LIGHT EMITTING DEVICE, OPTICAL MODULE AND MANUFACTURING METHOD THEREOF

• US 20180081114A1
• Filed: 04/20/2017
• Published: 03/22/2018
• Est. Priority Date: 09/20/2016
• Status: Active Grant

• Current Assignee: Huazhong University of Science & Technology, Hisense Broadband Multimedia Technologies Co., Ltd (Qingdao Huatong State-Owned Capital Operation (Group) Co., Ltd.)
• Original Assignee: Huazhong University of Science & Technology, Hisense Broadband Multimedia Technologies Co., Ltd (Qingdao Huatong State-Owned Capital Operation (Group) Co., Ltd.)
• Inventors: Li, Xun, Lin, Zekun, Zhang, Hua
• Granted Patent: US 10,324,258 B2
• Time in Patent Office: Days
• CPC Class Codes: G02B 2006/12104 Mirror; Reflectors or the like
• CPC Class Codes: G02B 2006/12121 Laser
• CPC Class Codes: G02B 2006/12147 Coupler
• CPC Class Codes: G02B 6/12002 Three-dimensional structures
• CPC Class Codes: G02B 6/124 Geodesic lenses or integrated gratings
• CPC Class Codes: G02B 6/34 utilising prism or grating G02B6/293 takes precedence
• CPC Class Codes: H01S 2301/173 The laser chip comprising special buffer layers, e.g. dislocation prevention or reduction
• CPC Class Codes: H01S 5/021 Silicon based substrates
• CPC Class Codes: H01S 5/026 Monolithically integrated components, e.g. waveguides, monitoring photo-detectors, drivers stabilisation of output H01S5/06
• CPC Class Codes: H01S 5/0268 Integrated waveguide grating router, e.g. emission of a multi-wavelength laser array is combined by a "dragon router"
• CPC Class Codes: H01S 5/1032 Coupling to elements comprising an optical axis that is not aligned with the optical axis of the active region
• CPC Class Codes: H01S 5/1035 Forward coupled structures [DFC]
• CPC Class Codes: H01S 5/1039 Details on the cavity length
• CPC Class Codes: H01S 5/1215 Multiplicity of periods
• CPC Class Codes: H01S 5/1246 plurality of phase shifts
• 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

Abstract

A light emitting device, an optical module and a manufacturing method thereof are disclosed. According to an example of the disclosure, the light emitting device may comprise an optical waveguide chip, a light emitting chip and a grating between the light emitting chip and the optical waveguide chip. The light emitting chip may emit laser light. The grating may couple the laser light emitted from the active layer into the optical waveguide chip in a way that the laser light is output along a length direction of the optical waveguide chip.

Claims

1. A light emitting device, comprising:

a light emitting chip configured to emit laser light;

an optical waveguide chip configured to output the laser light; and

a grating positioned between the light emitting chip and the optical waveguide chip, wherein the grating is configured to couple the laser light emitted from the light emitting chip into the optical waveguide chip in a way that the laser light is output along a length direction of the optical waveguide chip.

2. The light emitting device of claim 1, wherein

the light emitting chip is configured to emit laser light propagating in a direction orthogonal to the length direction of the light emitting chip;

and

the grating is configured to change propagation direction of laser light in a way that the laser light emitted from the light emitting chip propagates in a direction substantially parallel to the length direction of the optical waveguide chip and injects into the optical waveguide chip.

3. The light emitting device of claim 1, wherein,

the light emitting chip is configured to emit laser light propagating in a direction parallel to the length direction of the light emitting chip;

and

the grating comprises;

a first grating close to the light emitting chip, wherein the first grating is configured to change propagation direction of laser light in a way that the laser light emitted from the light emitting chip propagates in a direction substantially orthogonal to the length direction of the first grating and towards the optical waveguide chip; and

a second grating close to the optical waveguide chip, wherein the second grating is configured to change propagation direction of laser light in a way that the laser light injecting from the first grating towards the optical waveguide chip propagates in a direction substantially parallel to the length direction of the optical waveguide chip and injects into the optical waveguide chip.

4. The light emitting device of claim 3, wherein,

the first grating comprises:

two first first-order gratings configured to select laser light of a preset operating wavelength from the laser light emitted from the light emitting chip and being of at least one wavelength; and

one first second-order grating positioned between the two first first-order gratings, wherein the first second-order grating is configured to twist propagation direction of laser light in a way that the laser light selected by the first first-order gratings propagates in a direction substantially orthogonal to the length direction of the light emitting chip and towards the optical waveguide chip;

the second grating comprises;

one second second-order grating aligning with the first second-order grating, wherein the second second-order grating is configured to twist propagation direction of laser light in a way that the laser light injecting into the second grating propagates in a direction substantially parallel to the length direction of the optical waveguide chip; and

one second first-order grating aligning with one of the first first-order gratings, wherein the second first-order grating is configured to reflect the laser light output from the second second-order grating.

5. The light emitting device of claim 4, wherein,

a phase shift at the connecting portion of the first first-order gratings and the first second-order grating is three-eighths of the operating wavelength;

and

a phase shift at the centre part of the first second-order grating is a quarter of the operating wavelength.

6. The light emitting device of claim 4, wherein,

the second first-order grating is positioned on the left side of the second second-order grating, and

the laser light emitted from the light emitting chip is finally output from the right side of the optical waveguide chip.

7. The light emitting device of claim 4, wherein,

the second first-order grating is positioned on the right side of the second second-order grating, and

the laser light emitted from the light emitting chip is finally output from the left side of the optical waveguide chip.

8. The light emitting device of claim 1, wherein, the optical waveguide chip comprises:

a substrate;

an oxide layer comprising a first buried oxide layer, a reflective layer and a second buried oxide layer which are sequentially laminated on the substrate; and

an optical waveguide layer on one side of the oxide layer away from the substrate, wherein the optical waveguide layer is configured to receive the laser light output from the grating, and the reflective layer is configured to reflect laser light leaking from the optical waveguide layer back.

9. The light emitting device of claim 8, wherein,

the reflective layer comprises n number of silicon dioxide layers and m number of silicon layers alternately laminated on the first buried oxide layer, the n is an integer greater than or equal to 1, the m is an integer greater than or equal to 1;

and

each of the silicon layers and the silicon dioxide layers has a thickness substantially equal to one quarter of an operating wavelength of the light emitting device.

10. The light emitting device of claim 1, wherein, the light emitting chip comprises:

an active layer to emit the laser light; and

a buffer layer on one side of the active layer away from the grating, the buffer layer has a convex part on one side away from the active layer in a way that the convex part aligns with a part of the grating for twisting propagation direction of laser light.

11. An optical module comprising a light emitting device according to claim 1.

12. A method for manufacturing a light emitting device, the method comprising:

forming a second grating on an optical waveguide chip; and

placing a light emitting chip on the optical waveguide chip in a way that the second grating is positioned between the light emitting chip and the optical waveguide chip and capable of coupling laser light emitted from the light emitting chip into the optical waveguide chip and causing the laser light to be output along the length direction of the optical waveguide chip.

13. The method of claim 12, further comprising:

forming a first grating on the light emitting chip, wherein

the light emitting chip is configured to emit laser light propagating in a direction parallel to the length direction of the light emitting chip;

the first grating is configured to change propagation direction of laser light in a way that the laser light emitted from the light emitting chip propagates in a direction substantially orthogonal to the length direction of the first grating and towards the optical waveguide chip; and

the second grating is configured to change propagation direction of laser light in a way that the laser light injecting from the first grating towards the optical waveguide chip propagates in a direction substantially parallel to the length direction of the optical waveguide chip and injects into the optical waveguide chip.

14. The method of claim 13, wherein,

the first grating comprises two first first-order gratings and one first second-order grating positioned between the two first first-order gratings;

and

the second grating comprises one second first-order grating and one second second-order grating, the second first-order grating is aligned with one of the first first-order gratings, and the second second-order grating is aligned with the first second-order grating.

15. A manufacturing method for a light emitting device, the method comprising:

fabricating a III-V group structure on a first substrate, the III-V group structure comprises a buffer layer, an active layer, a first grating and an upper cladding layer laminated in sequence;

fabricating an SOI chip comprising a second substrate, an oxide layer, an optical waveguide layer and a second grating which are laminated in sequence;

welding the III-V group structure to the SOI chip in a way that the first grating and the second grating are positioned between the optical waveguide layer and the active layer;

separating the first substrate from the III-V group structure; and

forming an electrode structure on one side of the buffer layer away from the active layer;

wherein, the active layer is configured to emit laser light propagating in a direction parallel to the length direction of the active layer;

the first grating is configured to change propagation direction of laser light in a way that the laser light emitted from the active layer propagates in a direction substantially orthogonal to the length direction of the first grating and towards the second grating; and

the second grating is configured to change propagation direction of laser light in a way that the laser light injecting into the second grating propagates in a direction substantially parallel to the length direction of the second grating and injects into the optical waveguide layer.

16. The method of claim 15, wherein,

welding the III-V group structure to the SOI chip comprises:

flip-chip bonding the III-V group structure to the SOI chip via a welding layer, and

an orthographic projection area of the welding layer on the first grating does not overlap with an orthographic projection area of the second grating on the first grating.

17. The method of claim 15, wherein, forming the electrode structure on the side of the buffer layer away from the active layer comprising:

forming a convex part by etching the side of the buffer layer away from the active layer;

forming a P-type electrode of the electrode structure on the convex part; and

forming a N-type electrode of the electrode structure on each of concave parts which are on two opposite sides of the convex part respectively.

18. The method of claim 15, wherein,

the first grating comprises two first first-order gratings and one first second-order grating positioned between the two first first-order gratings;

and

the second grating comprises one second first-order grating and one second second-order grating, the second first-order grating is aligned with one of the first first-order gratings, and the second second-order grating is aligned with the first second-order grating.