26406
We report the observation of simultaneous two and three photon resonances , enhancing the third - order NLO susceptibility in a thin film of an azo - dye polymer .
 Chemical: azo
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: azo