Germanate glass core fiber GDF-MM-8/125-98


Higly Ge-doped silica fibers are used for variety of nonlinear applications.

Please see frequently asked questions below.


Article GDF-MM-8/125-98

                                                     Typical loss spectrum            


High germania core fiber 


Core diameter, µm 8 x 7 (elliptical)
Clading diameter, µm 125 ± 1
Coating diameter, µm 260 ± 10
Delta n 0.14
GeO2 concentration, % 98
Cutoff wavelength, µm ~ 0.7
Attenuation  (at 1550nm), dB/km 200
Attenuation  (at 2100nm), dB/km 110
Attenuation  (at 2300nm), dB/km 200
Splicing loss with ordinary fiber, dB ~ 1

Germanate glass core fiber (Article GDF-MM-8/125-98)


What kind of fibers are using to achieve low coupling loss? And how does the fiber compare to standard SMF in terms of softening temperature?

We do not have detailed instructions on the technology of splicing fibers with core of germanate glass with standard silica fibers of the SMF-28 type. By means of trial and error method you have to achieve loss values in the range 0.3-0.8 dB (most of the users of these fibers did it). Maybe you can find some general ideas in papers by Huang (Opt Eng) and Aydin (Opt Exp).



 Compact all-fiber 2.1-2.7 um tunable Raman soliton source based on germania-core fiber

Publication: Vol. 27, No. 20 / 30 September 2019 / Optics Express. Autor: YANHONG LI, TUANJIE DU, BIN XU, HUIYING XU, ZHIPING CAI, VALERY M. MASHINSKY, AND ZHENGQIAN LUO

 2166nm all-fiber short-pulsed Raman laser based on germania-core fiber

Publication: Vol. 27, No. 24 / 25 November 2019 / Optics Express. Autor: TUANJIE DU,YANHONG LI,HONGJIAN WANG,ZHIHAO CHEN,VALERY M. MASHINSKY, AND ZHENGQIAN LUO

 Supercontinuum generation up to 2.7um in the germinate-glass-core and silica-glass-cladding fiber

Publication: Laser Phys. Lett. 9, No. 3, 219-222 (2012). Author: V. A. Kamynin, A. S. Kurkov, V. M. Mashinsky

 Germania-Based Core Optical Fibers

Journal: LIGHTWAVE TECHNOLOGY, VOL. 23, NO. 11, NOVEMBER 2005. Autor: Evgeny M. Dianov, Member, IEEE, and Valery M. Mashinsky

 Germania-glass-core silica-glass-cladding modified chemical-vapor deposition optical fibers: optical losses, photorefractivity, and Raman amplification

Publication: OPTICS LETTERS / Vol. 29, No. 22 / November 15, 2004. Autor: V. M. Mashinsky, V. B. Neustruev, V. V. Dvoyrin, S. A. Vasiliev, O. I. Medvedkov, I. A. Bufetov, A. V. Shubin, A. N. Guryanov, V. F. Khopin, and M. Yu. Salgansky and E. M. Dianov

 Highly doped silica-based fibers for nonlinear applications

Publication: ECOC 2004, Autor: M.M.Bubnov