Plasmonic laser

Patent metadata

Field	Value
Publication number	US-11056856-B2
Application number	US-201916274277-A
Country	US
Kind code	B2
Filing date	Feb 13, 2019
Priority date	Feb 13, 2019
Publication date	Jul 6, 2021
Grant date	Jul 6, 2021

Abstract

Embodiments of the invention relate to a plasmonic laser including a substrate and a coaxial plasmonic cavity formed on the substrate and adapted to facilitate a plasmonic mode. The plasmonic laser further includes an electrical pumping circuit configured to electrically pump the plasmonic laser. The coaxial plasmonic cavity includes a peripheral plasmonic ring structure, a central plasmonic core and a gain structure arranged between the peripheral plasmonic ring structure and the central plasmonic core. The gain structure includes one or more ring-shaped quantum wells as gain material. The one or more ring-shaped quantum wells have a surface that is aligned orthogonal to a surface of the substrate. The electrical pumping circuit is configured to pump the plasmonic laser via the peripheral plasmonic ring structure and the central plasmonic core.

First claim

What is claimed is:

1. A plasmonic laser comprising:
a substrate;
a coaxial plasmonic cavity formed on the substrate and adapted to facilitate a plasmonic mode; and
an electrical pumping circuit configured to electrically pump the plasmonic laser;
wherein the coaxial plasmonic cavity comprises:
a peripheral plasmonic ring structure;
a central plasmonic core; and
a gain structure being arranged between the peripheral plasmonic ring structure and the central plasmonic core, the gain structure comprising a plurality radial quantum wells arranged concentrically as gain material in which the radial quantum wells are radially separated from one another by an intervening layer, the radial quantum wells having a surface that is aligned orthogonal to a surface of the substrate; and

wherein the electrical pumping circuit is configured to pump the plasmonic laser via the peripheral plasmonic ring structure and the central plasmonic core.

2. A plasmonic laser as claimed in claim 1 , wherein the gain structure comprises a doping profile adapted to form a pin-structure.

3. A plasmonic laser as claimed in claim 1 , wherein the peripheral plasmonic ring structure and the central plasmonic core are configured to facilitate the excitation and sustention of surface plasmons.

4. A plasmonic laser as claimed in claim 1 , wherein the peripheral plasmonic ring structure and the central plasmonic core comprise a material selected from a group consisting of a metal and a doped semiconductor material.

5. A plasmonic laser as claimed in claim 1 , wherein:
the quantum wells are formed by quantum well layers of a second group III-V semiconductor material;
the quantum well layers are embedded within cladding layers of a first group III-V semiconductor material to form the intervening layer; and
the first group III-V semiconductor material has a different band gap than the second group III-V semiconductor material.

6. A plasmonic laser as claimed in claim 5 , wherein:
the first and the second group III-V semiconductor materials are selected from the pairs consisting of InP and InGaAs; AlGaAs and GaAs; GaAs; and InGaAs.

7. A plasmonic laser as claimed in claim 1 , wherein the gain structure comprises:
a positively doped semiconductor layer of a first semiconductor material; and
a negatively doped semiconductor layer of the first semiconductor material;

wherein the quantum wells are arranged between the positively doped semiconductor layer and the negatively doped semiconductor layer; and
wherein the quantum wells comprise a second semiconductor material different from the first semiconductor material.

8. A plasmonic laser as claimed in claim 1 , wherein the plasmonic laser is configured to generate a hybrid plasmonic-photonic mode.

9. A plasmonic laser as claimed in claim 8 , wherein the plasmonic laser comprises an oxide layer between the peripheral plasmonic ring structure and the gain structure.

10. A plasmonic laser as claimed in claim 1 , wherein the plasmonic laser is configured to generate whispering gallery modes.

11. A plasmonic laser as claimed in claim 1 , wherein a shape of the quantum wells comprises a hexagonal shape.

12. A plasmonic laser as claimed in claim 1 , wherein the central plasmonic core comprises a metal plug.

13. A plasmonic laser as claimed in claim 1 , wherein:
the plasmonic cavity comprises a diameter between about 100 nm and about 2 μm; and
the quantum wells comprise a width between about 5 nm and about 20 nm.

14. A method for fabricating a plasmonic laser, the method comprising:
providing a semiconductor substrate;
forming an insulating layer on the semiconductor substrate;
forming an opening in the insulating layer, thereby exposing a seed surface of the semiconductor substrate;
forming a template structure above the insulating layer, the template structure encompassing a template cavity comprising the opening;
epitaxially growing from the seed surface a gain structure in the template cavity, the gain structure comprising a plurality of ring-shaped quantum wells arranged concentrically in which the ring-shaped quantum wells are radially separated from one another by an intervening layer;
selectively removing the template structure;
forming a central hole in the gain structure;
forming a central plasmonic core in the central hole; and
forming a peripheral plasmonic ring structure all around a vertical edge of the gain structure.

15. A method as claimed in claim 14 , wherein growing the gain structure comprises growing the ring-shaped quantum wells in the template cavity.

16. A method as claimed in claim 14 , wherein growing the gain structure comprises:
growing in the template cavity a first doped semiconductor layer of a first semiconductor material;
growing in the template cavity a quantum well layer of a second semiconductor material on the first doped semiconductor layer; and
growing in the template cavity a second doped semiconductor layer of the first semiconductor material.

17. The method as claimed in claim 14 further comprising growing a plurality of quantum well layers by growing sequentially in the template cavity in an alternating way a plurality of semiconductor layers of a first semiconductor material and a plurality of quantum well layers of a second semiconductor material, the first semiconductor material being different from the second semiconductor material.

18. The method as claimed in claim 14 , wherein the growing of the gain structure is performed by one of a metal organic chemical vapor deposition (MOCVD); atmospheric pressure CVD; low or reduced pressure CVD; ultra-high vacuum CVD; molecular beam epitaxy (MBE); atomic layer deposition (ALD); and hydride vapor phase epitaxy.

19. A method as claimed in claim 14 , further comprising:
forming an electrical pumping circuit;
providing an electrical connection between the electrical pumping circuit and the peripheral plasmonic ring structure; and
providing an electrical connection between the electrical pumping circuit and the central plasmonic core.

20. The method as claimed in claim 15 , wherein the width of the quantum wells in a lateral growth direction is controlled via one or more growth parameters of the epitaxial growth, the one or more growth parameters including a duration of the epitaxial growth.

Assignees

• IBM

Inventors

• Mauthe Svenja
• Moselund Kirsten Emilie

Classifications

• H01S5/1046 Primary

  Comprising interactions between photons and plasmons, e.g. by a corrugated surface · CPC title

• H01S5/04257

  having positive and negative electrodes on the same side of the substrate · CPC title

• H01S5/3059

  in II-VI materials · CPC title

• H01S5/021

  Silicon based substrates · CPC title

• H01S3/0632

  Thin film lasers in which light propagates in the plane of the thin film · CPC title