We demonstrate a simple and robust geometry for optical trapping in vacuum of a single nanoparticle based on a parabolic mirror and the optical gradient force, and we demonstrate rapid parametric feedback cooling of all three motional degrees of freedom from room temperature to a few mK. A single laser at 1550nm, and a single photodiode, are used for trapping, position detection, and cooling for all three dimensions. Particles with diameters from 26nm to 160nm are trapped without feedback to 10 $^{-5}$ mbar and with feedback engaged the pressure is reduced to 10 $^{-6}$ mbar. Modifications to the harmonic motion in the presence of noise and feedback are studied, and an experimental mechanical quality factor $>4\times 10^7$ is estimated.We demonstrate a simple and robust geometry for optical trapping in vacuum of a single nanoparticle based on a parabolic mirror and the optical gradient force, and we demonstrate rapid parametric feedback cooling of all three motional degrees of freedom from room temperature to a few mK. A single laser at 1550nm, and a single photodiode, are used for trapping, position detection, and cooling for all three dimensions. Particles with diameters from 26nm to 160nm are trapped without feedback to 10$^{-5}$mbar and with feedback engaged the pressure is reduced to 10$^{-6}$mbar. Modifications to the harmonic motion in the presence of noise and feedback are studied, and an experimental mechanical quality factor $>4\times 10^7$ is estimated.

Mar 9, 20164 citations

Trap Effects

Gerard T. Higgins

Springer thesesJan 1, 20190 citations

Feedback

Alberto Barchielli, Matteo Gregoratti

Lecture notes in physicsJan 1, 20090 citations

Hardware-in-the-loop simulation research on cooling effect of different modulated waveform signals with vacuum optical trap parameter feedback

Zhanming Hu, Huibing Han, Haonan Liu +4 more

Vacuum optical trap is a technology that captures and manipulates particles in a near-vacuum environment by means of laser mechanical effects. It is an ideal platform for precision measurement with high quality factor. Due to its low environmental damping, vacuum optical traps require feedback cooling to reduce the equivalent temperature of particle centroid motion to prevent particle escape. Parametric feedback cooling is a mainstream solution to achieve stable trapping of particles in optical traps. Monte Carlo method and finite difference method were used to simulate the displacement fluctuation of the microsphere without feedback, and the FPGA circuit was used to output control signals with different waveforms to test the feedback cooling effect. Under the premise of reaching mK cooling level, square wave control signals have advantages in fast feedback cooling, and sine wave control signals have advantages in maintaining phase matching.Vacuum optical trap is a technology that captures and manipulates particles in a near-vacuum environment by means of laser mechanical effects. It is an ideal platform for precision measurement with high quality factor. Due to its low environmental damping, vacuum optical traps require feedback cooling to reduce the equivalent temperature of particle centroid motion to prevent particle escape. Parametric feedback cooling is a mainstream solution to achieve stable trapping of particles in optical traps. Monte Carlo method and finite difference method were used to simulate the displacement fluctuation of the microsphere without feedback, and the FPGA circuit was used to output control signals with different waveforms to test the feedback cooling effect. Under the premise of reaching mK cooling level, square wave control signals have advantages in fast feedback cooling, and sine wave control signals have advantages in maintaining phase matching.

International Conference on Signal Processing and Communication Technology (SPCT)Apr 6, 20230 citations

Feedback

Marc Abrahams

The New ScientistAug 1, 20230 citations

Measurement and feedback for cooling heavy levitated particles in low-frequency traps

L. S. Walker, Gordon R. M. Robb, Andrew J. Daley

We consider a possible route to ground-state cooling of a levitated nanoparticle, magnetically trapped by a strong permanent magnet, using a combination of measurement and feedback. The trap frequency of this system is much lower than those involving trapped ions or nanomechanical resonators. Minimization of environmental heating is therefore challenging as it requires control of the system on a timescale comparable to the inverse of the trap frequency. We show that these traps are an excellent platform for performing optimal feedback control via real-time state estimation, for the preparation of motional states with measurable quantum properties.We consider a possible route to ground-state cooling of a levitated nanoparticle, magnetically trapped by a strong permanent magnet, using a combination of measurement and feedback. The trap frequency of this system is much lower than those involving trapped ions or nanomechanical resonators. Minimization of environmental heating is therefore challenging as it requires control of the system on a timescale comparable to the inverse of the trap frequency. We show that these traps are an excellent platform for performing optimal feedback control via real-time state estimation, for the preparation of motional states with measurable quantum properties.

arXiv:1903.10470Physical Review ADec 12, 201910 citations

^{-5}

mbar and with feedback engaged the pressure is reduced to 10

^{-6}

mbar. Modifications to the harmonic motion in the presence of noise and feedback are studied, and an experimental mechanical quality factor

>4\times 10^7

is estimated.