光學應變感測隨機雷射

Abstract

本研究利用可調式閥值隨機雷射來製作高靈敏度可撓曲應變感測器，透過感測器受應力後造成表面散射介質分布改變，使隨機雷射閥值有所不同，本論文使用水熱法成長氧化鋅奈米柱陣列，並使用羅丹明6G(Rhodamin 6G)為增益介質，透過無序的氧化鋅奈米柱散射，R6G出射光子其輻射強度隨著外加脈衝雷射激發能量的改變，主要可分為三種不同光子輻射區間，分別為自發輻射(spontaneous emission)、放大自發輻射(amplified spontaneous emission, ASE)及具同調性(coherent)的隨機雷射輻射。我們進一步地將氧化鋅奈米柱成長於軟性基板;並藉由應力改變樣品曲率，而有效地改變R6G出射光子與氧化鋅奈米柱陣列間的碰撞平均自由路徑(mean free path, MFP)，進而調控該隨機雷射系統的臨界激發閥值。 藉由低溫簡單製成的方式製作光學檢測的應變感測器，比起傳統的應變感測器優越許多，將來可以運用在各個管路、橋梁等監控。We have demonstrated a highly sensitive flexible strain sensor ,the distribution of the surface scattering medium changes after being strain by the sensor,which changes the random laser threshold. In this study, the ZnO nanorods synthesized by the hydrothermal method was randomly distributed on the flexible substrate to serve as optical scattering centers, and the gain material of rhodamin 6G (R6G) was then spin-coated to cover the entire ZnO nanorods. Consequently, by bending different strain on the flexible substrate to select an appropriate mean-free-path (MFP) for the emitted photons interacting with the ZnO nanorods, the tunable random laser can be designed and shows different spectral behaviors.This srtain sensor is superior to traditional,it can be used in various pipelines, bridges and other monitoring.in the future.