Lohja, Finland  August 25, 2006 – LIEKKI expands its broad product line of highly doped fibers, optical engines (OEs) and simulation software with the offering of custom preform manufacturing services.

LIEKKI’s Direct Nanoparticle Deposition (DND) process provides single step deposition of extremely highly doped core preforms. DND’s nanoparticles also mitigate the onset of clustering and related effects such as photodarkening in ytterbium fibers. Unlike conventional solution doping techniques, DND rapidly directly deposits waveguiding and doping materials simultaneously in a single step. It is particularly effective for large mode area (large core) fibers requiring flat refractive index profiles and/or radially doped profiles. Also, large core/clad ratio preforms can be realized cost effectively. Conventional processes require many complicated, time consuming steps in particular for large mode area and large core/clad ratio preforms.
 

In addition to conventional round preforms, LIEKKI’s flexible glassworks technology allows for manufacturing of other non-circular shapes, such as rectangular preforms. “We have recently upgraded our manufacturing facility which has resulted in our preform manufacturing process offering significant performance advantages and lower costs when comparing to conventional processes. We offered our services on a limited basis and had great success. We felt that it was time to offer our preform services more broadly. We continue to offer the highest performance fibers in the industry. Preform supply allows us to leverage additional volume in our facility”, says Mr. William Willson, LIEKKI’s Vice President Marketing and Sales.
 

Pic. 1: DND process: Close up of a preform in the flame
 

“We are currently producing erbium and ytterbium doped preforms with aluminosilicate glass host that show the industry’s highest concentrations of RE-ion (e.g. 15 000ppm wt Yb2O3) while maintaining excellent optical properties. These core rods are now available to customers with core-to-cladding dimensions in range 1:5 - 1:20”, says Mikko Söderlund, Product Manager for Fibers. “We are open to custom designs like extreme core-to-clad ratios, other dopants or combinations like Nd or Er:Yb codoping as well as other glass hosts such as phosphosilicate”, Mr. Söderlund continues.

Each preform is delivered fully characterized with refractive index profile and absorption data.

Pic. 2: Glasswork process: Production of complex preforms

Pic. 3: Typical RIP of a ytterbium preform