Quantum enhanced LIDAR resolution with multi-spatial-mode phase sensitive amplification

Cesar A. Santivanez, Saikat Guha, Zachary Dutton, Muthiah Annamalai, Michael Vasilyev, Brent J. Yen, Ranjith Nair, Jeffrey H. Shapiro

Research output: Chapter in Book/Report/Conference proceedingConference contribution

11 Scopus citations


Phase-sensitive amplification (PSA) can enhance the signal-to-noise ratio (SNR) of an optical measurement suffering from detection inefficiency. Previously, we showed that this increased SNR improves LADAR-imaging spatial resolution when infinite spatial-bandwidth PSA is employed. Here, we evaluate the resolution enhancement for realistic, finite spatial-bandwidth amplification. PSA spatial bandwidth is characterized by numerically calculating the input and output spatial modes and their associated phase-sensitive gains under focused-beam pumping. We then compare the spatial resolution of a baseline homodyne-detection LADAR system with homodyne LADAR systems that have been augmented by pre-detection PSA with infinite or finite spatial bandwidth. The spatial resolution of each system is quantified by its ability to distinguish between the presence of 1 point target versus 2 closely-spaced point targets when minimum error-probability decisions are made from quantum limited measurements. At low (5-10 dB) SNR, we find that a PSA system with a 2.5kWatts pump focused to 25μm × 400μm achieves the same spatial resolution as a baseline system having 5.5 dB higher SNR. This SNR gain is very close to the 6 dB SNR improvement possible with ideal (infinite bandwidth, infinite gain) PSA at our simulated system detection efficiency (0.25). At higher SNRs, we have identified a novel regime in which finite spatial-bandwidth PSA outperforms its infinite spatial-bandwidth counterpart. We show that this performance crossover is due to the focused pump system's input-to-output spatial-mode transformation converting the LADAR measurement statistics from homodyne to heterodyne performance.

Original languageEnglish (US)
Title of host publicationQuantum Communications and Quantum Imaging IX
StatePublished - 2011
EventQuantum Communications and Quantum Imaging IX - San Diego, CA, United States
Duration: Aug 24 2011Aug 25 2011

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X


ConferenceQuantum Communications and Quantum Imaging IX
Country/TerritoryUnited States
CitySan Diego, CA


  • Phase-Sensitive Amplification (PSA)
  • homodyne detection
  • multi-mode PSA

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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