光學相位共軛技術在散射介質中的優化分析

Abstract

將光在介質中聚焦是一大挑戰，因為當光經過散射介質時，會產生散射，所以本篇利用光學相位共軛(Optic phase conjugation, OPC)技術，來克服此困難，並使用時域擬譜法(pseudospectral time-domain, PSTD)來模擬 OPC，因為它能夠精準且有效地模擬大尺寸的範圍。當 OPC span為 360°時，是最理想的回聚效果，但這對於應用極其不便，所以本篇會分別模擬相位共軛鏡(phase conjugate mirror, PCM)的中心點在X軸與Y軸且OPC span為30°、90°與150°，並探討不同介質密度時，對於回聚的影響與變化。藉由以上分析，我們察覺 PCM 的中心點在 X 軸有較好的回聚效果，且 OPC span 為 90°時為良好回聚的最小角度，能更加優化的應用器材，並拓展非侵入性治療技術的開發。

Optical phase conjugation (OPC) is a promising solution to overcome optical distortion caused by scattering effects in nonhomogeneous media. Through utilizing the pseudospectral time-domain (PSTD), the OPC can be efficiently and effectively simulated in large scale domain. While OPC span of 360 provides the most ideal refocusing effect, collecting the whole angle of propagating light is impractical for real world applications. Consequently, this study simulates the center points of the phase conjugate mirror (PCM) along both the X-axis and Y-axis, with OPC spans of 30°, 90°, and 150°, while manipulating the number density of the medium. The results indicate that PCM center point along the X-axis exhibits superior refocusing effects. Additionally, an OPC span of 90° represents the optimal minimum angle for effective refocusing. The application of this technology holds the potential to advance non-invasive biomedical techniques and achieve more precise therapeutic methods.