Fiber with frozen-in stress has 84 µm strictly single-mode diameter

Aug. 1, 2009
Researchers at IMRA America (Ann Arbor, MI) have created a single-mode optical fiber with the largest core ever.

Researchers at IMRA America (Ann Arbor, MI) have created a single-mode optical fiber with the largest core ever. The core, with a diameter of 84 µm and an effective mode area (Aeff) of 3600 µm2 at 1 µm, is restricted to single mode due to its low numerical aperture of 0.013 (a refractive-index difference of about 6 × 10-5). Such low numbers were achieved by “freezing in” thermal stress when fabricating the fiber, creating a central parabolic index profile. To do this, the pure-silica fiber preform contained fluorine-doped silica rods in a hexagonal lattice with the central rod missing; the drawn fiber contained, well within the central all-pure-silica region, the stressed portion.

Using the same fabrication method, the researchers created a fiber with an even larger core diameter of 252 µm. While not strictly single-mode, the fiber demonstrated single-mode operation with a mode-field diameter of 149 µm and an Aeff of 17,400 µm2 at 1.03 µm and 31,600 µm2 at 1.5 µm. The output beam from this fiber had a beam quality M2x of 1.04 and M2y of 1.18. Contact Libin Fu at [email protected].

Sponsored Recommendations

Next generation tunable infrared lasers

Nov. 28, 2023
Discussion of more powerful and stable quantum cascade tunable infrared lasers, applications, and test results.

What AI demands mean for data centers

Nov. 28, 2023
The 2023 Photonics-Enabled Cloud Computing Summit assembled by Optica took an aggressive approach to calling out the limitations of today’s current technologies.

SLP feature for lighting control available on cameras offering

Nov. 28, 2023
A proprietary structured light projector (SLP) feature is now available on the company’s camera series, including the ace 2, boost R, ace U, and ace L.

Chroma Customer Spotlight - Dr. David Warshaw, About his Lab

Nov. 27, 2023
David Warshaw, Professor and Chair of Molecular Physiology and Biophysics at the University of Vermont (UVM), walks us through his lab. Learn about his lab’s work with the protein...

Voice your opinion!

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