An embodiment of the present invention provides an optical probe, comprising: a first sleeve in which a lens is contained, the first sleeve having a light transmission aperture from which a exciting light enters the first sleeve; a second sleeve movably engaged with the first sleeve and having a detection window from which the exciting light having passed through the first sleeve and focused by the lens exits the optical probe, the second sleeve being capable of moving with respect to the first sleeve from a first detection position to a second detection position or from the second detection position to the first detection position; and a positioning member configured to position the second sleeve at the first detection position or the second detection position with respect to the first sleeve.