LASER DEVICE

• US 20140198815A1
• Filed: 07/02/2012
• Published: 07/17/2014
• Est. Priority Date: 07/04/2011
• Status: Active Grant

• Current Assignee: Danmarks Pã¦Dagogiske Universitet
• Original Assignee: Danmarks Pã¦Dagogiske Universitet
• Inventors: Chung, Il-Sug
• Granted Patent: US 8,948,223 B2
• Time in Patent Office: Days
• US Class Current: 372/38.02
• 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 5/0424 lateral current injection
• CPC Class Codes: H01S 5/06226 Modulation at ultra-high frequencies
• 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 5/1228 DFB lasers with a complex coupled grating, e.g. gain or loss coupling
• CPC Class Codes: H01S 5/1234 Actively induced grating, e.g. acoustically or electrically induced
• CPC Class Codes: H01S 5/18311 using selective oxidation
• CPC Class Codes: H01S 5/18319 comprising a periodical structure in lateral directions
• CPC Class Codes: H01S 5/1838 Reflector bonded by wafer fusion or by an intermediate compound
• CPC Class Codes: H01S 5/18386 Details of the emission surface for influencing the near- or far-field, e.g. a grating on the surface
• CPC Class Codes: H01S 5/187 using Bragg reflection

Abstract

The present invention provides a light source for light circuits on a silicon platform. A vertical laser cavity is formed by a gain region arranged between a first mirror structure and a second mirror structure, both acting as mirrors, by forming a grating region including an active material in a silicon layer in a semiconductor structure or wafer structure. A waveguide for receiving light from the region of the mirrors is formed within or to be connected to the region of the mirrors, and functions as an output coupler for the VCL. Thereby, vertical lasing modes are coupled to lateral in-plane modes of the in-plane waveguide formed in the silicon layer, and light can be provided to e.g. photonic circuits on a SOI or CMOS substrate in the silicon.

Claims

1. A laser comprising:

a cavity defined by a first mirroring structure and a second mirroring structure formed in semiconductor layers on a substrate and being arranged to support light oscillation along an oscillation axis normal to a plane of the substrate, wherein;

the first mirroring structure is in the form of a grating formed in a first semiconductor material layer;

an active gain material is provided within the first mirroring structure; and

electric contacts for drawing an electric current through the active gain material to facilitate lasing, wherein the electric contacts for drawing an electric current through the active gain material are positioned in the first mirroring structure on opposite sides of the active gain material as seen in the plane of the layers.

22. The laser according to claim 1, wherein the first semiconductor material layer comprises a III-V semiconductor material.

23. The laser according to claim 1, wherein the first mirroring structure comprises a periodic active grating.

24. The laser according to claim 1, wherein the second mirroring structure comprises a periodic passive grating.

25. The laser according to claim 1, wherein either the first mirroring structure or the second mirroring structure comprises a non-periodic grating and, wherein the first and second mirroring structures are arranged to jointly support a resonance in an optical field.

26. The laser according to claim 1, wherein the second mirroring structure is provided as a distributed Bragg reflector (DBR).

27. The laser according to claim 1, wherein the electric contacts for drawing a current through the active gain material comprises p- and n-doped contact region layers forming part of the first mirroring structure and being positioned vertically above and below the active gain material layer, respectively.

28. The laser according to claim 1, wherein the electric contacts for drawing a current through the active gain material comprises p- and n-doped contact region layers forming part of the first mirroring structure and being positioned laterally on opposite sides of the active gain material.

29. The laser according to claim 1, wherein the second mirroring structure is formed by a periodic or non-periodic refractive index region in a silicon layer, and a waveguide is formed in the silicon layer, wherein the waveguide has an end part formed within or abutting the second mirror structure so as to facilitate coupling of light to the waveguide.

30. The laser according to claim 1, wherein the first and/or second mirroring structures(s) comprises periodically or non-periodically arranged perforations forming a grating region in one or two dimensions.

31. The laser according to claim 30, wherein the perforations are filled with a filling medium so that the refractive index changes periodically or non-periodically in said grating region in directions normal to said oscillation axis.

32. The laser according to claim 31, wherein the active gain material is in a semiconductor material layer and, wherein the gain material is not in contact with the filling medium in the perforations.

33. The laser according to claim 30, wherein the layer including the active gain material is structured so as to avoid regions bordering the perforations.

34. The laser according to claim 30, wherein portions of the active gain material layer border the perforations but are separated from the filling medium by a dielectric material deposited on surfaces in the perforations.

35. The laser according to claim 1, wherein the cavity further comprises a low index region between the first mirroring structure and the second mirroring structure, wherein the low index region comprises a low refractive index material.

36. The laser according to claim 35, wherein the low refractive index material is air.

37. The laser according to claim 35, wherein the low refractive index material has a refractive index of 2 or less.

38. A method of providing a modulated laser light, the method comprising:

providing the laser of claim 1; and

applying a modulated voltage bias between the electric contacts to modulate a laser action of the laser.

39. An optical interconnect for generation of optical data signals based on received electric data signals comprising one or more lasers according to claim 1.

2-21. -21. (canceled)

40. A method for hybridizing a semiconductor laser on a silicon platform, the method comprising:

providing regions of a second mirror structure on a silicon substrate,

wafer-bonding a III-V epi-structure including a first mirror layer and a sacrificial layer onto the patterned silicon substrate,

forming metal contacts and corresponding implantation regions for the contacts,

patterning a first mirror structure in the form of a grating, wherein the first mirror structure comprises an active material; and

removing the sacrificial layer.

41. A method for hybridizing a semiconductor laser on a silicon platform, the method comprising:

providing regions of a second mirror structure on a silicon substrate,

depositing a low refractive-index material onto a III-V epi-structure so as to form a first mirror layer,

wafer-bonding the epi-structure onto the silicon substrate,

forming metal contacts and corresponding implantation regions for the contacts, and

patterning a first mirror structure in the form of a grating, wherein the first mirror structure comprises an active material.