The current technical set-up of speckle interferometry is based on temporal phase-shifting with a single CCD camera, which requires a vibrationisolated environment. In order to apply the phase-shifting technique to an industrial environment, without any vibration isolation, four phase-shifted speckle images are simultaneously acquired by means of four cameras. In order to achieve this aim we use four parallel speckle interferometers. The appropriate phase differences between the beams are realized by variable path differences employing movable prisms. This new laboratory set-up demonstrates the feasibility and the applicability of long-range surface structure, surface deformation and surface profile measurements. The change of surface structure, caused e. g. by erosion, influences the fringe contrast of the interference fringes and their visibility of the phase-shifting method. An additional modelling of the quadruple speckle interferometer using a ray tracing simulation program demonstrates the dependence of the fringe contrast on surface structure modifications in the nanometer scale. The ray tracing method takes into account the effects of polarization, diffraction and interference. Measurement results verify the detectability of eroded surface areas.

This paper describes a shearing interferometer with four diffraction gratings for dividing light waves. It allows us to use an extended white light source. This feature of the interferometer is discussed and demonstrated by experiments. By constructing the interferometer for testing transparent object, phase distribution of the light wave passing through an optical lens is measured with a halogen lamp source. By modifying it for the reflecting object, profile of a curved mirror is measured.

Developments in the field of fibre optics and lasers in recent years have had a very major impact upon the creation of fibre optic-based sensor systems, used for a variety of measurement and instrumentation applications. This paper will review some of the most relevant of these recent developments and discuss the prospects for and new horizons in fibre optic sensors into the future.

As the high rotating speed of air bearing in astronautic gyro, the geometrical parameters (radius, sphericity) of its hemispherical contour must be with ultrahigh accuracy in the order of sub-micrometer. The non-contact pneumatic measurement technique is applied. In this paper, a new type of “air-pin” so-called pneumatic electronic sensor developed by the authors is introduced first. This sensor consists of fine nozzle of less than 0.15 mm in diameter, and its measurement resolution is 0.01 µm, measurement repeatability is within ± 0.05 µm. The spherical pneumatic gauge with multi-nozzles and sensors is used in a computer-based testing system to measure radius and sphericity of hemispherical surface. The measurement uncertainty of this system is less than ± 0.5 µm. It has been used in a project of measuring hemispherical surface of an air bearing of astronautic gyro. It can also be used to measure different three dimension contour in precision engineering

The subject of the paper is focused on novel utilization of super-efficient light-emitting diodes (LEDs) as measuring sources of optical radiation when the determined current pulses are used to drive them. The relationships between input electrical pulse parameters, such as the amplitude and duty factor, and output optical power are studied. Results of LEDs dynamics analysis and experiments made on representative elements are reported. An especially designed generator was used to obtain standard rectangular current pulses needed to evaluate LEDs optical responses.