We investigate a six-dimensional (6D) dual-oscillator optomechanical system, where two mechanical resonators couple to a single optical mode, and show that noise acts as a control parameter that both accelerates the route to chaos and generates riddled basins—fractal intermingling of synchronized and anti-synchronized attractors. Combining Poincar´e sections, 2D/3D phasespace projections, the full Lyapunov spectrum, Kaplan–Yorke dimension, Melnikov analysis, and Fokker–Planck diagnostics, we obtain a quantitative and self-consistent picture of noiseinduced complexity. As the laser drive increases, a Feigenbaum-type period-doubling cascade culminates in chaos and hyperchaos ( λ1 > 0; λ1, λ2 > 0 with DKY ∈ [2, 4] ), while Melnikov predictions confirm homoclinic intersections underlying global instability. Riddled-basin formation is demonstrated and quantified by a stability index σ = 0.3–0.6, (ii) fractal basin dimension DB ≈ 1.2–1.55, and (iii) basin entropy SB ≈ 0.3–0.45, all peaking in the noise-driven regime. Transverse Lyapunov exponents along the synchronized and anti-synchronized attractors remain negative (transverse stability), while transversely unstable periodic orbits embedded in the attractors provide the dynamical mechanism for riddling. A critical noise threshold Dc ≈ 0.05 is identified for attractor switching and the smearing of bifurcation structure; largest-exponent maps λ1(E, D) correlate these transitions with parameter space. Our results establish rigorous evidence for noise-modulated (hyper)chaos in high-dimensional optomechanics and offer predictive levers (detuning, coupling, and noise engineering) for controlling instability in microcavity and LIGO-type platforms, as well as enabling applications in chaos-based photonics and sensing.

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