Laser light irradiating device

Patent metadata

Field	Value
Publication number	US-11465235-B2
Application number	US-201716343034-A
Country	US
Kind code	B2
Filing date	Oct 5, 2017
Priority date	Oct 19, 2016
Publication date	Oct 11, 2022
Grant date	Oct 11, 2022

Abstract

There is provided a laser light irradiating device that includes a spatial light modulator configured to modulate laser light output from a laser light source according to a phase pattern and emit the modulated laser light, an objective lens configured to converge the laser light emitted from the spatial light modulator onto the object, a focusing lens arranged between the spatial light modulator and the objective lens in an optical path of the laser light and configured to focus the laser light, and a slit member arranged at a focal position on a rear side of the focusing lens in the optical path of the laser light and configured to block a part of the laser light.

First claim

The invention claimed is:

1. A laser light irradiating device configured to irradiate an object with laser light along a first direction, the laser light irradiating device comprising:
a laser light source configured to output the laser light;
a spatial light modulator configured to modulate the laser light output from the laser light source according to a phase pattern and emit the laser light;
an objective lens configured to converge the laser light emitted from the spatial light modulator onto the object;
a focusing lens arranged between the spatial light modulator and the objective lens in an optical path of the laser light and configured to focus the laser light; and
a slit member arranged at a focal position on a rear side of the focusing lens in the optical path of the laser light and configured to block a part of the laser light, wherein
the phase pattern includes a first pattern in which a part of the laser light entering a pupil plane of the objective lens is modulated and a second pattern in which a remainder of the laser light is modulated,
the second pattern includes a diffraction lattice pattern for branching the remainder of the laser light into a plurality of diffracted light along a second direction crossing the first direction, and
the slit member blocks the diffracted light with a slit.

2. The laser light irradiating device according to claim 1 , wherein
the slit is formed so as to be relatively longer in the first direction than in the second direction.

3. The laser light irradiating device according to claim 1 , wherein
the first pattern includes another diffraction lattice pattern for branching the part of the laser light into a plurality of other diffracted light along the first direction.

4. The laser light irradiating device according to claim 3 , wherein
a size of the slit in the first direction is larger than a sum of a beam size of the other diffracted light at the focal position and a branching interval of the other diffracted light at the focal position, and
a size of the slit in the second direction is larger than a beam size of the diffracted light at the focal position.

5. The laser light irradiating device according to claim 4 , wherein
the branching interval is an interval of the other diffracted light of ±one-order in the first direction.

6. The laser light irradiating device according to claim 4 , wherein
the size of the slit in the second direction is smaller than a maximum diffraction distance F expressed by the following formula (1) in which a focal length of the focusing lens is represented by f, a wavelength of the laser light is represented by λ, and a pixel size of the spatial light modulator is represented by x SLM .

[

Formula
⁢

1

]

F
=

2
⁢
f
×

tan
⁡
(

sin

-
1

(

m
⁢
λ

2
⁢

x
SLM

)

)

(
1
)

7. The laser light irradiating device according to claim 4 , wherein
the size of the slit in the first direction is smaller than an interval of the other diffracted light of ±three-order at the focal position.

8. The laser light irradiating device according to claim 3 , wherein
the another diffraction lattice pattern includes a plurality of groove patterns along the second direction, and
the diffraction lattice pattern includes a plurality of groove patterns along the first direction.

9. The laser light irradiating device according to claim 1 , wherein
the spatial light modulator includes a liquid crystal layer configured to display the phase pattern,
the liquid crystal layer includes a circular effective region in a region in which the laser light is incident and an annular non-effective region outside the effective region,
the first pattern is displayed in the effective region and modulates the part of the laser light, and
the second pattern is displayed in the non-effective region and modulates the remainder of the laser light.

10. A laser light irradiating device configured to irradiate an object with laser light along a first direction, the laser light irradiating device comprising:
a laser light source configured to output the laser light;
a spatial light modulator configured to modulate the laser light output from the laser light source according to a phase pattern and emit the laser light;
an objective lens configured to converge the laser light emitted from the spatial light modulator onto the object;
a focusing lens arranged between the spatial light modulator and the objective lens in an optical path of the laser light and configured to focus the laser light; and
a slit member arranged at a focal position on a rear side of the focusing lens in the optical path of the laser light and configured to block a part of the laser light, wherein
the spatial light modulator includes a liquid crystal layer configured to display the phase pattern,
the liquid crystal layer includes an effective region in which a part of the laser light entering a pupil plane of the objective lens is incident and a non-effective region in which remainder of the laser light is incident, and
the slit member blocks light modulated in the non-effective region with a slit.

Assignees

• Hamamatsu Photonics Kk

Inventors

• Okuma Junji

Classifications

• H10P72/0436

  mainly by radiation · CPC title

• G02B5/18

  Diffraction gratings {(holographic optical elements G02B5/32, G03H; integrally combined with optical fibres G02B6/02057; for coupling light guides G02B6/34; integrally combined with optical integrated light guides G02B6/12; grating systems G02B27/44)} · CPC title

• G02F1/133723

  Polyimide, polyamide-imide · CPC title

• G02B1/00

  Optical elements characterised by the material of which they are made; Optical coatings for optical elements · CPC title

• G02B1/041

  Lenses · CPC title