7158
When the wave front of the emitted beam has perturbations , only the transverse coherence length ( where the wave front perturbation is less than 1 / 4 of the wavelength ) should be considered as a Gaussian beam diameter when determining the divergence of the laser beam .
 person: Gaussian
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 person: Gaussian