collaborators

4 papers

physics.optics2021

Simultaneous microscopic imaging of thickness and refractive index of thin layers by heterodyne interferometric reflectometry (HiRef)

Alexander Nahmad-Rohen, David Regan, Paola Borri +1

The detection of spatial or temporal variations in very thin samples has important applications in the biological sciences. For example, cellular membranes exhibit changes in lipid…

physics.optics2021

Detecting and analysing wavelength-scale optical gradients at an interface by their effects on the internal reflectance near the critical angle

Omar Vázquez-Estrada, Anays Acevedo-Barrera, Alexander Nahmad-Rohen +1

Light's internal reflectivity near a critical angle is very sensitive to the angle of incidence and the optical properties of the external medium near the interface. Novel applicat…

physics.optics2021

An unambiguous derivation of the effective refractive index of biological suspensions and an extension to dense tissue such as blood

Alexander Nahmad-Rohen, Augusto García-Valenzuela

The van de Hulst formula provides an expression for the effective refractive index or effective propagation constant of a suspension of particles of arbitrary shape, size and refra…

physics.optics2019

A model for the complex reflection coefficient of a collection of parallel layers

Alexander Nahmad-Rohen, Wolfgang Langbein

Reflectometry is a technique that uses the light reflected by a sample to determine properties of the sample. Interferometric reflectometry uses interference between two beams, one…