Time-resolved propagation of polarized light in turbid media: experiment and theory

This paper presents our study of time-resolved propagation of polarized light in scattering media. Monte Carlo simulated time-resolved Stokes vectors of transmitted light were compared with the experimental results. A satisfying match has been obtained

Polarization-gated imaging techniques based on time-resolved Stokes vectors for filament tissues

We report the discovery of using various time-resolved Stokes vector components for more efficient imaging of filament tissues. In particular, the Stokes vector components S2 and S3 were found more useful, compared with the other two components. The time-resolved Stokes vectors of signals transmitting chicken breast tissue, mouse cardiac muscle tissue, and polystyrene micro-sphere solution are compared. A target of chicken bone in chicken breast tissue is used for demonstrating the effectiveness of various Stokes vector components for imaging purpose. Also, Monte Carlo simulations were conducted for comparison

Study of polarization evolution in phantom tissues with ultrafast optics techniques: Monte Carlo simulations and experiments

This paper presents our study results of polarized short pulse transmission through phantom tissues made of polystyrene particle solutions with various concentrations and particle sizes. To improve the quality of optical imaging using an ultrafast light source, study is required to fully understand the evolution of the polarization state in the sample, as well as the time- and polarization-dependent distributions of optical intensity exiting from samples. Temporal profiles of the Stokes vectors and the degree of polarization are measured experimentally. The results agree well with those resulting from Monte Carlo simulations. Analyses based on the Stokes-Mueller formalism show that the first scattering event determines the spatial patterns of the transmitted Stokes vectors. When a detected area at the output surface of the sample is symmetric about the incident beam, the temporal profile of transmittance is independent of the incident polarization state. The linear relationship between the average order of scatters and the light propagation time can be used to explain the exponential decay of the degree of polarization and the inversely proportional relationship between the FWHM of the degree of polarization and the scatterer concentration

Polarization-gated imaging techniques based on time-resolved Stokes vectors for filament tissues

We report the discovery of using various time-resolved Stokes vector components for more efficient imaging of filament tissues. In particular, the Stokes vector components S2 and S3 were found more useful, compared with the other two components. The time-resolved Stokes vectors of signals transmitting chicken breast tissue, mouse cardiac muscle tissue, and polystyrene micro-sphere solution are compared. A target of chicken bone in chicken breast tissue is used for demonstrating the effectiveness of various Stokes vector components for imaging purpose. Also, Monte Carlo simulations were conducted for comparison

Void Structures in Regularly Patterned ZnO Nanorods Grown with the Hydrothermal Method

The void structures and related optical properties after thermal annealing with ambient oxygen in regularly patterned ZnO nanrorod (NR) arrays grown with the hydrothermal method are studied. In increasing the thermal annealing temperature, void distribution starts from the bottom and extends to the top of an NR in the vertical (c-axis) growth region. When the annealing temperature is higher than 400°C, void distribution spreads into the lateral (m-axis) growth region. Photoluminescence measurement shows that the ZnO band-edge emission, in contrast to defect emission in the yellow-red range, is the strongest under the n-ZnO NR process conditions of 0.003 M in Ga-doping concentration and 300°C in thermal annealing temperature with ambient oxygen. Energy dispersive X-ray spectroscopy data indicate that the concentration of hydroxyl groups in the vertical growth region is significantly higher than that in the lateral growth region. During thermal annealing, hydroxyl groups are desorbed from the NR leaving anion vacancies for reacting with cation vacancies to form voids

Emission Characteristics of Organic Light-Emitting Diodes and Organic Thin-Films with Planar and Corrugated Structures

In this paper, we review the emission characteristics from organic light-emitting diodes (OLEDs) and organic molecular thin films with planar and corrugated structures. In a planar thin film structure, light emission from OLEDs was strongly influenced by the interference effect. With suitable design of microcavity structure and layer thicknesses adjustment, optical characteristics can be engineered to achieve high optical intensity, suitable emission wavelength, and broad viewing angles. To increase the extraction efficiency from OLEDs and organic thin-films, corrugated structure with micro- and nano-scale were applied. Microstructures can effectively redirects the waveguiding light in the substrate outside the device. For nanostructures, it is also possible to couple out the organic and plasmonic modes, not only the substrate mode