Photonics/​Optics

A proposed x-ray instrument - a Fourier-transform x-ray microscope - would enable high-resolution imaging of objects with sizes of the order of 20 nm. (This size range is typical of cell organelles.) The instrument would also offer a spectroscopic capability for the sensitive detection and identification of...

AMPERES is a prototype computer program that implements the algorithm, described in the preceding article, for optimizing designs of diffractive optics. Several other programs for designing refractive optics are commercially available, but they offer very limited capabilities with respect to...

An algorithm for optimizing the designs of diffractive optics is based on constrained dynamics and the reciprocity of electromagnetic propagation. This algorithm can contribute to realization of the potential of diffractive optics, which offer capabilities greater than those of refractive...

Sensors based on microscopic optical resonators and arrays of such resonators have been proposed for detecting trace amounts of specific molecules in small gaseous, liquid, and solid samples. In addition to compactness, these sensors would offer ultrahigh sensitivity - in some cases, enough...

The Integrated Optical Design Analyzer (IODA) is a computer program that facilitates multidisciplinary concurrent engineering of highly precise optical instruments. (IODA should not be confused with a multidisciplinary optical-system-analysis program, called "IMOS," that has been reported...

An improved non-planar ring oscillator (NPRO) of the fiber-pigtailed type has been developed. The improvements over prior lasers of this type lie in details of design and construction that are intended to enhance mechanical stability and thereby increase the stability of optical...

The SEASCRAPE computer program estimates the composition, temperature, and pressure of the atmosphere as a function of position by fitting remote-sounding spectroscopic data to a mathematical model of the transfer of radiation through the atmosphere. SEASCRAPE consists of two integrated...

A report presents a study of the efficacy of shot shifting for reducing stitching errors in diffraction gratings made by electron-beam (E-beam) lithography. Stitching errors arise from fabricating a grating as a mosaic of smaller gratings by frequently translating the grating blank....

In 1987 a discovery led to the formal proof that it is possible to use chaotic functions to arrive at a nonprobabilistic and nondeterministic method normal context of the operation of this system, and by using a virtual operational environment, the investigators are manipulating data in eight dimensions, which require a...

A report describes an experimental investigation of effects of thermally induced intermixing of In0.6Ga0.4As and GaAs on the dynamics of photoexcited charge carriers in In0.6Ga0.4As/GaAs quantum dots. The quantum dots (nanometer-size islands of In0.6Ga0.4As surrounded by GaAs) were grown by...

A report describes experiments in which time-averaged and unsteady local variations in the densities of underexpanded supersonic free jets issuing from a choked circular nozzle were measured by laser-induced Rayleigh scattering. This study is part of a continuing effort to understand the...