# US 7,610,071 B2 · Tunable, superconducting, surface-emitting teraherz source

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- Number: US 7,610,071 B2
- Document ID: US7610071B2
- Status: Granted
- Kind: B2
- Application number: 11/728,615
- Filed: 2007-03-27
- Published: 2007-10-18
- Granted: 2009-10-27
- Earliest claimed: 2006-03-27
- Assignees: Uchicago Argonne, LLC
- Inventors: Ulrich Welp; Alexei E. Koshelev; Kenneth E. Gray; Wai-Kwong Kwok; Vitalii Vlasko-Vlasov
- Web page: https://patentgrep.com/patent/US7610071B2

## CPC

- H10N 60/124: {comprising high-Tc ceramic materials}
- H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR

## Abstract

A compact, solid-state THz source based on the driven Josephson vortex lattice in a highly anisotropic superconductor such as Bi2Sr2CaCu2O8 that allows cw emission at tunable frequency. A second order metallic Bragg grating is used to achieve impedance matching and to induce surface emission of THz-radiation from a Bi2Sr2CaCu2O8 sample. Steering of the emitted THz beam is accomplished by tuning the Josephson vortex spacing around the grating period using a superimposed magnetic control field.

## Claims

### Claim 1

A tunable terahertz device, comprising:
a first superconducting stack having a top surface;
a first metallic layer which is disposed on the top surface of the superconducting stack and the first metallic layer comprises a patterned grating; and
a second metallic conducting layer coupled electrically to a bottom of the superconducting stack.

### Claim 2 (depends on 1)

The tunable terahertz device as defined in claim 1 wherein the second metallic conducting layer is disposed at a location selected from the group of disposed on the bottom of the first superconducting stack and adjacent the first superconducting stack.

### Claim 3 (depends on 2)

The tunable terahertz device as defined in claim 2 further including a substrate superconductor stack disposed below at least one of the second metallic conducting layer and below the first superconducting stack.

### Claim 4 (depends on 1)

The tunable terahertz device as defined in claim 1 further including a source of magnetic field for application to the tunable terahertz device.

### Claim 5 (depends on 1)

The tunable terahertz device as defined in claim 1 wherein the first superconducting stack is composed of superconducting layers that are Josephson-coupled across intervening insulating layers.

### Claim 6 (depends on 1)

The tunable terahertz device as defined in claim 1 wherein the first superconducting stack is comprised of a high-temperature superconductor Bi2Sr2CaCu2O8.

### Claim 7 (depends on 1)

The tunable terahertz device as defined in claim 1 wherein the metal grating comprises a plurality of slots in the metal grating layer.

### Claim 8 (depends on 1)

The tunable terahertz device as defined in claim 1 wherein the first superconducting stack comprises between about 70-100 separate layers of superconductor.