Influence of Internal Stresses in Few-Mode Fiber on the Thermal Characteristics of Regenerated Gratings

Abstract

The pre-treatment of few-mode fibers (FMFs) has been successfully done with CO₂ laser. The wavelength difference, Δλ between the two resonant wavelengths in the few-mode fiber Bragg grating (FMFBG) varies with temperature increment during the annealing process. The results show that the treated fibers with lower stresses have lower thermal sensitivity in Δλ than that of non-treated fiber. However, the treated fibers produce FMFBGs with better thermal durability and regeneration ratio. It is conceived that the presence of those stresses in the pristine fiber is responsible for the high thermal sensitivity in Δλ. The thermal relaxation of stresses and structural rearrangement during the thermal annealing process are responsible for the degradation of the strength and resilience of the regenerated grating.

Keywords

Regenerated fiber Bragg grating / few-mode fiber / thermal stress relaxation / CO₂ laser annealing / thermal resilience

References

[1] Hsiao T. C., Hsieh T. S., Chen Y. C., Huang S. C., Chiang C. C.. Metal-coated fiber Bragg grating for dynamic temperature sensor. Optik, 2016, 127(22): 10740-10745.

[2] Li Y. L., Yang K., Li X. W.. Temperature sensing characteristics of metal coated FBG during dynamic cooling process. Optical Fiber Technology, 2018, 45, 368-375.

[3] Gunawardena D. S., Lai M. H., Lim K. S., Malekmohammadi A., Ahmad H.. Fabrication of thermal enduring FBG sensor based on thermal induced reversible effect. Sensors and Actuators A: Physical, 2016, 242, 111-115.

[4] Canning J., Stevenson M., Bandyopadhyay S., Cook K.. Extreme silica optical fibre gratings. Sensors, 2008, 8(10): 6448-6452.

[5] Mihailov S. J.. Fiber Bragg grating sensors for harsh environments. Sensors, 2012, 12(2): 1898-1918.

[6] Fokine M.. Formation of thermally stable chemical composition gratings in optical fibers. Journal of the Optical Society of America B, 2002, 19(8): 1759-1765.

[7] Zhang B., Kahrizi M.. High-temperature resistance fiber Bragg grating. IEEE Sensors Journal, 2007, 7(4): 586-591.

[8] Bandyopadhyay S., Canning J., Stevenson M., Cook K.. Ultrahigh-temperature regenerated gratings in boron-codoped germanosilicate optical fiber using 193 nm. Optics Letters, 2008, 33(16): 1917-1919.

[9] Yang H. Z., Qiao X. G., Das S., Paul M. C.. Thermal regenerated grating operation at temperatures up to 1400–using new class of multimaterial glass-based photosensitive fiber. Optics Letters, 2014, 39(22): 6438-6441.

[10] Nazal N. A. M., Lim K. S., Zaini M. K. A., Yang H. Z., Ahmad H.. Formation of enhanced regenerated grating in few-mode fiber by CO2 laser pretreatment. Applied Optics, 2017, 56(36): 9882-9887.

[11] Li A., Al Amin A., Chen X., Shieh W.. Transmission of 107 Gb/s mode and polarization multiplexed CO-OFDM signal over a two-mode fiber. Optics Express, 2011, 19(9): 8808-8814.

[12] Li A., Al Amin A., Chen X., Chen S., Gao G., Shieh W.. Reception of dual-spatial-mode CO-OFDM signal over a two-mode fiber. Journal of Lightwave Technology, 2012, 30(4): 634-640.

[13] Koebele C., Salsi M., Sperti D., Tran P., Brindel P., Mardoyan H., . Two mode transmission at 2–100Gb/s, over 40 km-long prototype few-mode fiber, using LCOS-based programmable mode multiplexer and demultiplexer. Optics Express, 2011, 19(17): 16593-16600.

[14] Kim B. Y.. Few-mode fiber devices. Optical Fiber Sensors, 1988, 2, 1-463.

[15] Li A., Wang Y., Hu Q., Shieh W.. Few-mode fiber based optical sensors. Optics Express, 2015, 23(2): 1139-1150.

[16] Nazal N. A. M., Lai M. H., Lim K. S., Gunawardena D. S., Chong W. Y., Yang H. Z., . Demarcation energy properties of regenerated fiber Bragg grating sensors in few-mode fibers. Optics Applicata, 2018, 48(2): 263-271.

[17] Chu P., Sammut R.. Analytical method for calculation of stresses and material birefringence in polarization-maintaining optical fiber. Journal of Lightwave Technology, 1984, 2(5): 650-662.

[18] Lim K. S., Zhou Y. H., Chong W. Y., Ken C. Y., Lim C. H., Ali N. M., . Axial contraction in etched optical fiber due to internal stress reduction. Optics Express, 2013, 21(3): 2551-2562.

[19] Zaini M. K. A., Lee Y. S., Lim K. S., Nazal N. A. M., Zohari M. H., Ahmad H.. Axial stress profiling for few-mode fiber Bragg grating based on resonant wavelength shifts during etching process. Journal of the Optical Society of America B, 2017, 34(9): 1894-1898.

[20] Mizunami T., Djambova T. V., Niiho T., Gupta S.. Bragg gratings in multimode and few-mode optical fibers. Journal of Lightwave Technology, 2000, 18(2): 230-235.

[21] Ganziy D., Jespersen O., Woyessa G., Rose B., Bang O.. Dynamic gate algorithm for multimode fiber Bragg grating sensor systems. Applied Optics, 2015, 54(18): 5657-5661.

[22] Lai M. H., Lim K. S., Gunawardena D. S., Yang H. Z.. Thermal stress modification in regenerated fiber Bragg grating via manipulation of glass transition temperature based on CO2-laser annealing. Optics Letters, 2015, 40(5): 748-751.

[23] Shin I. H., Kim B. H., Veetil S. P., Han W. T., Kim D. Y.. Residual stress relaxation in cleaved fibers. Optics Communications, 2008, 281(1): 75-79.

[24] Kim B. H., Park Y., Ahn T. J., Kim D., Lee B. H., Chung Y., . Residual stress relaxation in the core of optical fiber by CO2 laser irradiation. Optics Letters, 2001, 26(21): 1657-1659.

[25] Bucaro J. A., Dardy H. D.. High-temperature Brillouin scattering in fused quartz. Journal of Applied Physics, 1974, 45(12): 5324-5329.