HYBRID VERTICAL CAVITY LASER FOR PHOTONIC INTEGRATED CIRCUIT

• US 20140098833A1
• Filed: 08/23/2013
• Published: 04/10/2014
• Est. Priority Date: 10/10/2012
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: KIM, Taek, SHCHERBATKO, Igor
• Granted Patent: US 9,054,489 B2
• Time in Patent Office: Days
• US Class Current: 372/44.011
• CPC Class Codes: H01S 5/021 Silicon based substrates
• CPC Class Codes: H01S 5/0215 Bonding to the substrate
• 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 5/10 Construction or shape of the optical resonator , e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region H01S5/20 takes precedence
• 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 5/11 Comprising a photonic bandgap structure
• CPC Class Codes: H01S 5/1206 having a non constant or multiplicity of periods
• CPC Class Codes: H01S 5/1218 in superstructured configuration, e.g. more than one period in an alternate sequence
• CPC Class Codes: H01S 5/18308 having a special structure for lateral current or light confinement
• CPC Class Codes: H01S 5/18341 Intra-cavity contacts
• CPC Class Codes: H01S 5/18361 Structure of the reflectors, e.g. hybrid mirrors
• CPC Class Codes: H01S 5/18363 comprising air layers
• CPC Class Codes: H01S 5/1838 Reflector bonded by wafer fusion or by an intermediate compound
• CPC Class Codes: H01S 5/2018 Optical confinement, e.g. absorbing-, reflecting- or waveguide-layers
• CPC Class Codes: H01S 5/2063 obtained by particle bombardment

Abstract

According to example embodiments, a hybrid vertical cavity laser for a photonic integrated circuit (PIC) includes: a grating mirror between first and second low refractive index layers, an optical waveguide optically coupled to one side of the grating mirror, a III-V semiconductor layer including an active layer on an upper one of the first and second low refractive index layers, and a top mirror on the III-V semiconductor layer. The grating mirror includes a plurality of bar-shaped low refractive index material portions arranged parallel to each other. The low refractive index material portions include a plurality of first portions having a first width and a plurality of second portions having second width in a width direction. The first and second widths are different.

Claims

1. A hybrid vertical cavity laser for a photonic integrated circuit (PIC), the laser comprising:

a first low refractive index layer;

a second low refractive index layer on the first low refractive index layer;

a grating mirror between the first and second low refractive index layers,

the grating mirror including a material layer,

the first and second low refractive index layers each having refractive indices that are lower than a refractive index of the material layer,

the grating mirror including a plurality of low refractive index material portions in the material layer,

the plurality of low refractive index material portions being arranged parallel to each other and each having a bar shape,

the plurality of low refractive index material portions extending in a first direction,

the plurality of low refractive index material portions each having a lower refractive index than the refractive index of the material layer,

the plurality of low refractive index material portions including a plurality of first portions having a first width in a second direction and a plurality of second portions having a second width in the second direction,

the second width being different than the first width;

an optical waveguide optically coupled to one side of the grating mirror in the second direction,

the second direction being perpendicular to the first direction;

a Group III-V semiconductor layer on the second low refractive index layer,

the Group III-V semiconductor layer including an active layer; and

a top mirror on the Group III-V semiconductor layer.

2. The laser of claim 1, wherein the material layer is a silicon layer.

3. The laser of claim 1, wherein a material of the plurality of low refractive index material portions is air.

4. The laser of claim 1, wherein the second width is 10 nm to 50 nm greater than the first width.

5. The laser of claim 4, wherein the plurality of first portions are alternately arranged with the plurality of second portions.

6. The laser of claim 4, wherein each one of the plurality of second portions is alternately arranged with at least two of the plurality of first portions.

7. The laser of claim 4, wherein

N is greater than or equal to 3,

less than N of the plurality of second portions are alternately arranged with every N of the plurality of first portions.

8. The laser of claim 4, wherein the first width is about 100 nm to about 200 nm.

9. The laser of claim 1, wherein the material layer of the grating mirror and the optical waveguide are defined by a top silicon layer of a silicon-on-oxide (SOI) substrate.

10. The laser of claim 1, wherein

the material layer is a silicon layer, and

the silicon layer includes portions having a constant width between the plurality of low refractive index material portions.

11. The laser of claim 1, further comprising:

a third low refractive index layer having lower refractive index than silicon between the grating mirror and the second low refractive index layer, wherein

a pattern of the third low refractive index layer corresponds to a pattern of the material layer of the grating mirror, and

the plurality of low refractive index material portions are surrounded by the material layer, the first low refractive index layer, the second low refractive index layer, and the third low refractive index layer.

12. A hybrid vertical cavity laser for a photonic integrated circuit (PIC), the laser comprising:

a first low refractive index layer;

a second low refractive index layer on the first low refractive index layer;

a grating mirror between the first and second low refractive index layers,

the grating mirror including a plurality of bars that are spaced apart from each other and arranged in a two-dimensional array,

the first and second low refractive index layers each having refractive indices that are lower than a refractive index of the plurality of bars;

an optical waveguide optically coupled to one side of the grating mirror in a first direction;

a Group III-V semiconductor layer on the second low refractive index layer,

the Group III-V semiconductor layer including an active layer; and

a top mirror on the Group III-V semiconductor layer.

13. The laser of claim 12, wherein

each of the plurality of bars are elongated in a second direction that crosses the first direction, and

the plurality of bars are a plurality of silicon bars.

14. The laser of claim 13, wherein the plurality of bars and the optical waveguide are defined by a top silicon layer of a silicon-on-oxide (SOI) substrate.

15. The laser of claim 12, further comprising

a third low refractive index layer having lower refractive index than silicon between the plurality of bars of the grating mirror and the second low refractive index layer, wherein a pattern of the third insulator layer corresponds to a pattern of the plurality of bars.

16. A hybrid vertical cavity laser for a photonic integrated circuit (PIC), the laser comprising:

a first low refractive index layer;

a second low refractive index layer on the first low refractive index layer;

a grating mirror between the first and second low refractive index layers,

the grating mirror including a material layer,

the first and second low refractive index layers having refractive indices that are lower than a refractive index of the material layer,

the grating mirror including a plurality of low refractive index portions that are separated by parts of the material layer,

the plurality of low refractive index material portions being arranged parallel to each other and each having a bar shape,

each one of the plurality of low refractive index material portions, in combination with an adjacent one of the parts of the material layer, having a same pitch in a first direction,

the plurality of low refractive index material portions extending in a second direction that is perpendicular to the first direction,

the plurality of low refractive index material portions having a refractive index that is lower than the refractive index of the material layer, and

the plurality of low refractive index material portions including a plurality of first portions having a first width in the first direction and a plurality of second portions having a second width that is different than the first width and extends in the first direction;

an optical waveguide optically coupled to one side of the grating mirror in a first direction;

a Group III-V semiconductor layer on the second low refractive index layer,

the Group III-V semiconductor layer including an active layer; and

a top mirror on the Group III-V semiconductor layer.

17. The laser of claim 16, wherein the material layer is a silicon layer.

18. The laser of claim 16, wherein a material of each of the plurality of low refractive index material portions is air.

19. The laser of claim 16, wherein the second width is 10 nm to 50 nm greater than the first width.

20. The laser of claim 19, wherein the plurality of first portions are alternately arranged with the plurality of second portions.

21. The laser of claim 19, wherein each one of the plurality of second portions is alternately arranged with at least two of the plurality of first portions.

22. The laser of claim 19, wherein

N is greater than or equal to 3,

less than N of plurality of second portions are alternately arranged with every N of the plurality of first portions.

23. The laser of claim 19, wherein the first width is about 100 nm to about 200 nm.

24. The laser of claim 16, wherein the material layer and the optical waveguide are defined by a top silicon layer of a silicon-on-oxide (SOT) substrate.

25. The laser of claim 16, further comprising:

a third low refractive index layer having lower refractive index than silicon which is between the grating mirror and the second low refractive index layer, wherein

a shape of the third low refractive index layer corresponds to a shape of the material layer of the grating mirror, and the plurality of low refractive index material portions have a bar shape, and

the plurality of low refractive index material portions are surrounded by the material layer, the third low refractive index layer, and the first and second low refractive index layers.