Abstract: A first reflection member, when light is incident, reflects a part of the light by a first reflection surface, reflects light transmitted through the first reflection surface by a second reflection surface, and emits reflected light components in an opposite direction. The second reflection member, when light emitted from the first reflection member is incident, reflects a part of the light by a first reflection surface, reflects light transmitted through the first reflection surface by a second reflection surface, and emits reflected light components. Interference fringes are formed on a screen by light reflected on the first reflection surface of the first reflection member and the second reflection surface of the second reflection member and light reflected on the second reflection surface of the first reflection member and the first reflection surface of the second reflection member.

Abstract: A collimation evaluation device includes a first reflection member, a second reflection member, a screen, and a housing. A first reflection surface of the first reflection member and a first reflection surface of the second reflection member face each other and are parallel to each other. Further, interference fringes are formed on the screen by light L12 reflected on the first reflection surface of the first reflection member and a second reflection surface of the second reflection member and light L21 reflected on a second reflection surface of the first reflection member and the first reflection surface of the second reflection member, and collimation of incident light is evaluated on the basis of a direction of the interference fringes.

Abstract: A planar object to be processed 1 comprising a hexagonal SiC substrate 12 having a front face 12a forming an angle corresponding to an off-angle with a c-plane is prepared. Subsequently, the object 1 is irradiated with pulse-oscillated laser light L along lines to cut 5a, 5m such that a pulse pitch becomes 10 ?m to 18 ?m while locating a converging point P of the laser light L within the SiC substrate 12. Thereby, modified regions 7a, 7m to become cutting start points are formed within the SiC substrate 12 along the lines 5a, 5m.

Abstract: A planar object to be processed 1 comprising a hexagonal SiC substrate 12 having a front face 12a forming an angle corresponding to an off-angle with a c-plane is prepared. Subsequently, the object 1 is irradiated with pulse-oscillated laser light L along lines to cut 5a, 5m such that a pulse pitch becomes 10 ?m to 18 ?m while locating a converging point P of the laser light L within the SiC substrate 12. Thereby, modified regions 7a, 7m to become cutting start points are formed within the SiC substrate 12 along the lines 5a, 5m.

Abstract: A planar object to be processed 1 comprising a hexagonal SiC substrate 12 having a front face 12a forming an angle corresponding to an off-angle with a c-plane is prepared. Subsequently, the object 1 is irradiated with pulse-oscillated laser light L along lines to cut 5a, 5m such that a pulse pitch becomes 10 ?m to 18 ?m while locating a converging point P of the laser light L within the SiC substrate 12. Thereby, modified regions 7a, 7m to become cutting start points are formed within the SiC substrate 12 along the lines 5a, 5m.