2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/188913A relatively simple method of overcoming the Standard Quantum Limit in the next-generation Advanced LIGO gravitational wave detector is considered. It is based on the quantum variational measurement with a single short (a few tens of meters) filter cavity. Estimates show that this method allows to reduce the radiation pressure noise at low frequencies ($<100 \mathrm{Hz}$) to the level comparable with or smaller than the low-frequency noises of non-quantum origin (mirrors suspension noise, mirrors internal thermal noise, and gravity gradients fluctuations).12 pages, 4 figures; NSNS SNR estimates added; misprints correctedGeneral Relativity and Quantum Cosmologytext