Vladimir Yu. Venediktov

Noncontact measurement of angular position and angular movement by means of laser goniometer

Abstract. The results of analysis and experimental investigation of a laser goniometer (LG), working in the mode of the noncontact measurement of an object’s angular position, are presented. The important feature of this approach is the very wide range of high-accuracy measurements. In this case, the LG, characterized by the accuracy of ∼0.1 arc sec, has big advantages in comparison to photoelectrical autocollimators which have a rather narrow range of measured angular positions. Our results indicate that the use of a laser dynamic goniometer makes it possible to measure constant angles with an accuracy of 0.05 to 0.1 arc sec in the range of possible angles of 15 to 20 deg. If the measured angle is varying, the residual measurement error contains an additional component, which is equal to ∼0.2 arc sec, induced by the nonflatness of the optical polygon’s faces and by the problems with statistical averaging of the measurement results.

Frequency properties of the confocal ring cavity

Abstract. Passive ring cavities are now treated as the most promising sensitive elements for cheap and technologically simple micro-optical gyros for mass production. Usually the single-mode planar waveguides are considered to be the only possible technology for such devices’ implementation. However, our analysis shows that in some cases the confocal ring cavity, characterized by the degeneration of transverse modes, can be the better alternative for such a device technology. We consider possible advantages and disadvantages of such an approach, its limitations, and technology prospects.

Transformation of Rozhdestvensky Hooks in digital holographic interferometer

The method of amplification of hologram was applied to the so-called Rozhdestvenskiy hooks, that were obtained in the Rozhdestvenskiy interferometer (Michelson interferometer, combined with a grating spectrograph). In such a device the absorption lines reveal themselves as specific “hooks”, whose curvature provides the information about the atomic oscillator force. The holographic amplification “smoothes” the hooks and thus makes their analysis much simpler.

The results of experimental research of adaptive optical system at different wavelengths

The paper presents the first results of investigations of implementation of the closed-loop adaptive optical system at the beamlet segment with the differet length optic path, and reserch operation on different optical wavelengths.

Interference comb-spectroscopy with increasing sensitivity

The wide spectrum from comb - generator of femtosecond laser was applied for illuminating of Michelson interferometer with atomic vapor. The method of holographic interferometry with increasing sensitivity using phase modulator was applied for treatment of digital hologram.

Incoherent holography with the use of Shack-Hartmann wavefront sensor

The paper considers the use of Shack-Hartmann sensor for hologram recording. Despite all the advantages coherent digital holography is limited while fixing ultrafast or short-lived processes, as well as self-luminous objects. The solution to this problem is the use of incoherent digital holography (DIH). It allows to make such observations which is especially important in microscopy. Previously for registration of incoherent digital holograms only schemes based on a Michelson interferometer were used. In this experiment we decided to use Shack–Hartmann sensor to obtain simple pseudo hologram and reconstruct it using electronically-addressed spatial light modulator.

Holographic wavefront sensors: state of the art and prospects

Many areas of optical science and technology require fast and accurate measurement of the radiation wavefront shape. Today there are known a lot of wavefront sensor (WFS) techniques, and their number is growing up. The last years have brought a growing interest in several schematics of WFS, employing the holography principles and holographic optical elements (HOE). Some of these devices are just the improved versions of the standard and most popular Shack-Hartman WFS, while other are based on the intrinsic features of HOE. These are, for instance the modal holographic WFS configurations and some others. The paper presents the review of such techniques.

Microoptical gyros on the base of passive ring cavities

The review paper considers the state-of-the-art in the technique of the small-size optical gyros, based on the use of passive ring-shaped optical cavities (resonators).

On the possibility of phase measurements in microoptical gyro

The paper considers the possibility to organize the phase measurements of the rotation speed in the ring-shaped single mode passive cavity, supplied by lone power divider (directed coupler).

Magnification of interferogram with the use of digital holography

The method of holographic interferometry with the increased sensitivity was applied for measurements of height of nano-steps (from 10 nm and higher) with standard uncertainty about 0.5 nm. The increasing of sensitivity is obtained by interference of waves with mutually complex conjugated phases.