Abstract: An object is irradiated with a laser light modulated by a reflection type spatial light modulator such that aberration of the laser light converged inside the object becomes a predetermined aberration or less. Therefore, aberration of the laser light generated at a position on which a converging point of the laser light is located is made as small as possible, to enhance the energy density of the laser light at that position, which makes it possible to form a modified region with a high function as a starting point for cutting. In addition, because the reflection type spatial light modulator is used, it is possible to improve the utilization efficiency of the laser light as compared with a transmissive type spatial light modulator.

Abstract: An object is irradiated with a laser light modulated by a reflection type spatial light modulator such that aberration of the laser light converged inside the object becomes a predetermined aberration or less. Therefore, aberration of the laser light generated at a position on which a converging point of the laser light is located is made as small as possible, to enhance the energy density of the laser light at that position, which makes it possible to form a modified region with a high function as a starting point for cutting. In addition, because the reflection type spatial light modulator is used, it is possible to improve the utilization efficiency of the laser light as compared with a transmissive type spatial light modulator.

Abstract: An object is irradiated with a laser light modulated by a reflection type spatial light modulator such that aberration of the laser light converged inside the object becomes a predetermined aberration or less. Therefore, aberration of the laser light generated at a position on which a converging point of the laser light is located is made as small as possible, to enhance the energy density of the laser light at that position, which makes it possible to form a modified region with a high function as a starting point for cutting. In addition, because the reflection type spatial light modulator is used, it is possible to improve the utilization efficiency of the laser light as compared with a transmissive type spatial light modulator.

Abstract: An apparatus comprises a table, a source emitting polarized laser light, a source emitting laser light, a plate changing the polarization direction of the laser light, a plate splitting the laser light into a laser light having polarization in an X direction and a laser light component having polarization in a Y direction, a plate orienting the polarization direction of the laser light to the X direction, a lens converging the laser light components, a lens arranged in parallel with the lens along the X direction and converges the laser light component, a control section controlling a device such that a converging point of the laser light component is located at a predetermined position with reference to a front face by detecting a reflected light, and a control section moving the table along a line while making the X direction substantially coincide with the line.

Abstract: A laser processing apparatus comprises a converging lens 31 for converging processing laser light and rangefinding laser light L2 toward a wafer 1, an actuator for actuating the lens 31, a shaping optical system 49 for adding astigmatism to reflected light L3 of the rangefinding laser light, a quadrant photodiode 42 for receiving the reflected light L3 and outputting voltage values corresponding to its light quantities, and a controller for regulating the actuator, and positions a converging point P2 of the rangefinding laser light L2 between a focal point P0 of the lens and the lens 31, so as to make it possible to form a modified region at a position deeper from the front face 3, thereby suppressing adverse effects due to the reflected light L3. The control is based on an arithmetic value subjected to a division by a sum of the voltage values, so as to prevent the arithmetic value from being changed by the quantity of reflected light.

Abstract: In the laser processing method, the cross-sectional form of laser light L at a converging point P is such that the maximum length in a direction perpendicular to a line to cut 5 is shorter than the maximum length in a direction parallel to the line to cut 5. Therefore, when seen from the incident direction of the laser light L, a modified region 7 formed within a silicon wafer 11 has such a shape that the maximum length in the direction perpendicular to the line to cut 5 is shorter than the maximum length in the direction parallel to the line to cut 5. Forming the modified region 7 having such a shape within the object 1 can restrain twist hackles from occurring on cut surfaces when cutting the object 1 from the modified region 7 acting as a cutting start point, thereby making it possible to improve the flatness of the cut surfaces.

Abstract: An object is irradiated with a laser light modulated by a reflection type spatial light modulator such that aberration of the laser light converged inside the object becomes a predetermined aberration or less. Therefore, aberration of the laser light generated at a position on which a converging point of the laser light is located is made as small as possible, to enhance the energy density of the laser light at that position, which makes it possible to form a modified region with a high function as a starting point for cutting. In addition, because the reflection type spatial light modulator is used, it is possible to improve the utilization efficiency of the laser light as compared with a transmissive type spatial light modulator.

Abstract: An object to be processed 1 is irradiated with a laser light L modulated by a reflection type spatial light modulator 203 such that aberration of the laser light L converged inside the object 1 becomes a predetermined aberration or less. Therefore, aberration of the laser light L generated at a position on which a converging point P of the laser light L is located is made as small as possible, to enhance the energy density of the laser light L at that position, which makes it possible to form a modified region 7 with a high function as a starting point for cutting. In addition, because the reflection type spatial light modulator 203 is used, it is possible to improve the utilization efficiency of the laser light L as compared with a transmissive type spatial light modulator. Such improvement of the utilization efficiency of the laser light L is particularly important in the case in which the modified region 7 serving as a starting point for cutting is formed in the plate-shaped object 1.

Abstract: A laser condensing optical system of the present invention includes a laser beam source which emits a laser beam, a condensing optical system which is arranged between the laser beam source and a medium and condenses the laser beam in the medium, and a laser divergence point moving unit which can move the position of a laser divergence point of the laser beam along an optical axis of the laser beam in accordance with the refractive index of the medium in which the laser beam is desired to be condensed and the distance from a surface of the medium to a position where the beam is desired to be condensed.

Abstract: An object to be processed 1 is irradiated with a laser light L modulated by a reflection type spatial light modulator 203 such that aberration of the laser light L converged inside the object 1 becomes a predetermined aberration or less. Therefore, aberration of the laser light L generated at a position on which a converging point P of the laser light L is located is made as small as possible, to enhance the energy density of the laser light L at that position, which makes it possible to form a modified region 7 with a high function as a starting point for cutting. In addition, because the reflection type spatial light modulator 203 is used, it is possible to improve the utilization efficiency of the laser light L as compared with a transmissive type spatial light modulator. Such improvement of the utilization efficiency of the laser light L is particularly important in the case in which the modified region 7 serving as a starting point for cutting is formed in the plate-shaped object 1.

Abstract: The time required for forming a modified region within an object to be processed is shortened.

Abstract: A shutter unit capable of preventing the scattering of the laser beam upon closing the optical path of the laser beam and capable of being miniaturized, and a laser processing device employing such a shutter unit. In a shutter unit 1, when the optical path of the laser beam L is opened, a rotating member 57 is rotated around an axis line ?, and an opening 61 is positioned on an optical axis ? so as to pass the laser beam L therethrough. Meanwhile, when the optical path of the laser beam L is closed, the rotating member 57 is rotated and a reflective surface 62 is positioned on the optical axis ? so as to reflect the laser beam L. Here, since the reflected laser beam L is absorbed by an optical absorption member 63, it is possible to prevent the scattering of the laser beam L when the optical path of the laser beam L is closed.

Abstract: In the laser processing method, the cross-sectional form of laser light L at a converging point P is such that the maximum length in a direction perpendicular to a line to cut 5 is shorter than the maximum length in a direction parallel to the line to cut 5. Therefore, when seen from the incident direction of the laser light L, a modified region 7 formed within a silicon wafer 11 has such a shape that the maximum length in the direction perpendicular to the line to cut 5 is shorter than the maximum length in the direction parallel to the line to cut 5. Forming the modified region 7 having such a shape within the object 1 can restrain twist hackles from occurring on cut surfaces when cutting the object 1 from the modified region 7 acting as a cutting start point, thereby making it possible to improve the flatness of the cut surfaces.

Abstract: To provide a laser processing apparatus which can converge a laser beam for processing an object to be processed at a position as close as possible to a predetermined position.

Abstract: A laser processing apparatus comprises a converging lens 31 for converging processing laser light and rangefinding laser light L2 toward a wafer 1, an actuator for actuating the lens 31, a shaping optical system 49 for adding astigmatism to reflected light L3 of the rangefinding laser light, a quadrant photodiode 42 for receiving the reflected light L3 and outputting voltage values corresponding to its light quantities, and a controller for regulating the actuator, and positions a converging point P2 of the rangefinding laser light L2 between a focal point P0 of the lens and the lens 31, so as to make it possible to form a modified region at a position deeper from the front face 3, thereby suppressing adverse effects due to the reflected light L3. The control is based on an arithmetic value subjected to a division by a sum of the voltage values, so as to prevent the arithmetic value from being changed by the quantity of reflected light.

Abstract: A laser processing apparatus which can suppress the positional fluctuation in light-converging point of laser light during laser processing is provided. On an optical path of laser light L1 connecting a beam expander 34 and a first light-transmitting hole 32 of a lens holder 29 to each other in a laser processing apparatus 20, a stop member 38 including a second light-transmitting hole 39 having the same diameter as that of the first light-transmitting hole 32 is disposed. Hence, the amount of laser light L1 cut by the surrounding part of the first light-transmitting hole 32 can substantially be eliminated, whereby the lens holder 29 can be prevented from being heated upon irradiation with the laser light L1. Also, even when the stop member 38 is heated by the laser light L1 cut by the surrounding part of the second light-transmitting hole 39, heat is prevented from being transmitted from the stop member 38 to the lens holder 29, since the stop member 38 is separated from the lens holder 29.

Abstract: To provide a laser processing apparatus which can converge a laser beam for processing an object to be processed at a position as close as possible to a predetermined position.

Abstract: A light emitting end face side front end part of an optical fiber bundle 16 is covered by a sleeve member 13 and an emitting part outer cover 14. A glass rod holding member 42, which holds a glass rod 40, is mounted to emitting part outer cover 14. Glass rod 40 is fixed to glass rod holding member 42 by means of positioning pins 44 and a light incidence end face 40i thereof opposes a light emitting end face 16o of optical fiber bundle 16. A light emitting end face 40o of glass rod 40 has a rectangular shape. The light emitting from light emitting end face 40o is made uniform in illuminance across the entirety of its cross section and the cross section thereof is shaped to a rectangular shape in the process of being propagated while being totally reflected at the boundary surface of glass rod 40.

Abstract: A laser condensing optical system of the present invention includes a laser beam source which emits a laser beam, a condensing optical system which is arranged between the laser beam source and a medium and condenses the laser beam in the medium, and a laser divergence point moving unit which can move the position of a laser divergence point of the laser beam along an optical axis of the laser beam in accordance with the refractive index of the medium in which the laser beam is desired to be condensed and the distance from a surface of the medium to a position where the beam is desired to be condensed.

Abstract: A laser condensing optical system of the present invention includes a laser beam source which emits a laser beam, a condensing optical system which is arranged between the laser beam source and a medium and condenses the laser beam in the medium, and a laser divergence point moving unit which can move the position of a laser divergence point of the laser beam along an optical axis of the laser beam in accordance with the refractive index of the medium in which the laser beam is desired to be condensed and the distance from a surface of the medium to a position where the beam is desired to be condensed.