Different interaction schemes with carbon nanotubes in a pulsed planar waveguide laser

We studied operation characteristics of a Gd³⁺ and Lu³⁺ co-doped Yb:KYW planar waveguide laser, Q-switched by carbon nanotube-based saturable absorbers in two direct interaction and one evanescent-field interaction regimes.

I. Introduction

Waveguide lasers are a new type of lasers where the waveguide functionality is carved directly into optical gain medium. They possess great potential for developing compact pulsed laser sources due to the simple and miniaturized cavity configuration, relatively low pump power, and cost-effective operations [1]. Since the first successive demonstration of a passively -switched solid-state waveguide laser (Nd-glass waveguide laser using an acetate sheet containing organic dyes) [2], many efforts have been devoted to find efficient gain materials, waveguide structures, and novel saturable absorbers (SAs) for pulsed operation. For pulsed waveguide lasers, SAs in the direct and evanescent-field interaction schemes have been previously reported.