3D topography of trapped micro-particles using Lloyd’s mirror fringe projection method


Parlatan U., Görk G. , İnanç A., İnci M. N. , Ünlü M. B.

SPIE Photonics West 2019, California, Amerika Birleşik Devletleri, 2 - 07 Şubat 2019, cilt.1088159

  • Yayın Türü: Bildiri / Yayınlanmadı
  • Cilt numarası: 1088159
  • Basıldığı Şehir: California
  • Basıldığı Ülke: Amerika Birleşik Devletleri

Özet

The purposed technique enables three-dimensional surface topography of optically trapped micro-particles via projection of the fringe pattern that is manufactured by a fiber optic Lloyd’s mirror assembly. A fiber optic Lloyd's mirror assembly is basically a technique to create an optical interference pattern using the real light point sources and their images. In this application  this assembly is combined with an inverted optical microscope body so that, the projected fringe beam is focused on to the optical path of the interted microscope. The generated fringe pattern thanks to this technique is deformed when it is projected on an object's surface and this deformation is placed right above the objective of the microscope. Fringe positioning, fringe width, and the separation are easily adjusted by modifying the distance between the optical fiber and the mirror and the produced fringes are collected with a set of lenses and projected to the sample surface. The phase analysis of the acquired image is carried out by One Dimensional Continuous Wavelet Transform method. The experimental setup is a simple and low cost to construct and is insensitive to the ambient temperature fluctuations and environmental vibrations that cause unwanted effects on the projected fringe pattern. This basic experimental setup enables a reliable and high precision optical topography measurement method in micro-scale without any high-cost equipment or optical apparatus.

 

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Topics: Optical fiber, Lloyd’s mirror, wavelet transform, fringe analysis, surface topography, object profile, interferometry