Dergan Lin

Prediction of electric field frequency correlations for randomly scattering slabs in the nondiffusive regime with the scalar Bethe–Salpeter equation

We show that a scalar Bethe-Salpeter equation model captures the measured copolarized electric field frequency correlation magnitude for randomly scattering slabs in the weakly scattering, nondiffusive regime. Consequently, the model could be used to form images of tissue on the millimeter and submillimeter length scale, and for environmental sensing with comparable scatter, as dictated by the optical scattering length in relation to the scattering domain size.

Printed optics: phantoms for quantitative deep tissue fluorescence imaging

Three-dimensional (3D) printing allows for complex or physiologically realistic phantoms, useful, for example, in developing biomedical imaging methods and for calibrating measured data. However, available 3D printing materials provide a limited range of static optical properties. We overcome this limitation with a new method using stereolithography that allows tuning of the printed phantoms optical properties to match that of target tissues, accomplished by printing a mixture of polystyrene microspheres and clear photopolymer resin. We show that Mie theory can be used to design the optical properties, and demonstrate the method by fabricating a mouse phantom and imaging it using fluorescence optical diffusion tomography.

Opportunities for sub-wavelength imaging based on motion in structured illumination

We describe the concept of controlled or natural motion of an object in a spatially varying field as the basis for high resolution coherent optical sensing and imaging. Examples presented are for microscopy with interfering laser beams and speckle formed by scattering from a random medium. Biomedical and environmental applications are presented and resolution issues discussed.

Printed optics: phantoms for quantitative deep tissue fluorescence imaging: publisher's note.

This note points out a number of corrections that were omitted from the published version of the article [Opt. Lett.41, 5230 (2016)OPLEDP0146-959210.1364/OL.41.005230].

Printed Optical Phantoms for Whole Mouse Imaging

We show reconstructed images of realistic phantoms constructed using 3D printing. This approach is versatile, aids in the development of optical imaging methods, and can be used in the calibration of live mouse imaging data.

Solution of the Bethe–Salpeter equation in a nondiffusive random medium having large scatterers

We present a formalism for solving the scalar Bethe–Salpeter equation (BSE) in the nondiffusive regime under the ladder approximation and for an infinite randomly scattering medium having scatterers of size on the order of or larger than the wavelength. We compare the information content in a wave transport model (the BSE) with that in energy-based transport, the Boltzmann transport equation (BTE), in the spatial frequency domain. Our results suggest that when absorption dominates scatter, the intensity Green’s function from a BTE model is similar to the field correlation Green’s function from a BSE solution. When scatter dominates loss, there are significant differences between the BTE and BSE representations, and the BTE solutions appear to be smoothed versions of those from the BSE. Therefore, field correlation measurements, perhaps extracted from intensity correlations over frequency and space, offer significantly more information than a mean-intensity measurement in the weakly scattering and nondiffusive regime. Our work provides a mathematical framework for electric field correlation-based imaging methods based on the BSE that hold promise in, for example, near-surface tissue imaging.