Monitoring the thinning dynamics of soap films by phase shift interferometry. The case of perfluoropolyether surfactants.

An interferometric method to monitor the thinning process of vertical soap films from a water solution of surfactant materials is reported. Raw data maps of optical path difference introduced by the film are obtained by conventional phase shift interferometry. Off-line re-processing of such raw data taking into account the layered structure of soap films leads to an accurate measurement of the geometrical thickness.

Measuring the thickness of soap bubbles with phase-shift interferometry.

A model for the optical path difference introduced by a soap bubble in transmission is described. The model is then used with interferometric data to solve for the fringe order, and to define a procedure to extract the global film thickness in presence of turbulence flows occurring during the drainage process due to gravity. Experimental results on soap bubbles examined in single-pass phase-shift interferometry are presented.

Supercontinuum source tuned by an on-axis monochromator for fluorescence lifetime imaging.

We report on the application of an optically tunable coherent white light source, based on the supercontinuum generation from microstructured optical fibres, to fluorescence lifetime imaging (FLIM) microscopy and Foerster resonance energy transfer (FRET). A prototype lens based on monotonic longitudinal chromatic aberration is used for tuning the supercontinuum wavelengths from 400 to 1000 nm and acts as an axial monochromator, suitable for fibre delivery in confocal microscopy.

Galileo's telescope and the birth of instrumental optics: a review note.

Early steps tracing back to Galileo's telescope and to the birth of instrumental optics are reported. Particulars of lensmaking technology, basic optics laws, concepts of eye and vision, and issues on instrument trade and service are given. Achievements at the roots of our continuing advances in optical sciences are acknowledged.

Long-term deformation at room temperature observed in fused silica.

Cases of long-term deformation of fused silica flats are reported. The phenomenon is detected at the scale of the nanometer, and exhibits a time constant of the order of 9 years. The observed deformation appears related to gravity and constraints, but a change of physical properties locally resulting in non-homothetic behavior is also hypothesized.

Absolute planarity with three-flat test: an iterative approach with Zernike polynomials.

An iterative algorithm to analyze three-flat test data for absolute planarity measurements is presented. Using the properties of Zernike polynomial representations, results are achieved in a fast and effective manner. Details and demonstrative examples are provided.

Three-flat test with plates in horizontal posture.

Measuring flats in the horizontal posture with interferometers is analyzed in detail, taking into account the sag produced by gravity. A mathematical expression of the bending is provided for a plate supported at three unevenly spaced locations along the edge. It is shown that the azimuthal terms of the deformation can be recovered from a three-flat measuring procedure, while the pure radial terms can only be estimated.

Intraocular lenses with surface aspherization: Interferometric study.

Purpose: To accurately evaluate in an optical laboratory 2 different types of intraocular lenses (IOLs).

Setting: Department of Oto-Neuro-Ophthalmological Surgical Sciences and CNR-Institute for Applied Optics, Florence Italy.

Methods: In this study, optical testing facilities based on interferometry were used.

Iterative algorithm for three flat test.

Absolute planarity measurements by interferometry are classically made using three flats, compared two by two in the course of four or more tests. Data reduction is performed with various analytical methods. Here we present instead a data processing algorithm that converges to solution numerically by iteration.

Simple portable lens meter.

A device measuring the optical power of simple lenses by means of moiré phenomena is described. The relevant equations are derived, and a working instrument is presented. A power measuring accuracy better than 0.

Seventeenth-century telescope optics of Torricelli, Divini, and Campani.

Optics of telescope makers Torricelli, Divini, and Campani dating back to the 17th century have been tested interferometrically. It was found that the optical polishing technology had progressed to thorough control over the surface figure and finish, while the nearly paraxial conditions of the aperture remained constant. The instruments that were examined exemplify the knowledge of optics of that time, particularly with respect to the early use of erector units in terrestrial telescopes.