線型彩色共焦量測信號橫向交談問題之研究

Research on lateral cross-talk problems of chromatic confocal microscopy

林宗毅(Tsung-Yi Lin)

指導教授 ： 陳亮嘉 ； 林世聰

國立臺北科技大學/機電學院/自動化科技研究所/碩士(2012年)

摘要

本研究提出了線彩色共焦表面輪廓術反摺積演算法解決橫向交談問題。系統結合彩色共焦測量技術，平行光學路徑，反摺積演算法，執行線型量測且具有單點型解析的彩色共焦測量技術，利用自行設計之軸向色散探頭搭配平行光架構，使系統提升光源之使用效率，有效提升量測速度。為了克服橫向交談問題，本研究使用光譜分析儀探討光和波長之間關係，深入分析近場光學的物理現象，共焦成像原理，得到光強資訊可以被視為一個真正的影像和擴散函數的摺積，由於利用光譜分析，可知擴散函數為水平及深度方向擴散，皆會造成光強資訊重疊或位置誤判的可能，所以提出反摺積演算，可減少擴展函數對於原始影像的影響，使深度反應曲線變得較為纖細，更容易正確判斷峰值位置。針對寬頻光譜縮小頻寬範圍至25nm，使用不同點擴散函數處理這種方法可以更有效縮減深度響應曲線的全寬半高值，改善曲線峰值位置的準確性和穩定性。

關鍵字

線型彩色共焦顯微鏡 ； 橫向交談 ； 點擴散函數 ； 反卷積演算 ； 三維形貌量測

並列摘要

In this research, novel deconvolution methodology is proposed to resolve the lateral and axial cross-talk problems encountered in line-scanning chromatic confocal surface profilometry. The strategy integrates chromatic confocal principle, infinitive microscopic optics and deconvolution theory to resolve the entangled cross-talk problem in microscopic confocal measurement, so the measuring resolution can be greatly enhanced from the level of the traditional line-scanning up to the one achieved by generally traditional point-type confocal measurement. To overcome the problem, this research analyzes the physical phenomenon of optical near field using photonic spectrum analyses for establishing relationship between the light expansion and propagation depth, as well as light wavelength. In the confocal image, acquired spectrum intensity can be regarded as the convolution between the ideal signal from objects and the point spread function (PSF) of incident light. By employing spectrum analyses, important calibrated characteristics of the PSF along both of the lateral and depth directions can be carefully established. By using the individual PSF for its corresponding wavelength detected at its matching focal depth, the proposed deconvolution method has been proved effective theoretically and experimentally in greatly minimizing the full width half maximum (FWHM) of the depth response curve by more than 25 times, thus significantly improving the accuracy and repeatability of microscopic surface profilometry.

並列關鍵字

Linear chromatic confocal microscopy ； cross-talk ； point spread function ； deconvolution ； three-dimensional measurements

參考文獻

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