Fig. 6: Trampoline design.

a Optical micrograph of a trampoline resonator. b Resonance frequency for 50 nm thick trampoline resonators of different central area side lengths. The window side length is fixed to L_w ≈ 1 mm, while the tether width is to w = 5 μm. From the measurements, a stress of 120 MPa is extracted. c Comparison between theoretical (black solid curve) and experimental thermal time constant τ_th. d Comparison between theoretical (solid curves) and measured (dark red circles) relative power responsivity. The error bar indicates the uncertainties in κ (2.7 − 4 W/(m K)), E (200 − 300 GPa), and α_th (1 − 2.2 ppm/K)¹⁶. e Allan deviation measured for a 230² μm² central area trampoline (green solid curve), driven at the onset of nonlinearities \({z}_{{{\rm{r}}}_{{\rm{c}}}}\), with low-pass filter bandwidth \({f}_{{\rm{demod}}}=2.5\,{\rm{kHz}}\), PLL bandwidth f_PLL = 500 Hz and optical input power P₀ = 11 μW. The comparison with the theoretical model is also shown (black solid curve), together with the single contributions (see main text). f Comparison between the theoretical (black solid curve) and experimentally extracted (dark red circles) NEP. For each trampoline’s central length, three different resonators were characterized in terms of NEP