This sensor featuring plane-convex lens collimator for expanding beam and coupling, and a low frequency for light pulse modulation is introduced.

Among the reshaping systems converting a Gaussian beam to a flattop beam, the system composed of a plane-concave and a plane-convex lens, is a relatively simple structure.

The optical aberration difference between the biconvex Fresenl lens and the plane-convex Fresenl lens was investigated by designing a large aperture Fresenl lens.