US 11,626,709 B2Granted

Light-emitting device and production method for same

AssigneeHamamatsu Photonics K.K.

InventorsKazuyoshi Hirose, Yoshitaka Kurosaka, Yuu Takiguchi, Takahiro Sugiyama

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Abstract

The embodiment relates to a light-emitting device in which a positional relationship between a modified refractive index region's gravity-center position and the associated lattice point differs from a conventional device, and a production method. In this device, a stacked body including a light-emitting portion and a phase modulation layer optically coupled to the light-emitting portion is on a substrate. The phase modulation layer includes a base layer and plural modified refractive index regions in the base layer. Each modified refractive index region's gravity-center position locates on a virtual straight line passing through a corresponding reference lattice point among lattice points of a virtual square lattice on the base layer's design plane. A distance between the reference lattice point and the modified refractive index region's gravity center along the virtual straight line is individually set such that this device outputs light forming an optical image.

Claims17

Dependent claims

A production method for a light-emitting device that includes a substrate having a main surface and outputs light to form an optical image in at least one direction of a normal direction of the main surface and an inclination direction inclined with respect to the normal direction, the production method comprising:

a preparing step of preparing the substrate;
and
a stacking step of providing a light-emitting portion and a phase modulation layer optically coupled to the light-emitting portion on the substrate,
wherein the stacking step comprises:
a first step of providing a base layer on the substrate, the base layer having a predetermined refractive index and constituting a part of the phase modulation layer;
and
a second step of providing a plurality of modified refractive index regions in the base layer provided in the first step, the plurality of modified refractive index regions having a refractive index different from the refractive index of the base layer, and
the second step comprises:
a first setting step of setting a virtual square lattice, defined by a plurality of first reference lines arranged in parallel to each other and a plurality of second reference lines arranged in parallel to each other in a state of being orthogonal to the plurality of first reference lines, on a design plane of the base layer orthogonal to the normal direction;
a second setting step of specifying an intersection between any of the plurality of first reference lines and any of the plurality of second reference lines as a reference lattice point serving as an arrangement reference of a modified refractive index region, selected from among the plurality of modified refractive index regions, among lattice points of the square lattice;
a third setting step of setting a virtual straight line on which a gravity center of the selected modified refractive index region is arranged on the design plane of the base layer, the virtual straight line passing through the reference lattice point and having a predetermined tilt angle with respect to the first reference line or the second reference line orthogonal at the reference lattice point;
a fourth setting step of setting a distance on the virtual straight line from the reference lattice point to the gravity center of the selected modified refractive index region on the design plane of the base layer such that at least a part of the light to form the optical image is outputted;
and
a region formation step of performing the second to fourth setting steps for each of the plurality of modified refractive index regions and forming the plurality of modified refractive index regions in the base layer.

11 more elements

A light-emitting device that outputs light to form an optical image in at least one direction of a normal direction of a main surface and an inclination direction inclined with respect to the normal direction, the light-emitting device comprising:

a substrate having the main surface;
a light-emitting portion provided on the substrate;
and
a phase modulation layer provided on the substrate in a state of being optically coupled to the light-emitting portion, the phase modulation layer including a base layer having a predetermined refractive index, and a plurality of modified refractive index regions having a refractive index different from the refractive index of the base layer, wherein
the plurality of modified refractive index regions of the phase modulation layer are arranged at predetermined positions in the base layer according to an arrangement pattern for formation of the optical image,
the arrangement pattern is defined such that,
where a virtual square lattice configured by M1 (an integer of one or more)×N1 (an integer of one or more) unit constituent regions R each having a square shape is set on an X-Y plane in an XYZ orthogonal coordinate system defined by a Z-axis coinciding with the normal direction of the main surface and the X-Y plane including an X-axis and a Y-axis orthogonal to each other and coinciding with one surface of the phase modulation layer including the plurality of modified refractive index regions,
a gravity center G of a modified refractive index region positioned in a unit constituent region R(x, y) is separated from a lattice point O(x, y), which is a center of the unit constituent region R(x, y), by a distance r in the unit constituent region R(x, y) on the X-Y plane specified by a coordinate component x (an integer of from 1 to M1) in an X-axis direction and a coordinate component y (an integer of from 1 to N1) in a Y-axis direction, and a vector from the lattice point O(x, y) to the gravity center G is directed in a specific direction,
coordinates (ξ, η, ζ) in the XYZ orthogonal coordinate system satisfy relationships expressed by following Formulas (1) to (3) with respect to spherical coordinates (d1, θtilt, θrot) defined by a length d1 of a radius, a tilt angle θtilt from the Z-axis, and a rotational angle θrot from the X-axis specified on the X-Y plane,
ξ=d1 sin θtilt cos θrot (1)
η=d1 sin θtilt sin θrot (2)
ζ=d1 cos θtilt (3)
where a beam pattern corresponding to the optical image is a set of bright spots directed in directions defined by the angles θtilt and θrot, the angles θtilt and θrot are converted to a coordinate value kx, which is a normalized wave number defined by following Formula (4), on a Kx-axis corresponding to the X-axis and a coordinate value ky, which is a normalized wave number defined by following Formula (5), on a Ky-axis corresponding to the Y-axis and orthogonal to the Kx-axis,
k
x
=
a
λ
⁢
sin
⁢
⁢
θ
tilt
⁢
cos
⁢
⁢
θ
rot
(
4
)
k
y
=
a
λ
⁢
sin
⁢
⁢
θ
tilt
⁢
sin
⁢
⁢
θ
rot
(
5
)
a:
Lattice constant of virtual square lattice
λ:
Oscillation wavelength
a specific wave number range including the beam pattern is constituted by M2 (an integer of one or more)×N2 (an integer of one or more) image regions FR each having a square shape in a wave number space defined by the Kx-axis and the Ky-axis,
in the wave number space, a complex amplitude F(x, y), obtained by performing a two-dimensional inverse Fourier transform of each of image regions FR (kx, ky) specified by a coordinate component kx (an integer of from 0 to M2−1) in a Kx-axis direction and a coordinate component ky (an integer of from 0 to N2−1) in a Ky-axis direction into the unit constituent region R(x, y) on the X-Y plane, is given by following Formula (6), using j as an imaginary unit,
F
⁡
(
x
,
y
)
=
∑
k
x
=
0
M
⁢
⁢
2
-
1
⁢
∑
k
y
=
0
N
⁢
⁢
2
-
1
⁢
FR
⁡
(
k
x
,
k
y
)
⁢
exp
⁡
[
j
⁢
⁢
2
⁢
π
⁡
(
k
x
M
⁢
⁢
2
⁢
x
+
k
y
N
⁢
⁢
2
⁢
y
)
]
(
6
)
where an amplitude term is A(x, y) and a phase term is P(x, y) in the unit constituent region R(x, y), the complex amplitude F(x, y) is defined by following Formula (7), and
F(x,y)=A(x,y)×exp{jP(x,y)} (7)
when the unit constituent region R(x, y) is defined by an s-axis and a t-axis that are parallel to the X-axis and the Y-axis, respectively, and are orthogonal at the lattice point O(x, y),
the phase modulation layer is configured such that
the gravity center G of the corresponding modified refractive index region is positioned on a straight line passing through the lattice point O(x, y) and having a predetermined tilt angle with respect to the s-axis, and the corresponding modified refractive index region, which satisfies a following relationship of a line segment length r(x, y) from the lattice point O(x, y) to the gravity center G of the corresponding modified refractive index region, is arranged in the unit constituent region R(x, y)
r(x,y)=C×(P(x,y)−P0)
C:
proportional constant
P0:
arbitrary constant.

141 more elements

Dependencies are inferred from the claim text.

Facts

Application: 16/769,805Filed 28 Nov 2018
Priority: JP JP2017-2361988 Dec 2017
Published: US 2020/0373739 A126 Nov 2020
Granted: 11 Apr 2023
Term ends: Not estimatedThe source records don’t support an estimate.

Classification18 codes

H01S 5/11
Construction or shape of the optical resonator , e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or…:…
H01S 5/222
Having special optical properties: having a refractive index lower than that of the cladding layers or outer guiding layers
H01S 5/04254
Electrodes, e.g. characterised by the structure: characterised by the shape
H01S 5/0427
Electrical excitation ; Circuits therefor: for applying modulation to the laser