A review of the evolution of the concept of motion over the centuries, starting from the Aristotelian 'prime' philosophy, through modern times is given. The emphasis, however, is placed on the Copernican revolution, Newtonian mechanics/dynamics, Mach and Lange's ideas.

This lecture consists of three parts. In the first, a brief history of the measurements of the light velocity is outlined. In the second part the phenomenon of the superluminal propagation of light pulses in the dispersive and absorbing media is discussed. Finally, the QED effects that influence the velocity of light in vacuum in the presence of the magnetic field are reported in the third part.

We review the modern techniques to control the motion of neutral particles with laser light. Applications of the new capabilities to trap and manipulate particles in a wide variety of scientific problems are presented.

The review of novel solid state lasers for coherent optical velocimetry is presented. The paper is focused on laser diodes as well as diode pumped lasers as the most prospective sources nowadays and in the future in this area of applications. The single frequency diode pumped lasers are discussed in detail. The novel concepts in velocimetry such as chirped lasers, two frequency lasers, and lasers with self-mixing effect are presented. The applications of solid state lasers to Doppler velocimetry, holographic methods in velocimetry, and coherent laser radars are discussed.

The Nd:YAG and Nd:YVO₄ crystals have been used as active media for single-frequency lasers. A thin metal film absorbing selector was used for single-frequency operation and fast tuning in the intermode range. The cavity optical length was variable in 10 - 60 mm range resulting in the frequency chirp of 1 - 6 GHz range.

Single frequency generation output with energy level about 1 mJ in electro-optically Q- switched Nd:YVO₄ laser pumped by 1 cm quasi-cw laser diode bar is demonstrated. Above 170 kW peak power in 5.6 ns pulse duration was achieved. The low threshold, near diffraction limited output, short cavity length advantage is the Nd:YVO₄ laser for low energy, high pulse power in coherent velocimetry, range finding and Doppler radar applications.

Investigations of spectroscopic properties of yttrium-aluminum garnet Y₃Al₅O₁₂ (YAG) doped with Ce, Pr, Nd, Sm, Eu, Ho, Er, Tm, Yb ions and Nd:YAP, Nd:SrLaGa₃O₇, Nd:SrLaAlO₄, Nd:YVO₄, Nd:LiYF₄, Nd:PbMoO₄, Nd:LGS, Nd:GGG, Nd:SVAP monocrystals have been realized. Absorption spectra of the monocrystals in the range 200 nm - 20 micrometer and the luminescence spectra in the range 200 - 800 nm for Pr:YAG, Pr:YAP and Pr:SrLaGa₃O₇ were determined. Except for Pr:YAG, Sm:YAG, Eu:YAG and Pr,Yb:YAG in all other materials an appearance of strong absorption bands in the range of 780 - 840 nm has been stated that enabled us to carry out an efficiency analysis of selective pumping with the use of GaAlAs laser diodes.

In this report comparative analysis of technical characteristics of He-Ne lasers (lambda) equals 0.63 mcm with waveguided resonator the amplifying medium of which is exited by direct current discharge or (HF) SHF field is being carried out. Technical characteristics and results of the designing-technological refinement of the pumping generator, laser waveguide and of the laser as a whole are listed there.

Features and parameters of acousto-optic (a-o) frequency shifters and a-o Bragg cell for spectrum analyzer, developed and manufactured, are shown in this work. Three particularly interesting versions of frequency shifter have been made, using Ge single crystal with LiNbO₃ transducer for (lambda) equals 10.6 micrometer. They were equipped with specially electric matching circuits in order to widen and shape frequency characteristic.

The current state of the optical metrology based on the Doppler effect has been reviewed. Some historical and scientific information is given, in addition the contemporary optical methods of the velocity measurement using the Doppler effect are analyzed. The Doppler effect applications in astrophysics, plasma physics, investigations of gas and liquid flows, acoustics, mechanics of the deforming solid body and of the rotational motion are considered. The description is presented for the following techniques of the velocity measurement: laser Doppler anemometry, laser Doppler vibrometry, laser gyroscopy.

Laser Doppler velocimetry, time-of-flight velocimetry, Doppler rotametry, and time-of-flight rotametry are analyzed. The analysis is based on a simplified scheme where only the detector setup is modified. Various measuring setups are described and their advantages and drawbacks discussed.

Analytical expressions for the crosscovariance (time-of-flight velocimeter, LTV) and for the power spectrum (laser Doppler velocimeter, LDV) are presented based on the assumption of all apertures having a Gaussian transmission function. The objects are simulated at solid targets having lateral spatial correlation, i.e. giving rise to partially developed speckle. The case of fully developed speckle can thus be simulated by having zero correlation length. For both systems and either target the relative width of the crosscovariance (LTV) and power spectrum (LDV) is calculated analytically based on the entire optical system and expressed as a function of the number of modes in the detection system. It is shown that the LTV will give in general a lower variance for the velocity estimate but that spatial correlations of the target are most detrimental to the LTV system. Besides, the decorrelation effects for measurement on curved surfaces are considered and it is shown that both systems will suffer equally in the case of a multimode system but the LTV system will be superior to an LDV system in case of a single mode system. The basic difference between the performance of the two systems stems from the inherent difference in bandwidth.

In the present paper we discuss the implementation of two methods of signal validation for analysis: the amplitude trigger and the spectral trigger. In the first method after validation of the signal with the amplitude trigger the temporary spectrum with the Gaussian window centered on the peak amplitude point is computed with the use of the fast Fourier transform (FFT). The spectrum averaging procedure is applied to improve the signal-to-noise ratio (SNR) value. In the second method the validation trigger is based on analysis of the SNR level obtained from the spectrum computed from a short record (64 or 128 points). In this case the SNR value is defined as the ratio of the peak of the power spectrum of the signal to mean noise power. After validation the spectrum of a 1024-sample record is computed with the use of the FFT and the averaging procedure is performed in the next step. Both methods were verified on simulated data as well as real DS samples taken from experiment.

A number of promising trends are exceptional in present-day optical diagnostics of kinematic and structural parameters of flows. They are: laser anemometry with adaptive temporal and spatial-temporal selection of the velocity vector, measurement of particle sizes by the method of photomixing direct and inverted optical signals, method of optical frequency discrimination in the laser Doppler anemometry (LDA), colored real-time visualization of the fields of optical density in gaseous and condensed media based on polichromatic Foucault-Hilbert transformation, and semiconductor laser anemometry. All of them are the basis for creating a new generation of optical measurement systems to be applied in scientific investigation and industry.

The temporal coherence of the scattered light is analyzed in the case of a point aperture, as well as in the Fraunhofer region of an aperture which is placed in front of a uniformly moving nonabsorbing random phase screen illuminated by a quasimonochromatic plane wave. It is shown that the temporal coherence of the scattered light is affected by not only the motion of the phase screen but also the statistical properties of the random phase screen. Moreover, the coherence of the scattered light in the frequency domain is considered in the case of a polychromatic plane wave. Theoretical considerations are made with a particular emphasis on the evaluation of the spectral changes of the scattered light occurring on its free space propagation from the phase screen to its far zone. It is shown that the spectral changes affected by both the motion of the random phase screen and its statistical properties are present. Both strongly and weakly scattering phase screens are considered. Analytic or closed-form expressions for both the temporal coherence and the spectrum of the scattered light are obtained, and numerical examples are presented.

Electrohydrodynamic (EHD) convection in thin cells filled by dielectric liquids is considered. First, a brief review of practical applications of the cells is presented, which includes liquid pumps, dynamic light scattering and electrochemiluminescence (ECL) displays. In the ECL devices EHD streams play the main role in ion transport, increasing current density more than 1000 times. ECL permits us to observe the shapes of EHD streams while correlation between electrical and optical kinetic characteristics gives information to the conclusion about the structure and velocities of the streams. A physical model is proposed to explain obtained dependencies and experimental results are compared with theoretical ones.

The main purpose of this review is to present the statistical properties of dynamic speckle produced by a diffuse object that moves with a constant velocity and the velocimetry applications that result from these properties. In this way the space-time correlation function of the speckle intensity variation is examined. Two typical speckle motions: boiling and translation are identified and discussed for various optical configurations in the diffraction and image fields in the case of the in plane object motion. The following measurement methods for the diffuse object velocity are introduced: the autocorrelation method, cross-correlation method, spatial filtering method, and zero-crossing method. There are several versions of the above mentioned methods. Special attention is paid to those which allow us to measure both the magnitude and direction of the velocity. In the vast majority of methods the Gaussian illuminating beam is used. In this review the TEM₁₀ illuminating beam is also taken into consideration. Then the autocorrelation methods of velocity measurement for the case of longitudinal motion are presented. It is shown that for this particular case the moving object need not to be a diffuse one, it can be a reflecting object as well. Possibility of the measurement of velocity which is arbitrarily directed with respect to the axis of the illuminating beam is also discussed. The speckle velocimetry methods in which the velocity is determined by means of a direct tracking and recording of the translating speckle generated by the moving object are mentioned. Finally some measurement systems in which laser speckles are used to evaluate subcutaneous flow of liquids are presented. Such systems were found useful in food conservation and medicine.

The space-time correlation functions of amplitude and intensity fluctuations are derived for a dynamic speckle generated by a flat diffuse object illuminated with a TEM₁₀ Hermite- Gaussian laser mode. The object is assumed to move in a plane with a constant velocity. The considerations are limited to the free propagation geometry. The speckle complex amplitude is assumed to obey circular Gaussian statistics. It is shown that intensity fluctuation is a space- time stationary process and its correlation function derived for both near and far diffraction fields depends on the angle which forms the vector of velocity and one of the axes of symmetry of the TEM₁₀ laser mode. This enables the simultaneous measurement of the direction and the magnitude of the object velocity. The velocimetry formulae are derived for a boiling far field speckle detected with a single point detector or with a circularly symmetric soft Gaussian aperture.

A method for measurement of rotational speed and torsional vibrations for semireflective targets is presented. The method is parallel to time-of-flight velocimetry in that a delay time between the passage of a speckle pattern between two detectors is tracked. In this setup the delay corresponds to the passage of scattering structures positioned angularly on the target, here a cylindrical shaft. This is facilitated by observing the subjective speckles in the Fourier plane with respect to the object. The method is proven independently of the location of the object, as well as independently of the diameter of the object. Further, the signal strength is considerably higher than compared with previous laser-based noncontact systems. An implementation is presented and the specifications are given. Tracking of the time delay giving the maximum crosscovariance between the two signals is facilitated by a delay locked loop based on a one-bit digitization of the two input signals.

Two new applications of the photorefractive phenomenon to optical velocimetry are described. One of them concerns the laser Doppler velocimetry with photorefractive two-wave mixing. The second application is covered by the particle image velocimetry, where a photorefractive crystal volume and a set of light sheets are used, respectively, for sampling the flow field in depth instantaneously and for illuminating the fluid volume sealed by small particles.

Optical methods for measuring size and velocity of quasi-spherical biological particles are proposed. This is a holographic continuous exposure method for studying the dynamical and structure characteristics of the Brownian motion of unicellular algae. The measured algae velocity and size distribution functions are reported.

Inertial measurement unit test results in initial orientation measurement mode (in azimuth plane) are presented in this paper. Inertial measurement unit configuration and processing algorithm providing selfcorrection of such gyro errors as instability of zero shift, drift and scale factor are presented. Error selfcorrection is based on using continuous one-directional rotation of the inertial measurement unit about one axis which is parallel (for this inertial measurement unit) to its mounted plane. In this case, errors with correlation time much more than inertial measurement unit rotation period have low effect on measurement accuracy and can be easily corrected. This makes inertial measurement unit invariable to a great extent to gyro errors. Influence of the above mentioned gyro errors on azimuth measurement accuracy up to 3 arcmin was not discovered. Potential to increase azimuth measurement accuracy is shown. Though, test results were obtained for the inertial measurement unit employing low accuracy ring laser gyros, the fiber-optic and integrated-optic gyros are more beneficial for such technology.

The results of studies on the construction of double-channel gyroscope provided for ground navigation are presented. These works have been carried out in the Department of Technical Application of Physics, Institute of Technical Physics, Military University of Technology. The results of simulation based on the Jones's matrix formalism, as well as a usable model description, are included. It is a prototype of the double-channel fiber optic gyroscope DGS-13 based on standard single-mode optic fiber with passive polarization control. The sensitivity of the described system is order of 1 deg/h, while its drift is about 5 deg/h. The upper measurement range is 400 deg/s for the linearity of readings of 500 ppm.

We have investigated the mechanism that determines backscattering light from mirrors and diaphragms influence on intensity and frequency difference of the traveling-wave in ring laser. It is shown, that the connection of the counter waves has diffractional as well as interferention nature and is defined by parameters of the resonator mirrors and diaphragms as well as by their disposition as to the amplifying medium. Using the latter, the methods and the devices that allow us to decrease the influence of the static zone of the waves locking in on the output characteristics in 10 - 20 times have been created. The microprocessor systems for laser gyroscope generation regime support and stabilizing its parameters during exploitation were fulfilled. It is shown experimentally that a laser gyroscope with such systems has a null drift 0.005 degree/hour and a random walk 0.003 degree/sqrt (hour).

This paper presents a description of construction and the technical characteristics of new fiber optic rate gyros VG914, VG910, VG949.

The spatio-temporal Fourier transform is usually applied to determine the velocity of an object from a series of standard light intensity frames. In this paper the technique is extended to also determine the object acceleration. Although this technique is useful in standard illumination conditions, we have applied it to experimental low-light-level images, which require a shorter processing time.

With the new approach described here, the two tangential velocity components needed are acquired separately using the principle of optical heterodyne interferometry, and combined to provide rotational information after having been converted into electrical signals. Due to the heterodyning with the unshifted reference beam, this provides an optical amplification of each measurement beam, and thus significantly increases the optical sensitivity of the system.

Described is an optoelectronic system that makes it possible to measure the position and velocity of a ship model. It operates over a 200 m by 200 m area with a fundamental error less than 0.1 m and consists of an optoelectronic transmitter aboard the model and two stations ashore which are connected to a computer. The ground stations measure angles between a base and the mobile transmitter. Based on the angle data the position and velocity are calculated by the computer. The simultaneous measurements of two models are also possible.

Stress factors can be visualized reliably by measurements of motion dynamics. Spatial portraits and temporal diagrams of impulses from two different kinds of cells -- Physarum and Dictyostelium discoideum -- are considered in the present work. Large numbers of biological applications require development of quantitative measurements in the dimensional range of classical optics. In order to apply this, we used a 3D RM 600 AUTOFOCUS Profilometer with spatial resolution of 1 micrometer². It allows measurement at the dynamical bands of 0.001 - 120 Hz. Perspectives and measured results as well as applications of another computer-aided microscopical technique are discussed.