A cavity optomechanical locking scheme based on the optical spring effect

Abstract

We present a novel locking scheme for active length-stabilization and frequency detuning of a cavity optomechanical device based on the optical spring effect. The error signal is generated by utilizing the position measurement of a thermally driven intra-cavity nanomechanical device and employing its detuning-dependent frequency shift caused by the dispersive coupling to the cavity field. The scheme neither requires external modulation of the laser or the cavity nor does it demand for additional error signal readout, rendering its technical implementation rather simple for a large variety of existing optomechanical devices. Specifically, for large-linewidth microcavities or in situations where other locking schemes appear unfavorable conceptually or are hard to realize technically, the optical spring lock represents a potential alternative for stabilizing the cavity length. We explain the functional principle of the lock and characterize its performance in terms of bandwidth and gain profile.

Efficient Optomechanical Mode-Shape Mapping of Micromechanical Devices

“…A standard approach to track a resonance is a phase-lock loop (PLL) [ 6 , 27 ]. Here, it is a software-implemented PI-controller in LabVIEW (note that it is also possible to perform this task using the digital signal processor in the lock-in amplifier [ 28 , 29 ], which can further improve the operation speed) in combination with digital demodulation in the LIA.…”

Achievements and perspectives of optical fiber Fabry–Perot cavities

“…Aside from electronic locking also other mechanisms for example through the optomechanical spring effect of an integrated membrane [32] or via thermal locking [6,33] can be realized. The latter is based on a self-locking mechanism, where thermal drifts caused by the heat-induced through the intra-cavity field lead to a stabilization of the cavity resonance.…”

“…FFPCs have been used in optomechanical experiments because of their ability to realize miniaturized cavities corresponding to small that at the same time still allow for a simple integration of mechanical elements, because of the accessible cavity volume. Most of the realizations using FFPCs can be attributed to the so-called membranein-the-middle (MIM) type experiments [26,32,77,78] (see Fig. 9a), where a partially transmitting element divides the cavity into two sub-cavities.…”

“…The optical field extends on both sides of the mechanical oscillator, which is clamped outside the mode volume of the optical mode. Examples for this geometry are [26,32,77,78]. b Depicts a setup using density waves in liquid helium as the mechanical resonance as demonstrated in [79,80].…”

“…The two sideband resolved realizations [vi, vii] use density waves in liquid helium as the mechanical resonance [79,80]. The conventional membrane realizations [i-iv] are [26,32,77,78] and the experiment using nanowire as the mechanical resonator [81]. c Shows the performance of the different experiments in terms of the mechanical and optical loss rates and in relation to g 0 different cavity geometry even the realization of a photonic flywheel, which using dissipative Kerr solitons may lead to the FFPC-based frequency comb devices [93] (see Fig.…”