Anti-relaxation or preservation of the tensile lattice strain is presented in a narrow Ge strip on Si epitaxially grown by chemical vapor deposition, regarding efficient near-infrared photodetection and light emission in Si photonics. In contrast to an edge-induced relaxation of a tensile strain in an ordinary Ge strip as narrow as a few microns or below, a tensile strain as high as 0.2% is not relaxed but preserved by embedding the strip entirely in Si.