title: Ultrasensitive second-harmonic generation frequency-resolved optical gating by aperiodically poled LiNbO3 waveguides at 1.5 microm.
abstract: We retrieve intensity and phase profiles of 280 fs, 50 MHz optical pulses with 124 aJ coupled pulse energy (960 photons) by second-harmonic generation (SHG) frequency-resolved optical gating, using aperiodically poled LiNbO3 waveguides. The strong nonlinear interaction that is due to confinement within the micrometer-sized waveguide structure and the linearly chirped poling period contribute, respectively, to high SHG efficiency and broad phase-matching bandwidth. The achieved sensitivity is 2.7 x 10(-6) mW2, improving on the previous record for self-referenced complete pulse characterization by 5 orders of magnitude.
authors.affiliation: Purdue University, West Lafayette, Indiana 47907, USA. shangda@purdue.edu
authors.forename: Shang-Da
authors.initials: SD
authors.lastname: Yang
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Weiner
authors.forename: Krishnan R
authors.initials: KR
authors.lastname: Parameswaran
authors.forename: Martin M
authors.initials: MM
authors.lastname: Fejer