Optical thickness measurement with multi-wavelength THz interferometry
نویسندگان
چکیده
منابع مشابه
Surface and thickness measurement of a transparent film using wavelength scanning interferometry.
A wavelength scanning interferometer for measuring the surface and thickness of a transparent film has been studied. A halogen light source combined with an acousto-optic tuneable filter is used to generate a sequence of filtered light in a Linnik interferometer, which leads to a sequence of interferograms captured by a CCD camera. When a transparent thin film is measured, the reflection signal...
متن کاملThickness and optical constants measurement of thin film growth with circular heterodyne interferometry
In this article, we report an alternative method for in situ monitoring of the thickness and refractive index of thin film during the growth process. We design a special structure with a thickness-controlled air film to simulate the process of thin film growth. The phase term of the reflected light coming from this multi-layer structure is modulated and has a strong correlation with the thickne...
متن کاملWide band interferometry for thickness measurement.
In this work we present the concept of wide band interferometry as opposed to white-light interferometry to introduce a thickness measurement method that gains precision when the bandwidth is reduced to an adequate compromise in order to avoid the distortions arising from the material dispersion. The use of the widest possible band is a well established dogma when the highest resolution is desi...
متن کاملMulti Wavelength Methods in Holographic Interferometry
Techniques are presented which take advantage of the wavelength dependence of various phenomena in holographic interferometry. Image-plane interferograms illuminated with light containing multiple wavelengths exhibit color dispersion of the fringes. We extract from this dispersion, fullfield information concerning displacement components which are not disclosed by monochromatic illumination. Th...
متن کاملPrecision Length Measurements by Multi-Wavelength Interferometry
Three different applications of multi-wavelength interferometry are reviewed which have been developed at PTB. They demonstrate the high precision achievable by this technique on multiple scales, from absolute geodetic distances up to 10 m, over prismatic bodies, e.g. gauge blocks, in the sub-meter regime, down to the microscopic roughness of surfaces.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Optics and Lasers in Engineering
سال: 2014
ISSN: 0143-8166
DOI: 10.1016/j.optlaseng.2014.04.007