An extremely small optical displacement sensor using a laser diode integrated with a microlens and based on the composite cavity principle was constructed. The microlaser displacementmeter has been developed using this optical sensor. The measuring resolution of the displacement is less than 0.01 µm and it can detect very low velocities of less than 5 µm/s. The optical sensor is very small, 800 µm × 900 µm. The microlaser displacementmeter shows good linearity between relative displacement and output signal.

This paper proposes a contactless displacement measurement system based on a temperature compensated light-to-frequency (L/F) converter. The optical displacement sensor is represented by the L/F converter excited by a LASER beam. To compensate the temperature drift error of the displacement sensor, an additional temperature measurement system based on a temperature transducer is required. The processing of the data delivered by the sensors is on-line performed using a neural algorithm implemented on a Digital Signal Processor. The Artificial Neural Network architecture used in the present application is Multiple Inputs – Single Output (MISO) type, and the output of the network represents the displacement value after an on-line temperature correction. In the calibration phase of the displacement measurement system a closed-loop motorised linear actuator controlled by a plug-in-PC motion board is added to the system.

The wide scale inspection of extended technical components with respect to the recognition of typical surface features (shape, texture, roughness) needs the combined application of different measurement techniques together with new tools for the consistent analysis and description of the measuring results. The new concept of scalable topometry meets the demands of wide scale surface topometry. Controlled by the evaluation of scale-independent surface features based on fractal geometry, different measurement techniques with subsequent lateral and depth resolution are applied to the surface. As result a complete description of the surface is delivered taking into account special regions of interest. The choice and orientation of the special measurement technique is supported by a new feature extraction method called the fractal pyramid. The advantages of the new concept are demonstrated on example of a ceramic plate with surface faults.

Reflection ellipsometry is a proven optical measurement method often used to measure film thicknesses. Classical ellipsometers use an unfocused measurement beam, which causes a low lateral resolution in the order of 1 mm. To determine microstructures ellipsometrically (e.g. in the semiconductor industry), an improved lateral resolution in the order of micrometers is essential. We discuss the problems of focusing ellipsometry, occurring when a reflection ellipsometer is used to measure surface characteristics (topography, material). Different measurement setups are analyzed and compared. Simulating calculations show that particularly the measured values of the phase difference Δ are influenced by beam focusing. This leads to errors particularly in the attenuation index k of the surface material.

Spectroscopic methods have been for years widely used in analytical laboratories. However, their application in industrial and environmental practice has been up to now relatively limited because of the high costs of spectrometric instrumentation. This is only recently that the advances of micro- and optoelectronics have made feasible integrated implementation of some spectrometric techniques and the design of low-cost spectrometers for industrial applications. The integration implies a significant reduction of instruments precision – mainly due to miniaturisation. This loss, however, may be partially compensated for by digital signal processing of raw spectrometric data. An algorithmic basis for a low-cost computer-assisted spectrometric system – that can be effectively used for qualitative and quantitative analyses of multicomponent chemical substances – is proposed in this paper.