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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The optical lever is a centuries old and widely-used detection techniqueemployed in applications ranging from consumer products, industrial sensors toprecision force microscopes used in scientific research. However, despite thelong history, its quantum limits have yet to be explored. In general, anyprecision optical measurement is accompanied by optical force induceddisturbance to the measured object (termed as back action) leading to astandard quantum limit(SQL). Here we give a simple ray optics description ofhow such back action can be evaded in optical lever detection to beat SQL. Weperform a proof-of-principle experiment demonstrating the mechanism of backaction evasion in the classical regime, by developing a lens system thatcancels extra tilting of the reflected light off a silicon nitride membranemechanical resonator caused by laser-pointing-noise-induced optical torques. Weachieve a readout noise floor two orders of magnitude lower than the SQL,corresponding to an effective optomechanical cooperativity of 100 without theneed for an optical cavity. As the state-of-the-art ultra low dissipationoptomechanical systems relevant for quantum sensing are rapidly approaching thelevel where quantum noise dominates, simple and widely applicable back actionevading protocols will be crucial for pushing beyond quantum limits.

Back action evasion in optical lever detection