1.45 ps All-solid-state Q-switched mode-locked laser based on new material Bi2Te3/Sb2Te3

Abstract

In this work, the improvement of material properties and the optimization of mode-locked devices are discussed. The lateral heterojunction Bi₂Te₃/Sb₂Te₃ is prepared by a simple solvothermal method to overcome the limitation of traditional single material and improve the nonlinear optics properties. Based on a Bi₂Te₃/Sb₂Te₃ saturable absorber, the stable passive Q-switched mode-locked operation with wavelength of 1064 nm is achieved in Nd: YVO₄ crystal. When the pump power reaches 5.5 W, a Q-switched mode-locked output with a maximum power of 910 mW is obtained, and the corresponding optical–optical conversion efficiency is 16.5 %. The repetition frequency of Q-switched pulse envelopes is 83.81 kHz, the pulse width is 1.8 μs, and the pulse energy is 10.8 μJ. The repetition frequency of the mode-locked pulse in the Q-switched envelope is 312.8 MHz and the pulse width is 1.45 ps. This flexible tunable laser provides high peak power, narrow pulse width, and highly stable laser output, broadening its application prospects in high-performance pulsed lasers.