Conventional polarization-sensitive optical coherence tomography (PS-OCT) can provide depth-resolved Stokes parameter measurements of light reflected from turbid media. A new algorithm, which takes into account changes in optical axis, is introduced to give depth-resolved birefringence and differential optical axis orientation images using fiber-based PS-OCT. Quaternion, a convenient mathematical tool, is used to represent an optical element and simplify the algorithm. Experimental results with beef tendon and rabbit tendon and muscle show that this technique has promising potential for imaging the birefringent structure of multiple-layer samples with varying optical axes.
We present a phase-resolved optical Doppler tomography (ODT) sys tem at 1310 nm using frequency domain method. Frequency domain phase-resolved ODT potentially allows for an increased longitudinal imaging range, signal-to-noise ratio and imaging acquisition rates, which can dramatically increase the measurable velocity dynamic range. A detailed derivation of phase-resolved frequency domain ODT and a measurement of flow through micro channel are presented. This technique can be used to quantify flow in integrated microfluidic devices in which complex three-dimensional structures and a wide velocity range are present.
Phase-resolved Optical Doppler Tomography (ODT), an imaging technique based on low coherence interferometry, is presented as a tool to quantify the micro flow in microfluidic channel. Experiments using phase-resolved ODT to image and quantify Electroosmotic Flow (EOF) within a single microchannel are described demonstrating its utility in determining EOF in microchannels. Since it provides cross-sectional imaging of flow velocity, complex flow dynamics caused by microscale effects, such as electrokinetic flow, can be investigated and quantified using this tool.
This paper proposes a calibration system consisting of three components: a quasi-linear intrinsic calibrator, a linear extrinsic calibrator and a nonlinear L-M optimizer. The focal length is evaluated form vanishing points. Then the rotation matrix and the translation vector are estimated linearly. At last a Levenberg-Marquardt optimization is performed to refine the extrinsic parameters by minimizing the reprojection error. The parameterization of the rotation matrix is discussed in detail, and two parameterization methods, Euler-Angle and Axis-Angle are compared. Experimental results prove that the system can calibrate the cameras precisely.