|
|
Measurement of real-time gigacycle fatigue through real-time interferometry
Lazar, Josef ; Holá, Miroslava ; Hrabina, Jan ; Číp, Ondřej
We present an interferometric method for measurement of strain induced deformation of metal samples in experiments inducing high-cycle fatigue. The motivation is to get real-time information about the deformation of a metal sample under test, its elongation imposed by fast vibrating actuator. Fatigue of materials is a process of degradation of a material due to repeated application of forces which includes nucleation and propagation of cracks and leads to the failure of the component. It may appear in all parts of machines or structures which rotate, vibrate, are repeatedly loaded, are subjected to temperature gradients etc., so statistically, fatigue is implied in about 80% of all industrial failures.
|
|
|
Optical diagnostic methods for energetics
Hrabina, Jan
This work is oriented to non-contacting laser spectroscopy diagnostic methods for monitoring of combustion processes in coal power plant facilities. These methods can be used for optimalization of combustion process in the chamber, which is neccessary step toward reduction of toxic gases releasing in to the atmosphere, increasing of efficiency of the combustion and reduction of overall costs needed for electricity production.
|
|
|
Coordinate interferometric system for measuring the position of a sample of the electron lithograph
Holá, Miroslava ; Lazar, Josef ; Čížek, Martin ; Řeřucha, Šimon ; Číp, Ondřej
This project is called "Platform of advanced microscopic and spectroscopic techniques for nano and microtechnology." The coordinator of this project is the Brno University of Technology / Faculty of Mechanical Engineering and the co-investigators are ON Semiconductor Czech Republic, Ltd., Optaglio Ltd., Tescan Brno, Ltd. And the Institute of Scientific Instruments of the CAS, v. v. i.. In this project we are working on a design of an interferometric measuring system, laser source and detection techniques for a coordinate measuring system of the table of the electron beam lithography.
|
|
|
Optical fiber senzors to measurement length, pressure, tension, temperature and vibration
Mikel, Břetislav
We present new optical fiber sensors based on fiber Bragg gratings to measurement length, pressure, tension, temperature and vibration. We developed systems to monitoring several types of sensors. Measurement of length, tension, pressure and temperature is realized on the same principle of measurement spectral properties of sensors. We used optical filter based system to monitoring optical spectrum reflected from sensors in our system. Sensor with tilted fiber Bragg grating in tapered optical fiber we used to monitoring vibration. This ghost mode reflected from tilted fiber Bragg grating is recoupled into the fiber core in tapered prat of fiber. The measurement system can measure only optical power.
|
|
|
Fiber gratings to nuclear power plant Temelin and theirs calibration by laser interferometer
Mikel, Břetislav
We present application of the optical fiber sensors to measurement the shape deformation of the containment of the nuclear power station Temelin. The presented method can be used to measure any concrete buildings. To prepare optical fiber sensors we developed method of measurement of fiber Bragg gratings (FBG) stretching by laser interferometer. We are oriented to research, development and to methodology of the production and application of FBGs. The elongation of FBGs can calculated from frequency drift of the Bragg resonance wavelength and from the change of the grating period during stretching.
|
|
|
Interferometric coordinates measurement sytem for local probe microscopy nanometrology
Hrabina, Jan ; Lazar, Josef ; Klepetek, P. ; Číp, Ondřej ; Čížek, Martin ; Holá, Miroslava ; Šerý, Mojmír
We present an overview of new approaches to the design of nanometrology measuring system with a focus on methodology of nanometrology interferometric techniques and associated problems. The design and development of a nanopositioning setup with interferometric multiaxis monitoring and control involved for scanning probe microscopy techniques (primarily atomic force microscopy, AFM) for detection of the sample profile is presented. Coordinate position sensing allows upgrading the imaging microscope techniques up to quantified measuring. Especially imaging techniques in the micro- and nanoworld overcoming the barrier of resolution given by the wavelength of visible light are a suitable basis for design of measuring systems with the best resolution possible. The system is being developed in cooperation with the Czech metrology institute and it is intended to operate as a national nanometrology standard combining local probe microscopy techniques and sample position control with traceability to the primary standard of length.
|
|
| |
|
|
The femtosecond optical frequency comb based tool for spectral analysis of molecular absorbtion gases
Lešundák, Adam ; Šmíd, Radek ; Buchta, Zdeněk ; Mikel, Břetislav ; Lazar, Josef ; Randula, A. ; Číp, Ondřej
The spectral analysis of absorption of molecular gases belongs to very powerful methods for detection of concentration of gases in a tested sample. In case of the human breath it consists of hundreds of molecules of gasses and their concentrations are known as biomarkers. An increased concentration of more of them indicates certain diseases or symptoms. The presenting work covers a pilot experiment where femtosecond pulse probe laser and a detection chain based on cross-correlation makes an analysis of the specimen of the absorption gas. In the pilot experimental set-up the detection part utilizes a Michelson interferometer with movable measuring mirror. We developed a novel digital processing method for precise stabilization of the speed of the mirror during measuring process. The caught optical signals are calculated by the fast Fourier transform from the time to wavelength domain. The first caught spectra of the femtosecond beam passing trough the specimens show absorption lines of one isotope of acetylene which was tested as the first sample. The work proofed positive the possibility of using the femtosecond laser for detection of broadband absorption spectra in the infrared region.
|
guest ::
