title: Efficiency pedestal in quasi-phase-matching devices with random duty-cycle errors.
abstract: It is shown that random duty-cycle errors in quasi-phase-matching (QPM) nonlinear optical devices enhance the efficiency of processes far from the QPM peak. An analytical theory is shown to agree well with numerical solutions of second-harmonic generation (SHG) in disordered QPM gratings. The measured efficiency of 1550 nm band SHG in a periodically poled lithium niobate (PPLN) waveguide away from the QPM peak agrees with observations of domain disorder in a PPLN wafer by Zygo interferometry. If suppression of parasitic nonlinear interactions is important in a specific application of QPM devices, control of random duty-cycle errors is critical.
authors.affiliation: E L Ginzton Laboratory, Stanford University, Stanford, California 94305, USA. jpelc@stanford.edu
authors.forename: J S
authors.initials: JS
authors.lastname: Pelc
authors.forename: C R
authors.initials: CR
authors.lastname: Phillips
authors.forename: D
authors.initials: D
authors.lastname: Chang
authors.forename: C
authors.initials: C
authors.lastname: Langrock
authors.forename: M M
authors.initials: MM
authors.lastname: Fejer