title: Conical harmonic generation in isotropic materials.
abstract: A novel class of nonlinear optical processes is described in which radiation at the nth harmonic is generated through the use of a (2n+1)-order nonlinearity. Utilizing an odd-order nonlinearity, this process allows for the generation and amplification of both odd- and even-order harmonics in isotropic materials. Additionally, this process can always be phase matched in normal-dispersion materials without the use of birefringence. Experimental results are presented in which conical third-harmonic emission is generated from a sapphire sample.
authors.affiliation: School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA.
authors.forename: K D
authors.initials: KD
authors.lastname: Moll
authors.forename: D
authors.initials: D
authors.lastname: Homoelle
authors.forename: Alexander L
authors.initials: AL
authors.lastname: Gaeta
authors.forename: Robert W
authors.initials: RW
authors.lastname: Boyd