Is a resonator linewidth affected by its nonlinearity ?

[gagio]

Hello everybody,

I am new on this website and I hoppe I choosed the right section.

If I am correct, the linewidth of a resonator 2Δf must be defined by the product of its damping rate γ and its resonance frequency f :
2Δf = 2.γ.f

In my case, I want to consider a strongly nonlinear oscillator, the frequency varies a lot with the oscillation amplitude. I already know that this nonlinearity will increase a lot the linewidth of the power spectra.

I wonder if such large the nonlinearity can also affect the linewidth of the oscillator when it is not excited (it becomes a resonator), and then be higher than 2.γ.f.

If you have seen this problem in any type of system I would be very happy :)

Thank you very much in advance !

 

[AndyW]

Hello and welcome to the forum!

Your understanding of the linewidth of a resonator is correct. It is indeed defined by the product of its damping rate and resonance frequency. In the case of a strongly nonlinear oscillator, the frequency will vary with the oscillation amplitude, which can affect the linewidth of the power spectra.

To answer your question, yes, the nonlinearity can also affect the linewidth of the oscillator when it is not excited and becomes a resonator. In fact, the nonlinearity can increase the linewidth beyond the expected value of 2Δf = 2γf. This is because the nonlinearity introduces additional frequency components in the system, which can contribute to the overall linewidth.

This phenomenon has been observed in various systems, such as optical cavities, microelectromechanical systems (MEMS), and superconducting resonators. The specific effects of nonlinearity on the linewidth will depend on the specific system and its parameters.

I hope this helps answer your question. Good luck with your research!