在弱物體近似下, 運用傅立葉光學, 從成像系統角度對自聚焦共焦傳感技術進行了理論研究。著重分析了該技術測量樣品縱深結構時圖像的成像機理。由于光纖具有本征場的模式, 對光的振幅和相位的響應是相干的, 從而可用相干傳遞函數(CTF) 描述系統性能。結果表明, 系統相當于一復振幅線平移不變系統, 具有低通特性和層析特性。
關鍵詞: 共焦顯微成像; 相干傳遞函數(CTF) ; 光纖傳感器; 自聚焦透鏡; 光學檢測
Abstract: By Fourier op t ics method, fiber2op t ic confocal senso r using a gradient2index (GR IN ) lens has been analyzed theo ret ically as an imaging system upon the w eak object app roximat ion. The imaging mechanism to measurement dep th st ructure is analysed,w h ich can be described p recisely by a coherence t ransfer funct ion (CTF) , because fiber2op t ic have eigen mode and coherent to the response of op t ical am2 p litude and phase. It has been p roved that the fiber2op t ic confocal senso r system behave as a linear sh ift invariance system, perfo rm s like a lowpass filter and has h igh axial reso lut ion.
Key words: Confocalm icro scopy; Coherent t ransfer funct ion (CTF) ; F iber2op t ic senso r; Gradient index (GR IN ) lens; Op t ical detect ion