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From the mere pushing to sorting of microparticles and assembly of microrobots by light
Zemánek, Pavel ; Arzola, Alejandro V. ; Brzobohatý, Oto ; Chvátal, Lukáš ; Jákl, Petr ; Kaňka, Jan ; Karásek, Vítězslav ; Šerý, Mojmír ; Šiler, Martin
We demonstrate the recent progress in the field of optical micromanipulation. We start with the classical applications of solar sail propelled by the radiation pressure and approach the recent ones dealing with optical tractor beams, optical binding and sorting of microobjects. The pioneering attempts to assemble a microrobot by light is presented.
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Raman tweezers in microfluidic systems for automatic analysis and sorting of living cells
Pilát, Zdeněk
We have devised an automatic analytical and sorting system combining optical trapping with Raman spectroscopy in microfluidic environment, together with computerized real time image analysis, spectra processing and micromanipulation. This device serves to identify and sort biological objects, such as living cells of various prokaryotic and eukaryotic organisms based on their Raman spectral properties. This approach allowed us to collect information about the chemical composition of the objects, such as the presence and composition of lipids, proteins, or nucleic acids without using artificial chemical probes such as fluorescent markers. The non-destructive and non-contact nature of this optical analysis and manipulation allowed us to separate individual living cells of our interest in a sterile environment and provided the possibility to cultivate the selected cells for further experiments. The special microfluidic chip uses gravity to move the cells across the sorting area. Our system uses dedicated software to achieve fully automated spectral analysis and sorting. The devised system is a robust and universal platform for non-contact sorting of microobjects based on their chemical properties. It could find its use in many medical, biotechnological, and biological applications.
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Interferometric measurement system for cost effective e-beam writer
Řeřucha, Šimon ; Šarbort, Martin ; Lazar, Josef ; Číp, Ondřej
The reliability of nanometer track writing in the large scale chip manufacturing process depends mainly on a precise positioning of the e-beam writer moving stage. The laser interferometers are usually employed to control this positioning, but their complicated optical scheme leads to an expensive instrument which increases the e-beam writer’s manufacturing costs. We present a new design of an interferometric system useful in a currently developed cost effective e-beam writers. Our approach simplifies the optical scheme of known industrial interferometers and shifts the interference phase detection complexity from optical domain to the digital signal processing part. Besides the effective cost, the low number of optical components minimizes the total uncertainty of this measuring instrument. The scheme consists of a single wavelength DFB laser working at 1550 nm, one beam splitter, measuring and reference reflectors and one photo-detector at the interferometer output. The DFB laser is frequency modulated by slight changes of injection current while the interference intensity signal is processed synchronously. Our algorithm quantifies the phase as two sinusoidal waveforms with a phase offset equal to the quarter of the DFB laser wavelength. Besides the computation of these quadrature signals, the scale linearization techniques are used for an additional suppression of optical setup imperfections, noise and the residual amplitude modulation caused by the laser modulation. The stage position is calculated on basis of the DFB laser wavelength and the processed interference phase. To validate the precision and accuracy we have carried out a pilot experimental comparison with a reference interferometer over the 100 mm measurement range. The first tests promise only 2 nm deviation between simplified and the reference interferometer.
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Station for LIDT tests of optical components under cryogenic conditions
Oulehla, Jindřich
In this contribution we present a technology for deposition and testing of interference coatings for optical components designed to operate as in power pulsed lasers. We designed and are building a testing apparatus which will serve as an addition to our existing optical coating production facility. This allows us to prepare a coating which is then tested and the results might be used to optimize it. The test samples are placed in a vacuum chamber, cooled down to approximately 120K and Illuminated by a pulsed laser to determine laser damage threshold of the coatings under conditions similar to real life operation. Optical microscopy and spectrophotometer measurements are used for coating investigation after the conducted experiments.
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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.
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The 50th Anniversary of the HeNe Lasers in Czechoslovakia
Kršek, Jiří
The first seminar in Czechoslovakia to New Sources of Light ( Quantum Generators of Light ) took place at Liblice Castle, Central Bohemia, in March of 1963 and on October 16th the same year of 1963 the HeNe laser was placed into operation at the Institute of Scientific Instruments of the ASCR ( ISI ASCR ) in Brno, Czech Republic. The article presented the achievements of HeNe lasers at ISI ASCR in Brno, accompanied by historic photos, their specified applications and routes to production through the manufacturingprocess at the national companies of Meopta located in Prerov and Metra in Blansko.
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