Nonlinear conversion in optical waveguide filled with NaNO2

This paper contains the first experimental results of nonlinear conversion in optical waveguide filled with solid nonlinear media. The experimental sample was made from SiO2 fiber of the 1.6 cm length. During the pumping of the sample by the pulse laser, the generation of second harmonic radiation was observed at the whole length of the sample filled with NaNO2. Despite the visibility of this effect, the detected signal was rather weak due to the scattering inside the fiber. Nevertheless, the successful experiment presented in this work may lead to the future development of new nonlinear devices using photonic crystal fiber filled with solid nonlinear medium.