The authors previously found that measurements of precorneal tear film thickness in animals, using laser interferometry and confocal microscopy, were larger than earlier estimates. They proposed that this occurred because optical methods did not disturb film structure and measured full thickness, including mucus. In the present study, tear film thickness was measured in humans. Coherent light w...

A common problem when profiling surfaces with steps or discontinuities using white-light (coherence-probe) interferometry is localized spikes (batwings) or spurious peaks due to diffraction effects. We show that errors due to these effects can be minimized by processing the irradiance data obtained with an achromatic phase-shifter operating on the geometric (Pancharatnam) phase to yield the val...

The frequency-dependent group delay of dielectric mirrors was measured by spectrally resolved white-light interferometry. Chirped mirrors and thin-film Gires-Tournois interferometers designed for dispersion control in a femtosecond Ti:sapphire laser oscillator-amplifier system were tested with a group-delay resolution of +/-0.2 fs and a spectral resolution of ~1 nm over the spectral range of 67...

The pulse width of hard undulator radiation (32 ps width, energy 14 keV) was determined by intensity interferometry. The method, in combination with various x-ray monochromators, enables measurements to be taken over a wide range of time frames, from ns to fs. The applicable target includes measurements of ultrafast x-ray pulse widths from fourth generation synchrotron light sources.

We report a dramatic improvement of the spatial coherence and beam divergence (0.66 mrad) of a 13.2 nm wavelength Ni-like Cd tabletop laser by injection seeding the soft x-ray laser amplifier with high-harmonics pulses generated in a Ne gas jet. This phase coherent laser is an attractive light source for at-wavelength interferometry of extreme ultraviolet lithography optics and other applications.