E.V. Kotmyshev – Design Engineer, 

JSC «SRI «Ekran» (Samara)

E-mail: invest@niiekran.ru

The important part of designing an analog microwave-photonic link operating as part of the modern radio equipment, is accounting the features of the laying of the optical fiber and the possible signal distortion associated with this. For some applications, such as timing distribution, phase distortion is a critical parameter. One source of phase distortion is temperature change. The range of negative temperatures is of particular interest since, due to the difference in the linear expansion coefficients of quartz and the polymer shell, the quartz fiber core will undergo a compressive force. At the same time, the installation density of modern equipment may require the use of very small bending radii. Standard fiber type SMF-28 is not suitable for laying with small radii. For such tasks, the industry has developed special fibers that comply with ITU-T G.657. Another way to reduce losses in macrobends is to use optical radiation sources with a shorter wavelength, for example, 1310 nm. The phase-temperature characteristics of standard optical fibers of the SMF-28 type have been repeatedly discussed in publications. However, in the literature there is no information on the phasetemperature characteristic of fibers resistant to macrobending at a wavelength of optical radiation of the O-band. This article presents the experimental phase-temperature characteristics of Corning's single-mode optical fibers: ClearCurve ZBL and SMF-28 Ultra in the temperature range from minus 60 to + 25 degrees Celsius at an optical wavelength of 1310 nm at a modulation signal frequency of 10 GHz. As the study showed, the phase-temperature characteristic of the ClearCurve ZBL bending-resistant optical fiber is almost completely identical to the phase-temperature characteristic of the SMF-28 Ultra fiber. Consequently, ClearCurve ZBL fiber can be used inside electronic equipment blocks in those places where the required bending radii of the fiber do not allow the use of «standard» fibers. The obtained experimental dependences can be used in the development of fiber-optic transmission lines operating as part of radio-electronic equipment intended for operation in conditions with negative ambient temperature.

1. Urik V.D., MakKinni D.D., Villyams K.D. Osnovy mikrovolnovoi fotoniki: Per. s angl. Pod red. S.F. Boeva, A.S. Sigova. M.: Tekhnosfera. 2016. 376 s. (in Russian)
2. Bakhvalova T.N., Belkin M.E., Emelyanov A.A., Toporkov N.V., Masnoi V.A. Fazotemperaturnye kharakteristiki opticheskikh volokon i kabelei pri raspredelenii opornykh radiosignalov po volokonno-opticheskoi linii. Radiotekhnika. 2017. № 10. S. 184−188. (in Russian)
3. Corning, Inc. White Paper. «An Overview of Macrobending and Microbending of Optical Fibers». 2010.  URL = https://www.corning.com/media/worldwide/coc/documents/Fiber/RC-%20White%20Papers/WP-General/WP1212_12-10.pdf.
4. Opticheskoe volokno Corning ClearCurveZBL. Opisanie izdeliya. URL = https://www.corning.com/media/worldwide/coc/documents/Fiber/PI1464_7-14_rus.pdf  (data obrashcheniya 06.09.2019). (in Russian)