The invention relates to the hemispherical and spherical two-photon response semiconductor photodetector for the ultrashort optical pulse measurement system, the optoelectronic integrated system and the optical communication system. The hemispherical two-photon response semiconductor photodetector comprises the semiconductor hemisphere (1), the metal electrode pairs (2, 2') and the micro lens (3), and its features are: the radius of the semiconductor hemisphere (1) is less than the work distance of the micro lens (3), and the sphere center of the semiconductor hemisphere (1) locates in the focus of the micro lens (3), and the metal electrode pairs (2, 2') locates in the plane of the semiconductor hemisphere (1), and the incident parallel light (4) passes the focus of the micro lens (3), incident vertical to the spherical surface of the semiconductor hemisphere (1), and going ahead along the radius direction, and finally the focus of the focused beam falls at the spherical center, and imposing the DC voltage to the metal electrode pairs (2, 2'), by the measurement of the optical current, to achieve a relative measurement of the incident light power.