Resonance Lineshapes of a Driven Damped Harmonic Oscillator

quality factor Q =

ω

0

/2γ

2.5

The plots show (solid lines) the frequency dependence of the amplitude, the phase, the in-phase component, and the quadrature component of a driven damped harmonic oscillator. The variable parameter is the quality factor

Q

of the oscillator, that is, the ratio of the oscillator's resonance frequency

ω

0

to its damping constant

γ

. The (normalized) lineshapes are presented in dimensionless frequency units, giving the representations a universal character that can be applied to any driven oscillator (mechanics, electronics, optics, etc.). The plots also show (dashed lines) the Lorentzian lineshapes obtained in the high-

Q

limit when

ω

0

>>γ

.