Raman measurements of optical absorption and heat transfer coefficients of a single carbon fiber in atmosphere environment

In this paper, the optical absorption and heat transfer coefficients of a single suspended 4.3 μm diameter carbon fiber have been measured in the experiment. The test fiber was first heated locally by a laser beam and the temperature rise was measured from the shifts in the Raman G-band frequency, and then the laser heating was replaced by an electrical current heating, the electrical power was adjusted to have the same temperature rise. Since the electrical power can be measured accurately, the absorbed laser power can be extracted from one-dimensional heat conduction analysis and the heat transfer coefficient can be obtained as well. The present experimental results show that the optical absorption of 4.3 μm diameter carbon fiber is 39.62% and the heat transfer coefficient is 4150 Wm^-2 K^-1, which agrees well with the prediction of published experimental empirical formula.