Calculating of Absorption Loss Due to High Harmonics of C-H Vibrations in PMMA POF

Absorption loss due to high harmonics of C-H vibrations, the primary loss factor in PMMA POF, was analyzed and calculated. And the results were consistent with measured datas. The mechanism that deuterating and fluorinating could decrease loss of POF was theoretically approved. Absorption wavenumber and loss of streching vibration and bending vibration of different quantum number were obtained. With increasing of wavelength, absorption loss due to high harmonics of C-H vibrations increased and absorption loss of stretching vibration was higher one order of magnitude than that of bending vibration, and both was in proportion to quantum number respectively.