自聚焦共焦光纖傳感系統(tǒng)的相干傳遞函數(shù)

在弱物體近似下, 運(yùn)用傅立葉光學(xué), 從成像系統(tǒng)角度對(duì)自聚焦共焦傳感技術(shù)進(jìn)行了理論研究。著重分析了該技術(shù)測(cè)量樣品縱深結(jié)構(gòu)時(shí)圖像的成像機(jī)理。由于光纖具有本征場(chǎng)的模式, 對(duì)光的振幅和相位的響應(yīng)是相干的, 從而可用相干傳遞函數(shù)(CTF) 描述系統(tǒng)性能。結(jié)果表明, 系統(tǒng)相當(dāng)于一復(fù)振幅線平移不變系統(tǒng), 具有低通特性和層析特性。
關(guān)鍵詞: 共焦顯微成像; 相干傳遞函數(shù)(CTF) ; 光纖傳感器; 自聚焦透鏡; 光學(xué)檢測(cè)
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