English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The ability to measure nanoradian polarization rotations, $\theta_F$, in thephoton shot noise limit is investigated for partially crossed polarizers (PCP),a static Sagnac interferometer and an optical bridge, each of which can inprincipal be used in this limit with near equivalent figures-of-merit (FOM). Inpractice a bridge to PCP/Sagnac source noise rejection ratio of $1/4\theta_F^2$enables the bridge to operate in the photon shot noise limit even at high lightintensities. The superior performance of the bridge is illustrated via themeasurement of a 3 nrad rotation arising from an axial magnetic field of 0.9 nTapplied to a terbium gallium garnet. While the Sagnac is functionallyequivalent to the PCP in terms of the FOM, unlike the PCP it is able todiscriminate between rotations with different time ($T$) and parity ($P$)symmetries. The Sagnac geometry implemented here is similar to that usedelsewhere to detect non-reciprocal ($\overline{T}P$) rotations like those dueto the Faraday effect. Using a Jones matrix approach, novel Sagnac geometriesuniquely sensitive to non-reciprocal $\overline{TP}$ (e.g. magneto-electric ormagneto-chiral) rotations, as well as to reciprocal rotations (e.g. due tolinear birefringence, $TP$, or to chirality, $T\overline{P}$) are proposed.

Polarizers, optical bridges and Sagnac interferometers for nanoradian polarization rotation measurements