Mxene/graphene oxide heterojunction as a saturable absorber for passively q‐switched solid‐state pulse lasers

Abstract

Owing to their unique characteristics, two‐dimensional (2‐D) materials and their complexes have become very attractive in photoelectric applications. Two‐dimensional heterojunctions, as novel 2‐D complex materials, have drawn much attention in recent years. Herein, we propose a 2‐D heterojunction composed of MXene (Ti2CTx) materials and graphene oxide (GO), and apply it to an Nd:YAG solid‐state laser as a saturable absorber (SA) for passive Q‐switching. Our results suggest that a nano‐heterojunction between MXene and GO was achieved based on morphological characterization, and the advantages of a broadband response, higher stability in GO, and strong interaction with light waves in MXene could be combined. In the passively Q‐ switched laser study, the single‐pulse energy was measured to be approximately 0.79 μJ when the pump power was 3.72 W, and the corresponding peak power was approximately 7.25 W. In addition, the generation of a stable ultrashort pulse down to 109 ns was demonstrated, which is the narrowest pulse among Q‐switched solid‐state lasers using a 2‐D heterojunction SA. Our work indicates that the MXene–GO nano‐heterojunction could operate as a promising SA for ultrafast systems with ultrahigh pulse energy and ultranarrow pulse duration. We believe that this work opens up a new approach to designing 2‐D heterojunctions and provides insight into the formation of new 2‐D materials with desirable photonic properties.