Using a complex optical orbital-angular-momentum spectrum to measure object parameters

Guodong Xie*, Haoqian Song, Zhe Zhao, Giovanni Milione, Yongxiong Ren, Cong Liu, Runzhou Zhang, Changjing Bao, Long Li, Zhe Wang, Kai Pang, Dmitry Starodubov, Brittany Lynn, Moshe Tur, Alan E. Willner

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Light beams can be characterized by their complex spatial profiles in both intensity and phase. Analogous to time signals, which can be decomposed into multiple orthogonal frequency functions, a light beam can also be decomposed into a set of spatial modes that are taken from an orthogonal basis. Such decomposition can potentially provide a tool for spatial spectrum analysis, which may enable stable, accurate, and robust extraction of physical object information that may not be readily achievable using traditional approaches. As a proof-of-concept example, we measure an object’s opening angle using orbital-angular-momentum (OAM) -based complex spectrum, achieving a >15 dB signal-to-noise ratio. Moreover, the dip (i.e., notch) positions of the OAM intensity spectrum are dependent on an object’s opening angle but independent of the opening’s angular orientation, whereas the slope of the OAM phase spectrum is dependent on the opening’s orientation but independent of the opening angle.

Original languageEnglish
Pages (from-to)4482-4485
Number of pages4
JournalOptics Letters
Issue number21
StatePublished - 1 Nov 2017


FundersFunder number
National Science FoundationECCS-1509965
Office of Naval ResearchN00014-16-1-2813
Office of the Assistant Secretary for Research and Technology


    Dive into the research topics of 'Using a complex optical orbital-angular-momentum spectrum to measure object parameters'. Together they form a unique fingerprint.

    Cite this