Figure 2
From: Low-power phonon lasing through position-modulated Kerr-type nonlinearity
(a) Output noise power spectral density (PSD) for different values of gnl. The magnitude of \({S}_{out}=\sqrt{\langle \delta {\alpha }^{out\dagger }\delta {\alpha }^{out}\rangle }\) reveals the amplitude of the mechanical resonator, detected at the output for a given frequency. (b) Values of the output spectrum (in (a)) at the resonance (\(\omega =-\,{\rm{\Delta }}\)). (c) Amplifier’s gain (see Eq. (16)) versus αin, for different values of gnl. (d) Cavity frequency shift \({{\rm{\Delta }}}_{nl}=\tilde{{\rm{\Delta }}}-{{\rm{\Delta }}}_{0}\) versus αin. The driving strength in (a,b) is \({\alpha }^{in}=2\times {10}^{2}\sqrt{{\omega }_{m}}\), with \({n}_{th}={n}_{\alpha }=1\) for (a). The other parameters are the same as in Fig. 1.
