber, high-quality Bessel-like beam conversion. Distributing oxygen in the convex droplet inhibits polymerization when the irradiated laser power is low and can naturally polish the end of the microtip to form a microaxicon. The resulting microtip functions over a broad bandwidth and produces Bessel-like beams with a maximum of more than 30 concentric rings. The researchers verified the self-healing properties of the beams. Reference: J. Tan, R. Yu, and L. Xiao, Opt. Lett. (2019); https://doi.org/10.1364/ol.44.001007.

About the Author

John Wallace | Senior Technical Editor (1998-2022)

John Wallace was with Laser Focus World for nearly 25 years, retiring in late June 2022. He obtained a bachelor's degree in mechanical engineering and physics at Rutgers University and a master's in optical engineering at the University of Rochester. Before becoming an editor, John worked as an engineer at RCA, Exxon, Eastman Kodak, and GCA Corporation.

Sponsored Recommendations

March 31, 2025
Enhance your remote sensing capabilities with Chroma's precision-engineered optical filters, designed for applications such as environmental monitoring, geospatial mapping, and...
March 31, 2025
Designed for compatibility with a wide range of systems, Chroma's UV filters are engineered to feature high transmission, superior out-of-band blocking, steep edge transitions...
March 31, 2025
Discover strategies to balance component performance and system design, reducing development time and costs while maximizing efficiency.
March 31, 2025
Explore the essential role of optical filters in enhancing Raman spectroscopy measurements including the various filter types and their applications in improving signal-to-noise...

Voice your opinion!

To join the conversation, and become an exclusive member of Laser Focus World, create an account today!