摘要:
A laser processing apparatus 1 includes a laser light source 10, a phase modulation type spatial light modulator 20, a driving unit 21, a control unit 22, and an imaging optical system 30. The imaging optical system 30 may be a telecentric optical system. A storage unit 21A included in the driving unit stores a plurality of basic holograms corresponding to a plurality of basic processing patterns and a focusing hologram corresponding to a Fresnel lens pattern. The control unit 22 arranges in parallel two or more basic holograms selected from the plurality of basic holograms stored in the storage unit 21A, overlaps the focusing hologram with each of the basic holograms arranged in parallel to form the whole hologram, and presents the formed whole hologram to the spatial light modulator 20.
摘要:
A laser machining device is provided with a laser light source, a spatial light modulator, a driving unit, a control unit, and a condensing optical system. The control unit selects a basic hologram corresponding to each basic machining pattern included in a whole machining pattern in a workpiece from a plurality of basic holograms stored by the storage unit, and determines a display region of the basic hologram in the spatial light modulator so that the deviation of the value of “Iη/n” becomes small for the selected respective basic hologram when the intensity of a laser beam input to a display region of the basic hologram in the spatial light modulator is defined as I, the diffraction efficiency of the laser beam in the basic hologram is defined as η, and the number of condensing points in a basic machining pattern corresponding to the basic hologram is defined as n.
摘要:
A laser machining device is provided with a laser light source, a spatial light modulator, a driving unit, a control unit, and a condensing optical system. The control unit selects a basic hologram corresponding to each basic machining pattern included in a whole machining pattern in a workpiece from a plurality of basic holograms stored by the storage unit, and determines a display region of the basic hologram in the spatial light modulator so that the deviation of the value of “Iη/n” becomes small for the selected respective basic hologram when the intensity of a laser beam input to a display region of the basic hologram in the spatial light modulator is defined as I, the diffraction efficiency of the laser beam in the basic hologram is defined as η, and the number of condensing points in a basic machining pattern corresponding to the basic hologram is defined as n.
摘要:
A laser machining device 1 includes a laser light source 10, a spatial light modulator 20, a controller 22, a converging optical system 30, and a shielding member 40. The phase-modulating spatial light modulator 20 inputs a laser beam outputted from the laser light source 10, displays a hologram modulating a phase of the laser beam at each of a plurality of pixels arranged two-dimensionally, and outputs the phase-modulated laser beam. The controller 22 causes the spatial light modulator 20 to display a plurality of holograms sequentially, lets the converging optical system 30 converge the laser beam outputted from the spatial light modulator 20 at converging positions having a fixed number of M, selectively places N converging positions out of the M converging positions into a machining region 91, and machines an object to be machined 90.
摘要:
A laser machining device 1 comprises a laser light source 10, a spatial light modulator 20, a controller 22, a converging optical system 30, and a shielding member 40. The phase-modulating spatial light modulator 20 inputs a laser beam outputted from the laser light source 10, displays a hologram modulating a phase of the laser beam at each of a plurality of pixels arranged two-dimensionally, and outputs the phase-modulated laser beam. The controller 22 causes the spatial light modulator 20 to display a plurality of holograms sequentially, lets the converging optical system 30 converge the laser beam outputted from the spatial light modulator 20 at converging positions having a fixed number of M, selectively places N converging positions out of the M converging positions into a machining region 91, and machines an object to be machined 90.
摘要:
In controlling light condensing irradiation with laser light using a spatial light modulator, an incident pattern of the laser light and respective refractive indices of first and second propagation media on a propagation path are acquired, the number of light condensing points, and the light condensing position and the light condensing intensity at each light condensing point are set, an aberration condition caused by the first and second propagation media is derived, and by taking the aberration condition into account, a modulation pattern to be presented in the spatial light modulator is designed. Further, in designing the modulation pattern, a design method focusing on an effect of a phase value at one pixel is used, and in evaluating the light condensing state at the light condensing point, a propagation function that takes the aberration condition into account is employed.
摘要:
In controlling light condensing irradiation with laser light using a spatial light modulator, an incident pattern of the laser light and respective refractive indices of first and second propagation media on a propagation path are acquired, the number of light condensing points, and the light condensing position and the light condensing intensity at each light condensing point are set, an aberration condition caused by the first and second propagation media is derived, and by taking the aberration condition into account, a modulation pattern to be presented in the spatial light modulator is designed. Further, in designing the modulation pattern, a design method focusing on an effect of a phase value at one pixel is used, and in evaluating the light condensing state at the light condensing point, a propagation function that takes the aberration condition into account is employed.
摘要:
A spatial light modulation device includes a liquid crystal layer modulating a phase of incident light according to a level of an applied electric field, a temperature sensor generating a temperature signal corresponding to a temperature of the liquid crystal layer, a plurality of pixel electrodes provided for each of a plurality of pixels and applying a voltage to the liquid crystal layer, and a driving device providing a voltage to the plurality of pixel electrodes. The driving device has a nonvolatile storage element storing in advance a coefficient α included in a function expressing a correlation between a temperature change amount in the liquid crystal layer and a variation in phase modulation amount in the liquid crystal layer, and performs a calculation for correcting a level of voltage by use of a temperature indicated by the temperature signal and the coefficient α.
摘要:
A spatial light modulation device includes a liquid crystal layer modulating a phase of incident light according to a level of an applied electric field, a temperature sensor generating a temperature signal corresponding to a temperature of the liquid crystal layer, a plurality of pixel electrodes provided for each of a plurality of pixels and applying a voltage to the liquid crystal layer, and a driving device providing a voltage to the plurality of pixel electrodes. The driving device has a nonvolatile storage element storing in advance a coefficient α included in a function expressing a correlation between a temperature change amount in the liquid crystal layer and a variation in phase modulation amount in the liquid crystal layer, and performs a calculation for correcting a level of voltage by use of a temperature indicated by the temperature signal and the coefficient α.
摘要:
A spatial light modulation device includes a phase-modulation type spatial light modulator, a temperature sensor detecting a temperature of the spatial light modulator, and a control unit providing a drive signal to the spatial light modulator. The control unit has a storage unit. The storage unit stores N correction patterns created so as to correspond to N (N is an integer not less than 2) temperature values of the spatial light modulator in order to correct phase distortion of the spatial light modulator. The control unit selects one correction pattern according to a temperature value of the spatial light modulator, and generates the drive signal based on a phase pattern created by adding the one correction pattern to a desired phase pattern. Thereby, it becomes possible to suppress phase distortion according to a temperature change while suppressing a delay in operation.