Abstract:
A wavelength conversion element includes a crystal having a periodically poled structure in which polarization is inverted with an inversion period Λ along a z-axis which is an input axis of a light pulse. The wavelength conversion element is configured to generate an output light pulse converted to have an output frequency f(x) corresponding to the inversion period Λ(x) at each position x by change of the inversion period Λ according to the position x, and when a target frequency linearly changing with the position x is set to fT(x)=b+ax, a frequency width of the output frequency is set to δf(x), and the output frequency is set to f(x)=fT(x)+α(x), the output frequency is set to coincide with the target frequency within a range satisfying a condition |α(x)|≦δf(x).
Abstract:
In an aberration-correcting method according to an embodiment of the present invention, in an aberration-correcting method for a laser irradiation device 1 which focuses a laser beam on the inside of a transparent medium 60, aberration of a laser beam is corrected so that a focal point of the laser beam is positioned within a range of aberration occurring inside the medium. This aberration range is not less than n×d and not more than n×d+Δs from an incidence plane of the medium 60, provided that the refractive index of the medium 60 is defined as n, a depth from an incidence plane of the medium 60 to the focus of the lens 50 is defined as d, and aberration caused by the medium 60 is defined as Δs.
Abstract:
A control apparatus includes a lens, an SLM presenting a modulation pattern on a modulation plane and outputting modulated light L2 for forming light spots P1 and P2 on a pupil plane of the lens, an imaging device imaging a fringe pattern image formed on a focal plane of the lens and generating image data Da indicating the fringe pattern image, a calculation unit calculating at least one kind of parameter among an intensity amplitude, a phase shift amount, and an intensity average from the image data Da, an analysis unit obtaining a deviation in relative positions of an optical axis of the lens and a reference coordinate of the modulation plane based on the parameter, and a changing unit changing an origin position of the reference coordinate so that the deviation in the relative positions is decreased.
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 optical module (1A) includes a polarization beam splitter (10A) having a light splitting surface (11), polarization elements (20, 40), and respectively arranged on an optical path of a first polarization component (L2) transmitted through the light splitting surface (11) and an optical path of a second polarization component (L4) reflected by the light splitting surface (11), a reflective SLM (30) that modulates and reflects the first polarization component (L2) passing through the polarization element (20), and a reflective SLM (50) that modulates and reflects the second polarization component (L4) passing through the polarization element (40). The first modulation light (L3) passing through the polarization element (20) again and then reflected by the light splitting surface (11) and the second modulation light (L5) passing through the polarization element (40) again and then transmitted through the light splitting surface (11) are combined with each other.
Abstract:
The present invention relates to a phase modulating apparatus capable of highly accurately and easily correcting the phase modulation characteristic of a reflective electric address spatial light modulator even when a condition of input light is changed. In the LCOS phase modulating apparatus, an input unit inputs the condition of the input light, and a processing unit sets an input value for each pixel. A correction value deriving unit determines a correction condition according to the condition of the input light. A control input value converting unit converts the input value set for each pixel into a corrected input value based on the correction condition. An LUT processing unit converts the corrected input value into a voltage value, and drives each pixel by using a drive voltage equivalent to the converted voltage value.