Squeezed vacuum states from a whispering gallery mode resonator

Alexander Otterpohl*, Florian Sedlmeir, Ulrich Vogl, Thomas Dirmeier, Golnoush Shafiee, Gerhard Schunk, Dmitry V. Strekalov, Harald G. L. Schwefel, Tobias Gehring, Ulrik Lund Andersen, Gerd Leuchs, Christoph Marquardt

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

182 Downloads (Pure)


Squeezed vacuum states enable optical measurements below the quantum limitand hence are a valuable resource for applications in quantum metrology andalso quantum communication. However, most available sources require high pumppowers in the milliwatt range and large setups, which hinders real world applications. Furthermore, degenerate operation of such systems presents achallenge. Here, we use a compact crystalline whispering gallery mode resonator made of lithium niobate as a degenerate parametric oscillator. We demonstrate about 1.4 dB noise reduction below the shot noise level for only 300 μW of pump power in degenerate single mode operation. Furthermore, we report a record pump threshold as low as 1.35 μW. Our results show that the whispering gallery based approach presents a promising platformfor a compact and efficient source for nonclassical light.
Original languageEnglish
Issue number11
Pages (from-to)1375-1380
Number of pages6
Publication statusPublished - 2019


Dive into the research topics of 'Squeezed vacuum states from a whispering gallery mode resonator'. Together they form a unique fingerprint.

Cite this