We have used a nanostructure copper composite layer as the absorber for infrared radiation on superconductive YBCO bolometers. The Cu composite has the advantage of having little destructive effects on superconductive YBCO material and its deposition process is done at low temperature. The bolometer is made of 200nm thick YBCO film on 1mm thick LaAlO3 and SrTiO3 crystalline substrates, deposited using pulsed laser deposition technique. The Cu composite layers were made by decomposition of C2H2 and co sputtering of Cu target in an RF system. The layer was deposited on an insulating buffer layer of diamond like carbon (DLC). The spectral absorption of the Cu composite layer was also measured through measurements of the spectral transmission and reflection of the layer on various substrates. The control of the absorption of the composite layer versus Cu composition has been achieved and presented here. In addition, optimization of the Cu component of the absorber layer for maximum increase of the response of the detectors as well as its effects on the response characteristics of the devices are presented in this paper.