Opto acoustical gravitational bar detector with cryogenic mirrors
  Enhancing of sensitivity of the opto-acoustical gravitational wave (GW) antenna OGRAN installed in the underground facilities of Baksan Neutrino Observatory is analyzed. Calculations are presented showing a sensitivity improving on two orders of value after a cooling the solid body acoustical part of the antenna to the nitrogen temperature. A possibility of keeping of the same optical scheme of the antenna at low temperature is discussed. Design of modernized construction for cryogenic version of the antenna OGRAN is described. Test experiments with cooled pilot model carrying cryogenic mirrors illuminated by the optical pump up to 0.5 W are presented. 
V.V. Kulagin, S.I. Oreshkin, S.M. Popov, V.N. Rudenko, M.N. Skvortsov,   I.S. Yudin
gr-qc physics.ins-det