The doctoral dissertations of the former Helsinki University of Technology (TKK) and Aalto University Schools of Technology (CHEM, ELEC, ENG, SCI) published in electronic format are available in the electronic publications archive of Aalto University - Aaltodoc.
Aalto

Development of Detectors and Calibration Methods for Spectral Irradiance and Radiometric Temperature Measurements

Mart Noorma

Dissertation for the degree of Doctor of Science in Technology to be presented with due permission of the Department of Electrical and Communications Engineering for public examination and debate in Auditorium S4 at Helsinki University of Technology (Espoo, Finland) on the 6th of July, 2005, at 12 o'clock noon.

Overview in PDF format (ISBN 951-22-7748-4)   [457 KB]
Dissertation is also available in print (ISBN 951-22-7747-6)

Abstract

The research work, described in this thesis, has been carried out at the Metrology Research Institute of Helsinki University of Technology between 2000 and 2005. The research focused on the development of new detectors, calibration methods and their applications in optical radiometry.

A new photodetector, which is based on three GaAsP Schottky-barrier photodiodes, has been introduced. The spectral properties of the GaAsP trap detector have been studied in the wavelength range between 200 nm and 600 nm. Spectral reflectance of a single windowless GaAsP photodiode, measured with high-accuracy gonioreflectometer, has been presented. Based on these measurements, the internal quantum efficiencies for both the single photodiode and the trap detector have been calculated.

A novel scanning method for characterization of filter radiometers, which uses a wavelength tuneable Ti:Sapphire laser source, has been described. High accuracy calibration of filter radiometers at 900 nm has been conducted. The results have been compared to the spectral irradiance responsivities measured with the more conventional monochromator-based method.

Both the laser-based method and the monochromator-based method have been used for characterization of the detectors for radiometric measurements of the thermodynamic temperatures of several blackbodies in irradiance mode. Four filter radiometers with central wavelengths between 600 nm and 900 nm have been used. The measured temperatures include the freezing temperature of silver and copper, which are defined by the International Temperature Scale of 1990.

This thesis consists of an overview and of the following 4 publications:

  1. M. Noorma, P. Kärhä, A. Lamminpää, S. Nevas, and E. Ikonen. 2005. Characterization of GaAsP trap detector for radiometric measurements in ultraviolet wavelength region. Review of Scientific Instruments 76, 033110, 5 pages.
  2. M. Noorma, P. Toivanen, F. Manoocheri, and E. Ikonen. 2003. Characterization of filter radiometers with a wavelength-tunable laser source. Metrologia 40, S220-S223.
  3. M. Noorma, P. Kärhä, T. Jankowski, F. Manoocheri, T. Weckström, L. Uusipaikka, and E. Ikonen. 2004. Absolute detector-based radiometric temperature scale. Proceedings of the 9th International Symposium on Temperature and Thermal Measurements in Industry and Science (TEMPMEKO 2004), accepted for publication.
  4. M. Noorma, V. Ahtee, A. Lamminpää, P. Kärhä, F. Manoocheri, T. Weckström, and E. Ikonen. 2005. Radiometric temperature measurements with absolutely characterized filter radiometers in irradiance mode. Helsinki University of Technology, Metrology Research Institute Report 24/2005.

Keywords: optics, metrology, radiometry, thermometry, optical detectors

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© 2005 Helsinki University of Technology

Last update 2011-05-26