已经制出了采用溴化铊和碘溴化铊的新型纤维光波导;它的红外领域的透光性扩展到超过已知玻璃材料传光的波长。用挤出工艺已经制造出了用多晶溴化铊和碘溴化铊芯线的新的纤维光波导。为完成这个波导,把多晶芯线插在松紧适当的聚合物包层中(图1),包层既作为导模的光限制,又作为晶状芯线的机械保护. New fiber optic waveguides using thallium bromide and thallium iodide bromide have been made; their light transmission in the infrared range has been extended beyond the wavelength of light transmission of known glass materials. New fiber optic waveguides using polycrystalline thallium bromide and a thallium iodobromide core have been made by extrusion processes. In order to complete this waveguide, the polycrystalline core is inserted in a suitably elastic polymer cladding (Figure 1). The cladding acts both as a light guide for the guided mode and as a mechanical protection for the crystalline core.