A Calorimetric Technique for the Measurement of Low Optical Absorption Losses in Bulk Glass and Optical Communication Fibres

  • K I White
  • J E Midwinter
Part of the Optical Physics and Engineering book series (OPEG)


In the bulk glass measurement, a pair of thin rod samples are rigidly mounted in a massive brass enclosure. As the rod ends are immersed in index matching liquid, no optical polishing is necessary. One sample is illuminated by a laser beam and the temperature rise due to the absorbed energy is measured by a thermocouple. For the fibre measurement, the solid rod is replaced by a fibre led through a silica tube filled with a low index liquid. A laser power of 100mW gives a sensitivity of 1dB/Km limited by thermocouple Johnson noise. Replacing the fibre by a fine resistance wire conducting a known current provides a calibration of the apparatus.


Silica Tube Bulk Glass Fibre Absorption Direct Illumination Thermocouple Wire 


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  1. [1]
    K G Kao and T W Davies, J. Sci. Instr 1 (1968) 1063–1068ADSCrossRefGoogle Scholar
  2. C R Wright and K C Kao, J. Sci. Instr 2 (1969) 331–335CrossRefGoogle Scholar
  3. [2]
    D A Pinnow, T C Rich, F W Ostermeyer, Jr., and M Di Domenico, Jr., Appl. Phys. Lett. 22(1973) 527–529ADSCrossRefGoogle Scholar
  4. [3]
    F W Ostermeyer Jr., and W W Benson, Appl. Opt. 13 (1974) 1900–1902ADSCrossRefGoogle Scholar
  5. [4]
    K I White and J E Midwinter, Opto-electronics 5 (1973) 323–334CrossRefGoogle Scholar
  6. [5]
    H S Carslaw and J C Jaeger, Conduction of Heat in Solids, p 493 Clarendon Press, Oxford (1959)Google Scholar
  7. [6]
    D E Sharp and L B Gînther, J. Am. Ceram. Soc. 34 (1951) 260–271CrossRefGoogle Scholar
  8. [7]
    Johnson Matthey Metals Ltd, London UKGoogle Scholar
  9. [8]
    Keithley Instruments, Ohio, USAGoogle Scholar

Copyright information

© Plenum Press, New York 1975

Authors and Affiliations

  • K I White
    • 1
  • J E Midwinter
    • 1
  1. 1.Post Office Research CentreMartlesham HeathIpswich, SuffolkUK

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