7514
It also points to the importance of a localized emitter for radiating Raman photons to the far - field which , in nonsymmetric systems , allows for the excitation of radiative plasmon modes that are difficult to excite with plane waves .
 None
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:  
Answer:
 None