RESUMEN
For what we believe to be the first time, digital holographic microscopy is applied to perform optical diffraction tomography of a pollen grain. Transmission phase images with nanometric axial accuracy are numerically reconstructed from holograms acquired for different orientations of the rotating sample; then the three-dimensional refractive index spatial distribution is computed by inverse radon transform. A precision of 0.01 for the refractive index estimation and a spatial resolution in the micrometer range are demonstrated.
Asunto(s)
Holografía/métodos , Imagenología Tridimensional/métodos , Microscopía/métodos , Polen/ultraestructura , Refractometría/métodos , Procesamiento de Señales Asistido por Computador , Tomografía Óptica/métodos , Algoritmos , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodosRESUMEN
We show that digital holography can be combined easily with optical coherence tomography approach. Varying the reference path length is the means used to acquire a series of holograms at different depths, providing after reconstruction images of slices at different depths in the specimen thanks to the short-coherence length of light source. A metallic object, covered by a 150-microm-thick onion cell, is imaged with high resolution. Applications in ophthalmology are shown: structures of the anterior eye, the cornea, and the iris, are studied on enucleated porcine eyes. Tomographic images of the iris border close to the pupil were obtained 165 microm underneath the eye surface.