This paper addresses the problem of arranging fewest possible probes to detect a hidden object in a specified region and presents a reasonable scheme for the purpose. Of special interest is the case where an object is a double-sided conic cylinder which represents the shape of the energy distribution of laser light used in the optical network. The performance of our scheme is evaluated by comparing the number of probes to that of an existing scheme, and our scheme shows a potential for reducing the number of probes. In other words, the time for detection is significantly reduced from a realistic point of view.