In this paper we present construction of an optical coherence tomography system capable to measure birefringeant properties of the materials. Radiation in this measuring system propagates in the free space with polarization state preservation. Balanced detection has been used to improve noise properties of a system. Preliminary measurements are presented.
Dispersion of optical elements and sample in optical coherence tomography (OCT) system introduce a wavelength dependent phase distortion to the light beam propagating in OCT system. This causes blurring of the image in high resolution OCT using broadband light sources. Also decreased resolution with the depth of a sample is observed. To avoid this, the overall dispersion of the system can be compensated using a dispersive material in the reference arm of a system. Unfortunately, the dispersion is changed in the system with the probing depth. Overcome to this problem is numerical dispersion compensation technique. Calculations can be made after the measurements have been taken to provide depth dependent compensation. Various techniques and their possibilities are presented.
Optical Coherence Tomography (OCT) is a novel optical measurement technique for high resolution, high sensitivity 2D and 3D visualization of material inner structure. With the aid of OCT one can analyze a wide range of biological and technical materials in non-contact and non-destructive way. In our research we concentrate on possibilities of using OCT systems for characterization of polarization properties of investigated materials. We present a short review of polarization sensitive OCT topologies and principle of polarization state measurement.
The spectral shape of a light source in optical coherence tomography imaging is of prime importance because it determines resolution and quality of the image. Spectra and axial point spread function of photonic crystal fiber light source TB-1550 from Menlosystems GmbH before and after optical spectral shaping are presented. Low-pass and high-pass filters are simulated to shape the irregularities in light spectra of the source. Full-spectrum shaping results with use of spectral processor are calculated. Results show that shaping of a light source improves meaningly axial resolution and inhibits sidelobes of the point spread function.
An Optical Low-Coherence Tomography (OCT) is a novel optical measurement technique, which enables non-destructive and non-contact investigation of multilayer structures. Nowadays, this method is highly applied in medical diagnostics. Despite of great progress in optoelectronics and optical measurement methods there is lack of studies on the OCT for non-medical application. In this paper authors present a laboratory OCT system for surface and subsurface investigation of scattering technical objects such as polymer layers. Preliminary test results on subsurface technical objects investigation using OCT system have been presented and discussed.