Graphene q-switched Yb: phosphate glass channel waveguide laser

Abstract

Q-switched lasers can generate high-energy pulses that can have applications in medicine, material processing and defence. Waveguide lasers have several attractive features such as a low laser threshold and a high slope efficiency, provided that the propagation losses are kept low, compactness and mass-producibility. Ion-exchange is a simple and cheap technique to fabricate loss-loss waveguides in glass, with mode-locked operation being demonstrated in ion-exchanged Yb:phosphate glass lasers using a semiconductor saturable absorber mirror (SESAM). Using graphene as a saturable absorber has several key advantages over SESAMs such as a broad wavelength operating range, cost-effectiveness and ease of fabrication. Graphene has previously been used as a saturable absorber to demonstrate Q-switched mode-locking in a femtosecond-written glass waveguide laser and Q-switched operation in a carbon-irradiated Nd:YAG ceramic channel waveguide laser. In this paper we present an ion-exchanged Yb:phosphate glass waveguide laser, Q-switched using a graphene saturable absorber