Measurements of molecular hyperpolarizabilities for ethylene, butadiene, hexatriene, and benzene

Third‐order polarizabilities are measured in the gas phase using dc electric‐field induced optical second‐ harmonic generation and are found to be positive in each case.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69750/2/JCPSA6-69-12-5438-1.pd