Object detecting device and information acquiring device

An object detecting device, comprising

• an information acquiring device which acquires information on a target area using light,
• the information acquiring device including:
• a laser light source;
• a diffractive optical element which is disposed in such a direction as to be away from an optical axis of the laser light source;
• a photodetector which is disposed to face the diffractive optical element with respect to the optical axis;
• and
• an optical path separating portion which guides laser light emitted from the laser light source to the diffractive optical element, and guides the laser light reflected on the diffractive optical element to the photodetector, wherein
• the diffractive optical element irradiates the target area with the laser light having a predetermined pattern, and
• the photodetector receives a part of the laser light diffracted and reflected on the diffractive optical element.