Application of the Digital Holographic Interference Microscopy for Thin Transparent Films Investigation

Abstract

In this work the digital holographic interference microscope (DHIM) is proposed for investigation of thin transparent films on transparent substrates. The DHIM allows 3D imaging of surfaces of thin transparent films, and measurement of their geometrical parameters (thicknesses, sizes of defects). The method of the holographic interferometry, and the optical layout of the DHIM are described. The experimental results of investigation of thin AlN coatings on acryl substrates are presented.

Combining the polarization-contrast and interference-contrast methods for three-dimensional visualization of anisotropic microobjects

“…The first digital holographic interference microscope (DHIM), which makes it possible in real time to obtain three-dimensional images of phase microobjects and to measure their geometrical parameters, was used to investigate the three-dimensional morphology of erythrocytes and thin films. [3][4][5][6][7][8][9][10] Among phase microobjects, those that possess the property of anisotropy and that change the polarization state of the radiation transmitted through them constitute a special group. The polarization-contrast method is used to study such microobjects in optical microscopy, making it possible to obtain the images of microobjects with higher quality and resolution than is achieved in the phase-contrast and interference-contrast methods.…”

Quantitative coating thickness determination using a coefficient-independent hyperspectral scattering model

“…Point measurement techniques include destructive sampling and inspection under a microscope, ultrasonic techniques based on pulse-echo ultrasonics [1], spectroscopic ellipsometry and low-coherence interferometry [2]. Field measurement techniques include digital holographic techniques [3], spectral reflectance optical coherence tomography [4,5] and other scanning probe setups. The point measurement techniques provide limited spatial information and the field techniques are typically slow and introduce challenges in scanning and automation.…”