Recently, we have been working in the application of FBG written in special fibers, namely highly birefringent fibers (HiBi). Due to the birefringence, the effective refractive index of the fiber will be different for the two transversal modes of propagation. Therefore, the optical processing function of a FBG will be different for each polarization. This unique property can be used for advanced optical processing or advanced fiber sensing. Different examples include the generation of lasers with multiwavelength operation at orthogonal polarizations, which can be used for different applications such as wavelength converters [10,11,12] or multiwavelength sources. Other applications include the implementation of tuneable optical polarization delay lines for polarization mode dispersion (PMD) compensation [9,6]. The polarization properties of these devices were also used in Optical Code Division Multiplexing systems, allowing the reduction to almost half the parts number while increasing the signal quality . The same approach was used in Radio-over-Fiber systems for the optimization of the signal quality .
 Nogueira, R.N. ; A.T. Teixeira; R. F. Rocha; J. L. Pinto; Patent PT102871 , May , 2004
 Self-pumped all-optical wavelength converter
 Tuneable dispersion compensator
 Tuneable PMD compensator
 Nogueira, R.N. ; A.T. Teixeira; P.S André; R. F. Rocha; J. L. Pinto; Optics Communications , Vol. 262 , No. 1 , pp. 38 - 40 , 2006.
 Nogueira, R.N. ; J. L. Pinto; R. F. Rocha; Microwave and Optical Tech. Letters , Vol. 48 , No. 11 , pp. 2357 – 2359 , 2006 .
 Nogueira, R.N. ; A.T. Teixeira; J. L. Pinto; R. F. Rocha;, IEEE Photonics Technology Letters , Vol. 18 , No. 7 , pp. 841 - 843, 2006.
 Teixeira, A.T.; R.N. Nogueira; P.S André; M. J. N. Lima; R. F. Rocha; IEE Electronics Letters , Vol. 41 , No. 1 , pp. 30 – 32 , 2005
 K. O. Hill, Y. Fufii, D. C. Johnson e B. S. Kawasaki; Appl. Phys. Lett, vol. 32, pp. 647-649, 1978.