2007

We demonstrate a novel method that enables one to measure the structure of highly reflecting fiber Bragg gratings. The method is based on measuring both the transmission and reflection spectra of the grating and applying an inverse-scattering algorithm. The use of the transmission spectrum significantly reduces the sensitivity of the reconstruction to measurement noise, and therefore it significantly decreases the measurement duration. We experimentally demonstrate our method for reconstructing the structure of an apodized grating with a reflectivity of 99.91%. [Read more…]

Fig. 1 Schematic description of experimental setup used for measuring structure of strong FBGs. FBG is the interrogated fiber Bragg grating and M is a mirror. The intensity transmission spectrum and the interference spectrum between a reflection from the grating and a reference signal, obtained by using a mirror, are measured.

Anatoly Sherman, Amir Rosenthal, and Moshe Horowitz, “Extracting the structure of highly reflecting fiber Bragg gratings by measuring both the transmission and the reflection spectra,” Opt. Lett. 32, 457-459 (2007)

We demonstrate experimentally, for the first time to our knowledge, a reconstruction of a highly reflecting fiber Bragg grating from its complex reflection spectrum by using a regularization algorithm. The regularization method is based on correcting the measured reflection spectrum at the Bragg zone frequencies and enables the reconstruction of the grating profile using the integral-layer-peeling algorithm. A grating with an approximately uniform profile and with a maximum reflectivity of 99.98% was accurately reconstructed by measuring only its complex reflection spectrum. [Read more…]

Image Description: Fig. 1 Intensity of the measured complex reflection spectrum.

Amir Rosenthal, Moshe Horowitz, Sven Kieckbusch, and Ernst Brinkmeyer, “Experimental reconstruction of a highly reflecting fiber Bragg grating by using spectral regularization and inverse scattering,” J. Opt. Soc. Am. A 24, 3284-3288 (2007)