title: Space-domain lock-in amplifier based on a liquid-crystal spatial light modulator.
abstract: We present a two-dimensional (2D) spatial lock-in amplifier that provides a contrast ratio of more than 10,000:1 for transmitted and blocked intensity patterns using a conventional liquid-crystal spatial light modulator. The device is based on spatial-domain modulation-demodulation of intensity patterns under coherent imaging conditions. The operation of the 2D lock-in amplifier is illustrated by implementing Young's double-slit arrangement for measurements of the mutual coherence between individual emitters of a 2D phase-coupled array of vertical cavity surface emitting lasers.
authors.affiliation: Ecole Polytechnique Fédérale de Lausanne, Laboratory of Physics of Nanostructures, CH-1015 Lausanne, Switzerland.
authors.forename: Gregory P
authors.initials: GP
authors.lastname: Lousberg
authors.forename: Lars D A
authors.initials: LD
authors.lastname: Lundeberg
authors.forename: Dmitri L
authors.initials: DL
authors.lastname: Boiko
authors.forename: Eli
authors.initials: E
authors.lastname: Kapon