29116
To extend light transmission beyond lambda = 3 . 7 mu m , a spectral region where a typical silicon dioxide under - clad is absorbing , we fabricate a unique air - clad silicon pedestal waveguide .
 Chemical: silicon dioxide; Chemical: silicon
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: silicon dioxide, silicon 
Answer:
 Chemical: silicon dioxide; Chemical: silicon