Anomalous amplification of a homodyne signal via almost-balanced weak values

Wei Tao Liu*, Julián Martínez-Rincón, Gerardo I. Viza, John C. Howell

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

22 Scopus citations


We propose precision measurements of ultra-small angular velocities of a mirror within a modified Sagnac interferometer, where the counter-propagating beams are spatially separated, using the recently proposed technique of almost-balanced weak values amplification (ABWV) [Phys. Rev. Lett. 116, 100803 (2016)]. The separation between the two beams provides additional amplification with respect to using collinear beams in a Sagnac interferometer. Within the same setup, the weak-value amplification technique is also performed for comparison. Much higher amplification factors can be obtained using the almost-balanced weak values technique, with the best one achieved in our experiments being as high as 1.2 × 107. In addition, the amplification factor monotonically increases with decreasing of the post-selection phase for the ABWV case in our experiments, which is not the case for weak-value amplification (WVA) at small post-selection phases. Both techniques consist of measuring the angular velocity. The sensitivity of the ABWV technique is ∼38 nrad/s per averaged pulse for a repetition rate of 1 Hz and ∼33 nrad/s per averaged pulse for the WVA technique.

Original languageAmerican English
Pages (from-to)903-906
Number of pages4
JournalOptics Letters
Issue number5
StatePublished - 1 Mar 2017
Externally publishedYes

Bibliographical note

Publisher Copyright:
© 2017 Optical Society of America.


Dive into the research topics of 'Anomalous amplification of a homodyne signal via almost-balanced weak values'. Together they form a unique fingerprint.

Cite this