自 2011 年介電微球輔助超解析成像被提出以來，其成像機制仍存在高度爭議。過去常以 photonic nanojet、evanescent wave、near-field collection 或 virtual image magnification 等機制解釋解析度提升現象，然而單一機制仍難以完整說明不同微球尺寸、幾何外型與資訊收集條件下所觀察到的成像行為。因此，本研究以有限時域差分法（finite-difference time-domain, FDTD）建立三維數值模型，分別分析 dipole source 系統與 plane wave illumination 系統，探討球形玻璃微球與 dome-shaped 結構在 full information 與 selected information 條件下之成像特性。

本研究以歸一化強度分佈與 visibility 作為主要分析指標，用以評估兩個相鄰 source 或 sample 是否能形成可辨識的 two-peak 成像結果。在 dipole source 系統中，結果顯示無球體條件下兩個 dipole source 的分辨能力主要受波長、dipole 間距與相位差 ϑ影響；加入球形玻璃微球或 dome-shaped 結構後，系統可在特定結構半徑與 ϑ𝐶條件下提升 visibility。相較於 full information，selected information 可在部分條件下得到相近甚至更高的 visibility，表示有助於分辨相鄰 source 的有效相位、干涉與散射資訊可能集中於特定資訊區域，而非均勻分佈於完整場資訊中。

在 plane wave 系統中，本研究進一步分析 sample 寬度、幾何相位差 ϑ𝐼、slant angle 與 polarization angle 對成像結果之影響。結果顯示，無球體條件下即使改變 ϑ𝐼或資訊收集範圍，visibility 仍接近 0，表示兩個相鄰 sample 無法被有效分辨。加入球形玻璃微球後，selected information 可在特定 sample 寬度、結構半徑與 ϑ𝐼 條件下有效提升 visibility。Dome-shaped 結構亦可在 selected information 條件下產生高 visibility，但部分結果會受到 side lobe、ghost image 或局部場強化影響，因此不能僅依據 visibility 數值判定解析能力。

為避免將假性峰值誤判為真正的 two-peak 成像結果，本研究建立 visibility 驗證流程，包含 phase difference 趨勢檢測、單一 source 或 sample 移除測試、gap 依存性測試與 ghost image 判斷。結果顯示，只有當雙峰結構能隨 phase difference 與 gap 呈現合理變化，且峰值能對應至實際 source 或 sample 時，該 visibility 才可視為有效解析結果。此外，slant angle 與 polarization angle 的共同作用可在特定條件下進一步提升 visibility，但同時也可能產生 ghost image，因此仍需搭配驗證流程進行判斷。

綜合而言，本研究結果顯示，介電微球輔助超解析成像並非單純由微球存在、photonic nanojet、evanescent wave 或 full information 收集所決定，而是受到介電結構幾何外型、結構尺寸、sample 尺寸、相位差、入射角、偏振方向與資訊收集範圍共同影響。Selected information 可保留有助於提升 visibility 的有效相位、干涉與散射資訊，並可能是理解介電微球輔助超解析成像機制中過去被忽略的重要因素。本研究結果可作為未來設計高解析度、高效率與低複雜度光學成像系統之參考。

Dielectric microsphere-assisted imaging has attracted considerable attention because it offers a simple and low-cost approach for achieving optical super-resolution beyond the diffraction limit. However, its underlying physical mechanism remains controversial. In this study, finite-difference time-domain (FDTD)simulations were performed to investigate the super-resolution mechanism of dielectric microspheres under both dipole source and plane wave illumination systems. Spherical glass microspheres and dome-shaped dielectric structures were compared under full information and selected information collection conditions. The simulation results show that selected information can produce visibility comparable to or even higher than full information under specific structure sizes, phase difference conditions, and incident field configurations. In particular, dome-shaped structures and selected information can effectively enhance the distinguishability of two adjacent sources or samples, suggesting that super-resolution is not solely determined by collecting complete field information. Instead, the effective phase, interference, and scattering information contained in selected regions may play a critical role. These findings provide a possible explanation for the super-resolution behavior of dielectric microspheres and offer guidance for designing efficient high-resolution optical imaging systems.

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