Ultra-low coherence interferometry for determination of refractive index and thickness of transparent film

2000 ◽  
Author(s):  
S. Inoue
Keyword(s):  
Refractive Index ◽  
Transparent Film ◽  
Low Coherence ◽  
Low Coherence Interferometry

scholarly journals Fast Cross-Linking-Characterization of Waveguide-Polymers on Wafers by Imaging Low-Coherence Interferometry

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 1046
Author(s):  
Christopher Taudt ◽  
Bryan Nelsen ◽  
Sandra Schlögl ◽  
Edmund Koch ◽  
Peter Hartmann
Keyword(s):  
Refractive Index ◽  
Cross Linking ◽  
Imaging Spectrometer ◽  
Low Coherence ◽  
Spatially Resolved ◽  
Low Coherence Interferometry ◽  
Novel Method ◽  
Phase Data

This work introduces a novel method to characterize cross-linking differences in spincast polymers for waveguide applications. The method is based on a low-coherence interferometer which utilizes an imaging spectrometer to gather spatially resolved data along a line without the need for scanning. The cross-linking characterization is performed by the determination of the wavelength-dependent optical thickness. In order to do this, an algorithm to analyze the wrapped phase data and extract refractive index information is developed. Finally, the approach is tested on photo-lithographically produced samples with lateral refractive index differences in pitches of 50 μm.

Simultaneous Measurement of Refractive Index and Thickness of Transparent Plates by Low Coherence Interferometry

1997 ◽  
Vol 4 (4) ◽  
pp. 507-515 ◽  
Author(s):  
Masato Ohmi ◽  
Takehisa Shiraishi ◽  
Hideyuki Tajiri ◽  
Masamitsu Haruna
Keyword(s):  
Refractive Index ◽  
Simultaneous Measurement ◽  
Low Coherence ◽  
Low Coherence Interferometry

scholarly journals Spatially Resolved Cross-Linking Characterization by Imaging Low-Coherence Interferometry

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1152 ◽  
Author(s):  
Christopher Taudt ◽  
Bryan Nelsen ◽  
Elisabeth Rossegger ◽  
Sandra Schlögl ◽  
Edmund Koch ◽  
...  
Keyword(s):  
Refractive Index ◽  
Optical Thickness ◽  
Information Acquisition ◽  
Cross Linking ◽  
Imaging Spectrometer ◽  
Low Coherence ◽  
Spatially Resolved ◽  
Low Coherence Interferometry ◽  
Error Estimations ◽  
Phase Data

A method to characterize cross-linking differences in polymers such as waveguide polymers has been developed. The method is based on the scan-free information acquisition utilizing a low-coherence interferometer in conjunction with an imaging spectrometer. By the introduction of a novel analyzing algorithm, the recorded spectral-phase data was interpreted as wavelength-dependent optical thickness which is matchable with the refractive index and therefore with the degree of cross-linking. In the course of this work, the method was described in its hardware and algorithmic implementation as well as in its accuracy. Comparative measurements and error estimations showed an accuracy in the range of 10−6 in terms of the refractive index. Finally, photo-lithographically produced samples with laterally defined cross-linking differences have been characterized. It could be shown, that differences in the optical thickness of ±1.5 μm are distinguishable.

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