Abstract: The present invention provides a laser processing method comprising the steps of attaching a protective tape 25 to a front face 3 of a wafer 1a, irradiating a substrate 15 with laser light L while employing a rear face of the wafer 1a as a laser light entrance surface and locating a light-converging point P within the substrate 15 so as to form a molten processed region 13 due to multiphoton absorption, causing the molten processed region 13 to form a cutting start region 8 inside by a predetermined distance from the laser light entrance surface along a line 5 along which the object is intended to be cut in the wafer 1a, attaching an expandable tape 23 to the rear face 21 of the wafer 1a, and expanding the expandable tape 23 so as to separate a plurality of chip parts 24 produced upon cutting the wafer 1a from the cutting start region 8 acting as a start point from each other.

Abstract: A sensor prevents automobile crashes by collecting information such as a distance between automobiles, speed, and acceleration by utilizing a phenomenon that a photonic quantum ring laser emits light rays having different wavelengths associated with varying angles of the radiation from the photonic quantum ring. The sensor for preventing automobile crashes includes a photonic quantum ring laser array emitting lasing light beams having different wavelengths according to the view angle, a reflection unit for reflecting the light beams oscillated from the photonic quantum ring laser array, and a detection unit for detecting the light beams reflected by the reflection unit.