Optical transmission loss in liquid-core hollow fibers

Multimode optical fibers consisting of glass cladding and liquid core have been constructed. For a cladding index of refraction of 1.52 and a core of bromobenzene, index of 1.560, a loss of 0.140 dB/m has been measured over lengths of about 50 m. The loss measured with incoherent light is higher due to the presence of higher order modes. Strong absorption in the near infrared occurs in narrow wavebands associated with overtones of the C-H fundamental vibration frequency.