Razvoj sustava za interferencijsko umjeravanje etalona duljine metodom faznih pomaka

doctoral thesis

• Title (english): Development of interferometric system for calibration of lenght standards using phase shifting method
• Author: Marko Katić
• Mentor: Vedran Mudronja (mentor)
• Committee member: Hrvoje Zorc (predsjednik povjerenstva)
• Committee member: Vedran Mudronja (član povjerenstva)
• Committee member: Biserka Runje (član povjerenstva)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2013-05-07, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; Production Mechanical Engineering
• Universal decimal classification (UDC): 67/68 - Various industries, trades and crafts

Abstract

Prijenos valne duljine primarnog etalona na fizičke etalone predstavlja najvišu razinu u osiguravanju sljedivosti mjerenja duljine; osnovni je cilj ovog rada tu najvišu razinu u osiguravanju sljedivosti ostvariti u \Nacionalnom laboratoriju za duljinu. U radu su predstavljene modifikacije postojećeg interferometra kojima je omogućeno korištenje laserskih izvora svjetla, te dodatne modifikacije kojima su poboljšane mjeriteljske karakteristike i smanjena nesigurnost interferencijskog umjeravanja etalona duljine primjenom postojećeg interferometra. Pri tome je implementirana i metoda faznih pomaka čime je ostvarena rezolucija mjernog sustava ispod jednog nanometra, a mogućnosti unaprijeđenog interferometra potvrđene su međunarodnom usporedbom. Po završetku ove faze istraživanja pokrenut je projekt izrade novog interferometra, kojim se željelo omogućiti dodatna istraživanja. Izrađen je Twyman-Green interferometar koji omogućuje kvalitetniju implementaciju metode faznih pomaka, kao i simultanu primjenu više valnih duljina, čime su izbjegnuti najizraženiji nedostaci do sada korištenog interferometra. Konačno, osmišljena je metoda za direktno mjerenje kontaktnog sloja, što do sada nije bilo moguće, te nova metoda za utvrđivanje fazne korekcije; obje su metode koncipirane tako da budu univerzalno primjenjive, bez obzira na specifičnu vrstu interferometra u kojem se koriste. U radu su prikazani izvodi i rezultati tih metoda, koji potvrđuju njihov doprinos u smanjenju mjerne nesigurnosti.

Abstract (english)

Describing the length of physical standards in terms of wavelength of a primary length standard represents the highest level of traceability for length; the basic goal of this research is to provide this level of traceability in Croatian National laboratory for length. Extensive modifications were made on a Zeiss gauge block interferometer to achieve this goal; a new optical system was made to allow use of laser light sources and establish traceability, and numerous additional modifications were made to upgrade measurement possibilities and to reduce overall uncertainty for gauge block calibration. These modifications span through the entire measurement system, from improved environmental conditions and digital sensors for their measurement, to improved digital acquisition and analysis of interferograms. Phase shifting interferometry was also implemented in Zeiss interferometer, increasing its resolution below nanometre level. Performance of these modifications was verified through EURAMET Key Comparison with several European institutes. After this phase of research was complete, development of a new gauge block interferometer was started. As a result, a Twyman-Green interferometer was built, enabling implementation of Synthetic Wavelength Phase Shifting Interferometry. This interferometer was thoroughly tested, and results indicate that it can match the performance of commercial gauge block interferometers. Finally, as direct result of research described above, two new measurement methods have been proposed. A novel method for direct measurement of wringing layer was tested, with very good results. This method eliminates the variability of wringing layer thickness, without the need for additional measurement equipment, and therefore provides a universal tool for reduction of measurement uncertainty for absolute gauge block calibration. Combination of this method with a modified stack method resulted in a new method for determination of phase correction, which greatly reduces the uncertainty of phase correction and enables its determination with just a fraction of previously required measurements.

• Keywords: sljedivost; umjeravanje etalona duljine; interferometar za granične mjerke; metoda faznih pomaka
• Keywords (english): traceability; gauge block calibration; gauge block interferometry; phase shifting interferometry
• Language: croatian
• URN:NBN: urn:nbn:hr:235:199815
• Study programme: Title: Mechanical Engineering and Naval Architecture; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, područje tehničkih znanosti (doktor/doktorica znanosti, područje tehničkih znanosti)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2020-04-30 08:17:28