<title>Analysis of gain characteristics of Nd-doped sol-gel-based waveguide amplifier</title>

Abstract

In this paper, we present an analysis of optical amplification properties of Nd-doped planar waveguides on glass substrates fabricated by sol-gel process. Modified gain characteristics are determined from the susceptibility profile and the waveguide dispersion properties. The waveguide dispersion properties are represented by the propagation coefficient variation with optical frequency, /3(w). This is determined by solving the non-linear dispersion equation using the waveguide structural parameters, such as, the transverse refractive index profile, the waveguide film thickness and the operating optical frequency. The susceptibility profile, x(w), is determined using the measured absorption spectra from the fabricated waveguide samples. The analysis is facilitated by fitting an appropriate Gaussian distribution to the measured absorption spectra at the resonant frequency. It is observed that the gain profile is modified asymmetrically by the waveguide parameters.