Quantum Optics Seminar by Jon R. Pratt – Niels Bohr Institute - University of Copenhagen

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Quantum Optics Seminar by Jon R. Pratt

Small Force Metrology at the National Institute of Standards and Technology

Gaithersburg, MD USA, Jon R. Pratt, NIST, Gaithersburg, USA

The atomic force microscope (AFM), optical tweezers, and a variety of other devices have made the measurement of forces below the level of a few micronewtons commonplace, and such measurements are highly valued for testing material and device behavior at the micro and nanoscale.  However, whether the goal is measuring the hardness of semiconductor dielectric layers, or the binding of new drug molecules, the ability to accurately quantify small force measurements in terms of known, verified standards has been lacking. The Small Force Metrology Laboratory (SFML) at NIST was established to address this issue by developing accurate force standards for researchers and manufacturers increasingly reliant on micro and nano-mechanical testing to carry out their product development, fabrication, and quality control.  In this talk, I will examine the evolution of force calibration at NIST, exploring some of the capabilities, techniques, and equipment developed within the SFML for making quantitative small force measurements. I will conclude by discussing a new sensor developed as part of collaboration with the Niels Bohr Institute and the Joint Quantum Institute of the University of Maryland. This force sensor employs an optical cavity integrated with a new type of fused silica mechanical oscillator to yield an accelerometer that can be calibrated using the wavelength of the laser light and the measured frequency of the oscillator. The accelerometer is designed to achieve nano-gn per root hertz (1 gn = 9.81 m/s2) noise amplitude over a bandwidth of several kHz, and is a promising platform for future application of quantum assisted sensing and readout.