Optical fibre-coupled cryogenic radiometer with carbon nanotube absorber

Published

March 2, 2012

Author(s)

David J. Livigni, Nathan A. Tomlin, Christopher L. Cromer, John H. Lehman

Abstract

A cryogenic radiometer was constructed for direct-substitution optical-fibre power measurements. The cavity is intended to operate at the 3 K temperature stage of a dilution refrigerator or 4.2 K stage of a liquid cryostat. The optical fibre is removable for characterization. The cavity features micromachined silicon centring rings to thermally isolate the optical fibre as well as an absorber made from micromachined silicon on which vertically aligned carbon nanotubes were grown. Measurements of electrical substitution, optical absorption and temperature change indicate that the radiometer is capable of measuring a power level of 10 nW with approximate responsivity of 155 nW K^-1 and 1/e time constant of 13 min. An inequivalence between optical and electrical power of approximately 10% was found, but the difference was largely attributable to unaccounted losses in the optical fibre.

Proceedings Title

11th International Conference on New Developments and Applications in Optical Radiometry

Volume

49

Issue

2

Conference Dates

September 18-23, 2011

Conference Location

Maui, HI

Pub Type

Conferences

Keywords

carbon nanotube, micromachining, optical fiber, radiometry

Citation

Livigni, D. , Tomlin, N. , Cromer, C. and Lehman, J. (2012), Optical fibre-coupled cryogenic radiometer with carbon nanotube absorber, 11th International Conference on New Developments and Applications in Optical Radiometry, Maui, HI (Accessed October 15, 2025)