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Title: Quantum-limited optical lever measurement of a torsion oscillator
The optical lever is a precision displacement sensor with broad applications. In principle, it can track the motion of a mechanical oscillator with added noise at the standard quantum limit (SQL); however, demonstrating this performance requires an oscillator with exceptionally high torque sensitivity or, equivalently, zero-point angular displacement spectral density. Here, we describe optical lever measurements on nanoribbons possessing torsion modes with torque sensitivities of and zero-point displacement spectral densities of . By compensating for aberrations and leveraging immunity to classical intensity noise, we realize angular displacement measurements with imprecisions 20 dB below the SQL and demonstrate feedback cooling, using a position-modulated laser beam as a torque actuator, from room temperature to Si3N4phonons. Our study signals the potential for a new class of torsional quantum optomechanics.  more » « less
Award ID(s):
2239735
PAR ID:
10577483
Author(s) / Creator(s):
; ;
Publisher / Repository:
Optical Society of America
Date Published:
Journal Name:
Optica
Volume:
12
Issue:
3
ISSN:
2334-2536
Format(s):
Medium: X Size: Article No. 418
Size(s):
Article No. 418
Sponsoring Org:
National Science Foundation
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