title: Orthogonal spectral coding of entangled photons.
abstract: We extend orthogonal optical coding, previously applied to multiuser classical communication networks, to entangled photons. Using a pulse shaper and sum-frequency generation for ultrafast coincidence detection, we demonstrate encoding and decoding of biphoton wave packets. Applying one code to the signal photon spreads the wave packet in time and creates a null at zero delay; filtering the idler with the matched code recovers a narrow correlation peak, whereas applying any other code leaves the wave packet spread. Our results could prove useful in the development of code-based quantum communication networks.
authors.affiliation: School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, USA.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Lukens
authors.affiliation: School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, USA.
authors.forename: Amir
authors.initials: A
authors.lastname: Dezfooliyan
authors.affiliation: E. L. Ginzton Laboratory, Stanford University, Stanford, California 94305, USA.
authors.forename: Carsten
authors.initials: C
authors.lastname: Langrock
authors.affiliation: E. L. Ginzton Laboratory, Stanford University, Stanford, California 94305, USA.
authors.forename: Martin M
authors.initials: MM
authors.lastname: Fejer
authors.affiliation: School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, USA.
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Leaird
authors.affiliation: School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, USA.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Weiner