We report the experimental observation of two bottleneck phenomena near the high frequency boundary of the inertial range on the spectrum of the turbulence in the system of capillary waves on the surface of liquid hydrogen and superfluid helium driven by a harmonic force. Both effects are manifested as a local maximum on the spectrum of pair correlation function of the surface elevation. The first phenomenon has been observed on the steady state spectra of capillary turbulence on the surface of superfluid helium. The other one has been observed in experiments with liquid hydrogen; it can be seen only during reorganization of the turbulent cascade due to a generation of waves below the driving frequency. Despite the similarities between two effects we argue that they have different underlying nature. While the bottleneck on the surface of superfluid helium is caused by the detuning between the high-frequency harmonics and the resonant frequencies of the surface oscillation in a finite container [1], the bottleneck on the surface of liquid hydrogen can be associated with a distortion of the Kolmogorov-Zakharov spectrum caused by the viscous damping [2].

1. L.V. Abdurakhimov et al., JEPT Letters 91(6), 271 (2010)
2. G.E. Falkovich and A.V. Shafarenko, Sov. Phys. JETP 67, 1393 (1988)