Polar coordinate laser pattern generator for fabrication of diffractive optical elements with arbitrary structure.

A precision laser pattern generator for writing arbitrary diffractive elements was developed as an alternative to Cartesian coordinate laser/electron-beam writers. This system allows for the fabrication of concentric continuous-relief and arbitrary binary patterns with minimum feature sizes of less than 0.6 microm and position accuracy of 0.

Special features of Newton-type fringe formation in a diffraction interferometer.

An interferometer with a Fresnel zone plate located in the center of curvature of a concave mirror was studied. Attention was paid to the unique features of the interference field, which has a special point at which the path difference is equal to zero, thereby allowing for the observation of Newton-type fringes in white and quasi-monochromatic light. The conditions necessary for reducing the instrumental error to values less than lambda/20 were determined.

Lensacon.

A diffractive optical element has been synthesized with laser phototechnology. It can transform a point source into a bright caustic (a light line) stretched along the optical axis. The element transforms a spherical wave into a conic and a point source in the object space to a ring structure in the image space.

Laser Doppler velocimeter as an optoelectronic data processing system.

Using Fourier optics, the conditions of the laser Doppler velocimeter (LDV) optimization in relation to the scattering center size, laser parameters, and photoreceiver aperture are found. The measurement errors are estimated for average and instantaneous velocities with regard to the statistics of the scatterers. The compensating scheme, which eliminates a low-frequency component of the signal and laser noise, is described.