SEMICONDUCTOR LIGHT-EMITTING MODULE AND CONTROL METHOD THEREFOR

• US 20190312410A1
• Filed: 06/05/2019
• Published: 10/10/2019
• Est. Priority Date: 03/27/2017
• Status: Active Grant

• Current Assignee: Hamamatsu Photonics KK
• Original Assignee: Hamamatsu Photonics KK
• Inventors: SUGIYAMA, Takahiro, TAKIGUCHI, Yuu, KUROSAKA, Yoshitaka, HIROSE, Kazuyoshi, NOMOTO, Yoshiro, UENOYAMA, Soh
• Granted Patent: US 11,637,409 B2
• Time in Patent Office: Days
• CPC Class Codes: H01S 2301/02 ASE (amplified spontaneous emission), noise; Reduction thereof
• CPC Class Codes: H01S 2301/18 Semiconductor lasers with special structural design for influencing the near- or far-field
• CPC Class Codes: H01S 5/02325 Mechanically integrated components on mount members or optical micro-benches
• CPC Class Codes: H01S 5/0287 Facet reflectivity
• CPC Class Codes: H01S 5/04254 characterised by the shape
• CPC Class Codes: H01S 5/04256 characterised by the configuration
• CPC Class Codes: H01S 5/0624 controlling the near- or far field
• CPC Class Codes: H01S 5/06243 controlling the position or direction of the emitted beam
• CPC Class Codes: H01S 5/11 Comprising a photonic bandgap structure
• CPC Class Codes: H01S 5/18 Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities
• CPC Class Codes: H01S 5/185 having only horizontal cavities, e.g. horizontal cavity surface-emitting lasers [HCSEL] comprising a photonic bandgap structure H01S5/11
• CPC Class Codes: H01S 5/2027 Reflecting region or layer, parallel to the active layer, e.g. to modify propagation of the mode in the laser or to influence transverse modes
• CPC Class Codes: H01S 5/34313 with a well layer having only As as V-compound, e.g. AlGaAs, InGaAs
• CPC Class Codes: H01S 5/34326 with a well layer based on InGa(Al)P, e.g. red laser
• CPC Class Codes: H01S 5/34333 with a well layer based on Ga(In)N or Ga(In)P, e.g. blue laser
• CPC Class Codes: H01S 5/4087 emitting more than one wavelength
• CPC Class Codes: H01S 5/42 Arrays of surface emitting lasers

Abstract

A semiconductor light-emitting module according to the present embodiment includes a plurality of semiconductor light-emitting elements each outputting light of a desired beam projection pattern; and a support substrate holding the plurality of semiconductor light-emitting elements. Each of the plurality of semiconductor light-emitting elements includes a phase modulation layer configured to form a target beam projection pattern in a target beam projection region. The plurality of semiconductor light-emitting elements include first and second semiconductor light-emitting elements that are different in terms of at least any of a beam projection direction, the target beam projection pattern, and a light emission wavelength.

Claims

1. A semiconductor light-emitting module comprising:

a plurality of semiconductor light-emitting elements each having a first surface from which light is outputted and a second surface opposing the first surface; and

a support substrate having a third surface, a fourth surface opposing the third surface, and a plurality of drive electrodes respectively corresponding to the plurality of semiconductor light-emitting elements, the plurality of drive electrodes arranged on the third surface, the support substrate on which the plurality of semiconductor light-emitting elements are mounted on the third surface in a state where the second surfaces of the plurality of semiconductor light-emitting elements and the third surface face each other with the plurality of drive electrodes interposed therebetween,

wherein each of the plurality of semiconductor light-emitting elements includes;

an active layer positioned between the first surface and the second surface;

a phase modulation layer positioned between the first surface and the second surface and optically coupled to the active layer, the phase modulation layer including a base region having a first refractive index and a plurality of modified refractive index regions each of which is provided in the base region and has a second refractive index different from the first refractive index;

a first cladding layer arranged on a side where the first surface is positioned with respect to a stacked structure including at least the active layer and the phase modulation layer;

a second cladding layer arranged on a side where the second surface is positioned with respect to the stacked structure;

a first-surface-side electrode arranged on a side where the first surface is positioned with respect to the first cladding layer; and

a second-surface-side electrode arranged on a side where the second surface is positioned with respect to the second cladding layer, the second-surface-side electrode connected to a corresponding drive electrode among the plurality of drive electrodes,

each of the plurality of modified refractive index regions is arranged at a predetermined position in the base region according to an arrangement pattern, configured to make a beam projection pattern, which is a projection pattern of light outputted from the first surface when a drive current is supplied from the corresponding drive electrode, and a beam projection region, which is a projection range of the beam projection pattern, coincide with a target beam projection pattern and a target beam projection region, respectively,

in a state that a virtual square lattice constituted by M1 (an integer of one or more)×

N1 (an integer of one or more) unit configuration 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 a normal direction of the first surface and the X-Y plane, which includes X and Y axes orthogonal to each other and coincides with one surface of the phase modulation layer including the plurality of modified refractive index regions,

the arrangement pattern is defined such that a gravity center G1 of the modified refractive index region positioned in a unit configuration region R(x, y) is separated from a lattice point O(x, y) as a center of the unit configuration region R(x, y) by a distance r in the unit configuration region R(x, y) on the X-Y plane, specified by a coordinate component x (an integer of one or more and M1 or less) in an X-axis direction and a coordinate component y (an integer of one or more and N1 or less) in a Y-axis direction, and a vector from the lattice point O(x, y) to the gravity center G1 is directed in a specific direction, and

the plurality of semiconductor light-emitting elements include a first semiconductor light-emitting element and a second semiconductor light-emitting element which are different from each other in terms of at least any of a beam projection direction that defines a traveling direction of light toward the target beam projection region, the target beam projection pattern, and a light emission wavelength.

2. The semiconductor light-emitting module according to claim 1, wherein

a first beam projection direction of the first semiconductor light-emitting element and a second beam projection direction of the second semiconductor light-emitting element are different, and

the first and second beam projection directions are set such that the target beam projection regions of the first and second semiconductor light-emitting elements substantially coincide with each other.

3. The semiconductor light-emitting module according to claim 1, wherein

in such a state that the phase modulation layer satisfies the following first to seventh conditions:

the first condition defined such that a lattice constant of the virtual square lattice is a, the distance r satisfies 0≤

r≤

0.3a;

the second condition defined such that coordinates (x, y, z) in the XYZ orthogonal coordinate system satisfy relationships represented by following Formulas (1) to (3) with respect to spherical coordinates (d1, θ

_tilt, θ

_rot) defined by a length d1 of a radius vector, a tilt angle θ

_tilt from the Z-axis, and a rotation angle θ

_rot from the X-axis specified on the X-Y plane;

x=d1 sin θ

_tilt cos θ

_rot 

 

(1)

y=d1 sin θ

_tilt sin θ

_rot 

 

(2)

z=d1 cos θ

_tilt 

 

(3);

the third condition defined such that a target beam projection pattern is a set of bright spots directed in directions defined by the angles θ

_tilt and θ

_rot, the angles θ

_tilt and θ

_rot are converted to a coordinate value k_x, which is a normalized wave number defined by a following Formula (4), on a Kx-axis corresponding to the X-axis and a coordinate value k_y which is a normalized wave number defined by a following Formula (5), on a Ky-axis corresponds to the Y-axis and orthogonal to the Kx-axis;

4. The semiconductor light-emitting module according to claim 1, wherein

in such a state that the phase modulation layer satisfies the following first to six conditions:

the first condition defined such that coordinates (x, y, z) in the XYZ orthogonal coordinate system satisfy relationships represented by following Formulas (8) to (10) with respect to spherical coordinates (d1, θ

_tilt, θ

_rot) defined by a length d1 of a radius vector, a tilt angle θ

_tilt from the Z-axis, and a rotation angle θ

_rot from the X-axis specified on the X-Y plane;

x=d1 sin θ

_tilt cos θ

_rot 

 

(8)

y=d1 sin θ

_tilt sin θ

_rot 

 

(9)

z=d1 cos θ

_tilt 

 

(10);

the second condition defined such that a target beam projection pattern is a set of bright spots directed in directions defined by the angles θ

_tilt and θ

_rot, the angles θ

_tilt and θ

_rot are converted to a coordinate value k_x, which is a normalized wave number defined by a following Formula (11), on a Kx-axis corresponding to the X-axis and a coordinate value k_y which is a normalized wave number defined by a following Formula (12), on a Ky-axis corresponds to the Y-axis and orthogonal to the Kx-axis;

5. The semiconductor light-emitting module according to claim 1, wherein

at least any of a shape defined on the X-Y plane, an area defined on the X-Y plane, and the distance r defined on the X-Y plane is coincident in all of the plurality of modified refractive index regions in the phase modulation layer in at least one semiconductor light-emitting element among the plurality of semiconductor light-emitting elements including the first and second semiconductor light-emitting elements.

6. The semiconductor light-emitting module according to claim 1, wherein

shapes of the plurality of modified refractive index regions on the X-Y plane are any of a perfect circle, a square, a regular hexagon, a regular octagon, a regular hexadecagon, an equilateral triangle, a right-angled isosceles triangle, a rectangle, an ellipse, a shape in which two circles or ellipses partially overlap each other, an egg shape obtained by deforming an ellipse such that a dimension in a short-axis direction in a vicinity of one end portion along a long axis is smaller than a dimension in the short-axis direction in a vicinity of another end portion, a teardrop shape obtained by deforming one end portion of an ellipse along a long axis into a sharp end portion protruding along a long-axis direction, an isosceles triangle, an arrow shape in which one side of a rectangle forms a triangular notch and a side opposing the one side forms a triangular protrusion, a trapezoid, a pentagon, and a shape in which two rectangles partially overlap each other.

7. The semiconductor light-emitting module according to claim 1, wherein

in at least one semiconductor light-emitting element among the plurality of semiconductor light-emitting elements,

the phase modulation layer includes:

an inner region constituted by M1×

N1 unit configuration regions R; and

an outer region provided so as to surround an outer circumference of the inner region, the outer region including a plurality of peripheral lattice-point-located modified-refractive-index-regions arranged to overlap with lattice points, respectively, in an expanded square lattice defined by setting an identical lattice structure as the virtual square lattice on an outer circumference of the virtual square lattice.

8. The semiconductor light-emitting module according to claim 1, wherein

in at least one semiconductor light-emitting element among the plurality of semiconductor light-emitting elements,

the phase modulation layer includes a plurality of lattice-point-located modified refractive index regions arranged in the M1×

N1 unit configuration regions R, respectively, the plurality of lattice-point-located modified refractive index regions each having a gravity center G2 coinciding with the lattice point O of the corresponding unit configuration region R.

9. A control method for a semiconductor light-emitting module, the method comprising:

preparing the semiconductor light-emitting module according to claim 1;

selecting one or more semiconductor light emitting elements, as objects to be driven, from among the plurality of semiconductor light-emitting elements including the first and second semiconductor light-emitting elements; and

controlling operations of the selected semiconductor light-emitting elements individually by a drive circuit according to a control pattern individually set for each of the selected semiconductor light-emitting elements.

10. The control method for the semiconductor light-emitting module according to claim 9, wherein

the control pattern includes information in which at least a drive timing and a drive time of each of the selected semiconductor light-emitting elements are defined along a time axis.