Sensor head

A sensor head of a sensor for measuring a position of a measurement object, the sensor head comprising:

• a diffractive lens emitting a light incident from a light source side to a measurement object side along an optical axis and generating chromatic aberration on the light;
• an objective lens disposed on the measurement object side with respect to the diffractive lens, gathering light incident from a diffractive lens side to emit the light to the measurement object side, and emitting the light incident from the measurement object side to the diffractive lens side along the optical axis;
• and
• a case having a space formed inside, which houses at least the diffractive lens and the objective lens,
• wherein the case comprises a first case part and a second case part that respectively have a substantially cylindrical shape with the optical axis as a central axis and are opened at an end part, and a connection member that has a substantially annular shape with the optical axis as a central axis,
• the diffractive lens is disposed inside the first case part,
• the objective lens is disposed inside the second case part,
• a male thread part is formed on an outer circumferential surface of the connection member, and
• the first case part and the second case part are connected to each other by screwing female thread parts respectively formed on inner circumferential surfaces of the first case part and the second case part to the male thread part of the connection member.