Related papers: Robustness Analysis and Controller Design of Arm-l…
This paper proposes new practical design tools for the robust motion control systems based on disturbance observer (DOB). Although DOB has long been used in several motion control applications, it has insufficient analysis and design tools.…
High quality factor ($Q$) nanomechanical resonators have received a lot of attention for sensor applications with unprecedented sensitivity. Despite the large interest, few investigations into the frequency stability of high-$Q$ resonators…
Achieving precise and adjustable control over laser frequency is an essential requirement in numerous applications such as precision spectroscopy, quantum control, and sensing. In many such applications it is desired to stabilize a laser…
To achieve sub-picometer sensitivities in the millihertz band, laser interferometric inertial sensors rely on some form of reduction of the laser frequency noise, typically by locking the laser to a stable frequency reference, such as the…
We report on the development, implementation, and characterization of digital controllers for laser frequency stabilization as well as intensity stabilization and control. Our design is based on the STEMlab (originally Red Pitaya) platform.…
We actively stabilize the harmonic oscillation frequency of a laser-cooled atomic ion confined in a rf Paul trap by sampling and rectifying the high voltage rf applied to the trap electrodes. We are able to stabilize the 1 MHz atomic…
We stabilized the frequencies of two independent Nd:YAG lasers to two adjacent longitudinal modes of a high-finesse Fabry-P\'erot resonator and obtained a beat frequency instability of 6.3 mHz at an integration time of 40 s. Referred to a…
We report on the development of a frequency modulatable 795 nm semiconductor laser based on self-injection locking to a high quality factor whispering gallery mode microresonator. The laser is characterized with residual amplitude…
Frequency responses of multi-degree-of-freedom mechanical systems with weak forcing and damping can be studied as perturbations from their conservative limit. Specifically, recent results show how bifurcations near resonances can be…
Sensing via a mechanical frequency shift is a powerful measurement tool, and, therefore, understanding and mitigating frequency noise affecting mechanical resonators is imperative. Thermomechanical noise fundamentally limits mechanical…
The stability analysis of elastic rings subjected to various loading conditions is examined, focusing on stable and unstable configurations. The harmonic balance method is employed to investigate the stability range under different loading…
This work provides formal safety guarantees for control systems with disturbance. A disturbance observer-based robust safety-critical controller is proposed, that estimates the effect of the disturbance on safety and utilizes this estimate…
Advanced gravitational wave interferometric detectors will operate at their design sensitivity with nearly 1MW of laser power stored in the arm cavities. Such large power may lead to the uncontrolled growth of acoustic modes in the test…
Divergence and vorticity damping, which operate upon horizontal divergence and relative vorticity, are explicit diffusion mechanisms used in dynamical cores to ensure stability. To avoid numerical blow-up from excessively strong diffusion,…
Understanding simplicity biases in deep learning offers a promising path toward developing reliable AI. A common metric for this, inspired by Boolean function analysis, is average sensitivity, which captures a model's robustness to…
Ultraviolet (UV) diode lasers are widely used in many photonics applications. But their frequency stabilization schemes are not as mature as frequency-doubling lasers, mainly due to some limitations in the UV spectral region. Here we…
Wide-area control is an effective mean to reduce inter-area oscillations of large power systems. Its dependence on communication of remote measurement signals makes the closed-loop system vulnerable to cyber attacks. This paper develops a…
Self-injection locking of a diode laser to a high-quality-factor microresonator is widely used for frequency stabilization and linewidth narrowing. We constructed several microresonator-based laser sources with measured instantaneous…
In this paper we describe that the optically pumped frequency standards can have frequency stability beyond the quantum noise limit by detecting the Ramsey resonance through the squeezed light. In this paper we report that instead of…
A recent proposal describes space based gravitational wave (GW) detection with optical lattice atomic clocks [Kolkowitz et. al., Phys. Rev. D 94, 124043 (2016)] [1]. Based on their setup, we propose a new measurement method for…