Wavelength-switchable Multiwavelength Erbium-doped Fiber Laser Based on a D-shaped Fiber with a Photoresist Thin-film Overlay

Abstract

A wavelength-switchable multiwavelength erbium-doped fiber (EDF) laser based on a D-shaped fiber with a photoresist (PR) thin-film overlay is proposed and experimentally demonstrated. The D-shaped fiber with a PR thin-film overlay is implemented as a multichannel filter. Based on the evanescent field coupling between the D-shaped fiber and the PR thin-film overlay, periodic transmission characteristics are obtained. The wavelength spacing of the D-shaped fiber with the PR thin-film overlay is controlled by changing the thickness and the refractive index of