Zgadzam się
Nasza strona zapisuje niewielkie pliki tekstowe, nazywane ciasteczkami (ang. cookies) na Twoim urządzeniu w celu lepszego dostosowania treści oraz dla celów statystycznych. Możesz wyłączyć możliwość ich zapisu, zmieniając ustawienia Twojej przeglądarki. Korzystanie z naszej strony bez zmiany ustawień oznacza zgodę na przechowywanie cookies w Twoim urządzeniu.
This paper presents a comparison of the spectra of single and cascade of two tilted
fiber Bragg grating (TFBG) sensors. These sensors are characterized by high sensitivity to
the refractive index. The disadvantage of a single TFBG is cross-sensitivity to changes in the
polarization of the light introduced to the sensor, which is visible both when analyzing individual
modes and when analyzing a wide spectral range with global demodulation algorithms. In
response, a cascade structure was created consisting of a set of two TFBGs connected in series
with 90 degrees of mutual rotation between them. This work presents a comparison of the
polarization cross-sensitivity of sensor spectral demodulation algorithms for measuring the
surrounding refractive index (SRI). While maintaining the high accuracy of the SRI measurement
typical of TFBG gratings, a cascade of two such gratings properly oriented toward each other
allows for a significant reduction in the sensitivity of the SRI measurement to polarization changes.
Importantly, the reduction in the polarization cross-sensitivity is significantly greater for the
demodulation methods that determine the cutoff wavelength shift; owing to this, a perpendicular
TFBG(P-TFBG) measurement system without polarization control remains highly reliable. The
application of the proposed P-TFBG system also allows greater SRI sensitivity to be obtained for
a single tilted grating with the same tilt angle.
