An experimental set-up was devised to record the transmission of red and green HeNe lasers through different types of paper. The measured data was compared with data obtained using the Henyey-Greenstein function (often employed in paper optics models to represent the bulk scattering of material samples) and data obtained using an alternative exponentiated cosine function. The comparisons are us...

Accurate and traceable length metrology is employed by laser frequency stabilization. This paper describes a laser frequency stabilization technique as a secondary standard with a fractional frequency stability of 5.2x10(-10) with 2 mW of power, suitable for practical applications. The feedback stabilization is driven by an intrinsic mixed mode signal, caused by nonlinear optical phenomena with...

PURPOSE Angioscotomas are scotomata caused by vessel shadows. Their extent may be influenced by physiological and pharmacologic conditions and disease. In this study, the authors quantified angioscotomas in normal subjects using a fundus perimetry technique with a scanning laser ophthalmoscope. They further investigated the influence of two different wavelengths on scotoma depth. METHODS For ...

As a remarkable orientationally ordered soft-condensed matter system, the smectic-C*(alpha) phase exhibits an incommensurate nanoscale helical pitch of more than four smectic layers. Recent theoretical advances predict the existence of a new phase showing a helical pitch of less than four smectic layers (<16 nm). By applying a novel optical technique to the study of freestanding films with incr...

The three dimensional display of images of moving objects has been a dream for many decades. Ranging from a study of microscopic objects, such as cells, in their natural environment to three dimensional movies, this dream has been realized under certain circumstances. Short recordings of moving objects have been made holo-graphically in silver halide films. But apart from limited sensitivity, t...

A single chord two-color CO2/HeNe (10.6/0.633 μm) heterodyne laser interferometer has been designed to measure the line integral electron density along the mid-plane of the MAST Upgrade tokamak, with a typical error of 1 × 10(18) m(-3) (∼2° phase error) at 4 MHz temporal resolution. To ensure this diagnostic system can be restored from any failures without stopping MAST Upgrade operations, it h...