Purified quartz powder modified for cladding optic fiber cable

[0026]The blended mass of powder had 1 ppm lithium and was gassed by AHCI at 1250° C. to give a solid solution lithium level in the final product of 0.823 ppm. The attenuation was reduced to a level below 0.187 dB / km.

[0027]The blended mass of powder had 0.83 ppm lithium and was gassed by AHCI at 1250° C. to give a solid solution lithium level in the final product of 0.665, which conforms to the desired targeted level. Example 2 was tested and found the attenuation was 0.183 dB / km. This constitutes the primary object of the invention to decrease the attenuation by using high lithium and preferably an attenuation level less than 0.184 dB / km.

[0028]Broadly the added lithium of the invention is an improvement because it reduces the attenuation obtained when purified quartz is used as cladding of optic fiber cable over prior art purified quartz powder. Example 1 was acceptable for improving commercial purified quartz powder for cladding. However, Example 1 was determined to be near the upper limit of the solid solution level to accomplish the inventive improvement of purified quartz powder for the fiber optic industry. Example 2 was preferred because it reduced the lower attenuation of the invention t...

[0030]This example was formulated by suing Li2CO3 from supply 46. It was determined that if the preferred maximum amount of total lithium in the blended mass of powder from station 14, i.e. 1.0 ppm, doping by gassing 70 of method 10 resulted in the final solid solution of lithium to about 0.4 ppm which, is less than the lithium level of the present invention. Consequently, more lithium carbonate doping agent is needed to practice the invention. It is less efficient in its doping action. It was found that LiCl from supply 42 performed as Example 3. Consequently, testing to obtain the lithium level of the invention established that lithium nitrate from supply 44 is preferred, the other similar doping agents from supplies 42 and 46 required higher levels of lithium at station 14.