Bi2Te3/Graphene Heterostructure as the Saturable Absorber for ~1.0 μm Passively Q-switched Solid State Pulsed Laser

Yijian Sun,Houping Xia

doi:10.3390/cryst12020222

Abstract

Due to the tunable nonlinear optical properties of the Bi2Te3/graphene heterostructure, stable solid state pulsed lasers based on the Bi2Te3/graphene saturable absorber have attracted intensive attention. In this work, the Bi2Te3/graphene heterostructure with good nonlinear absorption characteristics was synthesized by a self-assembly solvothermal route, and the optical saturable absorption properties of the saturable absorber were investigated. Owing to the large modulation depth of Bi2Te3 nanosheets and the high thermal conductivity of graphene, the Bi2Te3/graphene heterostructure saturable absorber shown good nonlinear saturable absorber performance and contributed the improved passively Q-switched Yb3+: GdAl3(BO3)4 pulsed laser when compared with that of the pure Bi2Te3 based Yb3+: GdAl3(BO3)4 laser, no matter pulse width or pulse energy. Our work demonstrates that the Bi2Te3/graphene heterostructure was a promising saturable absorber in ~1 μm solid-state pulsed lasers.

Highlights

For realizing pulsed lasers, an effective method is the passively Q-switching technology because of the compactness and simplicity of the cavity structure
All the chemicals used for synthesizing Bi2Te3 nanosheets, Na2TeO3 (0.1 g), BiCl3 (0.095 g), NaOH (0.12 g), and PVP (0.15 g), were added in graphene oxide (5 mg) which was dissolved in 15 mL ethylene glycol
It is clear that the diffractions peaks of Bi2Te3/graphene heterostructure are in good agreement with those of the hexagonal Bi2Te3 phase (JCPDF card No 15-0863), which indicates the successful synthesis of Bi2Te3 nanosheets

Summary

Introduction

An effective method is the passively Q-switching technology because of the compactness and simplicity of the cavity structure. Several kinds of two-dimensional (2D) nanomaterials, including graphene, transition metal dichalcogenides (e.g., MoS2 and WS2), topological insulators (TIs, e.g., Bi2Te3, Sb2Te3, andBi2Se3), and black phosphorus, have been used as SAs in both fiber and solid-state Q-switched lasers [1–7]. Among these 2D nanomaterials SAs, graphene is the most popular one due to its broadband absorption, low nonsaturable loss, high damage threshold, and controllable modulation depth [1,8]. Due to the heavily populated intrinsic defects and low thermal conductivity of Bi2Te3, most of the peak powers and pulse energies based on Bi2Te3 SAs were very low [17,18]

Methods

Results

Conclusion