# US 2016/0258807 A1 · Systems, Methods, and Apparatus for Radiation Detection

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2016/0258807 A1
- Document ID: US20160258807A1
- Status: Published application
- Kind: A1
- Application number: 15/061,308
- Filed: 2016-03-04
- Published: 2016-09-08
- Earliest claimed: 2015-03-06
- Assignees: Massachusetts Institute of Technology
- Inventors: Brandt Christopher Pein; Harold Young Hwang; Wendi Chang; Keith A. Nelson; Vladimir Bulovic; Nathaniel C. Brandt
- Web page: https://patentgrep.com/patent/US20160258807A1

## CPC

- G01J 5/046: {Materials; Selection of thermal materials}
- G01J 1/58: using luminescence generated by light
- G01J 3/0216: {using light concentrators or collectors or condensers}
- G01J 3/0245: {using an optical amplifier of light, e.g. doped fiber}
- G01J 3/04: Slit arrangements {slit adjustment}
- G01J 3/42: Absorption spectrometry; Double beam spectrometry; Flicker spectrometry; Reflection spectrometry (beam switching arrangements G01J3/08)
- G01J 5/0815: {Light concentrators, collectors or condensers}
- G01J 5/0837: {Microantennas, e.g. bow-tie}
- G01J: MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY (light sources F21, H01J, H01K, H05B; investigating properties of materials by optical means G01N)

## Abstract

A radiation detection technique employs field enhancing structures and electroluminescent materials to converts incident Terahertz (THz) radiation into visible light and/or infrared light. In this technique, the field-enhancing structures, such as split ring resonators or micro-slits, enhances the electric field of incoming THz light within a local area, where the electroluminescent material is applied. The enhanced electric field then induces the electroluminescent material to emit visible and/or infrared light via electroluminescent process. A detector such as avalanche photodiode can detect and measure the emitted light. This technique allows cost-effective detection of THz radiation at room temperatures.

## Claims

### Claim 1

An apparatus for detecting electromagnetic radiation including at least one spectral component having a frequency within a range of about 100 GHz to about 100 THz, the apparatus comprising:
at least one conductive structure defining at least one gap to receive the electromagnetic radiation and generate an enhanced electric field in response to the at least one spectral component; and
an electroluminescent (EL) material disposed at least partially within the at least one gap to emit light in response to the enhanced electric field.

### Claim 2 (depends on 1)

The apparatus of claim 1, wherein the at least one conductive structure comprises at least one split ring resonator.

### Claim 3 (depends on 2)

The apparatus of claim 2, wherein the at least one split ring resonator comprises a first split ring resonator having a first resonant frequency and a second split ring resonator having a second resonant frequency different than the first resonant frequency.

### Claim 4 (depends on 3)

The apparatus of claim 3, wherein the first resonant frequency and the second resonant frequency are with the range of about 100 GHz to about 100 THz.

### Claim 5 (depends on 1)

The apparatus of claim 1, wherein the at least one conductive structure comprises at least two conductive strips and the at least one gap comprises at least one micro-slit defined by the at least two conductive strips, the at least one micro-slit having a width of about 0.1 μm to about 10 μm.

### Claim 6 (depends on 5)

The apparatus of claim 5, wherein a first conductive strip in the at least two conductive strips is electrically coupled to a first electrode and a second conductive strip in the at least two conductive strips is electrically coupled to a second electrode to generate a direct current (DC) electric field across the at least one micro-slit.

### Claim 7 (depends on 5)

The apparatus of claim 5, wherein the at least one micro-slit comprises a plurality of micro-slits defined by a plurality of interdigitated conductive strips.

### Claim 8 (depends on 7)

The apparatus of claim 7, wherein a first plurality of conductive strips in the plurality of interdigitated conductive strips is electrically coupled to a first electrode and a second plurality of conductive strips in the plurality of interdigitated conductive strips is electrically coupled to a second electrode so as to generate a direct current (DC) electric field in the plurality of micro-slits.

### Claim 9 (depends on 1)

The apparatus of claim 1, wherein the EL material is configured to emit visible light.

### Claim 10 (depends on 1)

The apparatus of claim 1, wherein the EL material is configured to emit infrared light.

### Claim 11 (depends on 1)

The apparatus of claim 1, wherein the EL material comprises Alq3.

### Claim 12 (depends on 1)

The apparatus of claim 1, wherein the EL material comprises Alq3 doped with 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran.

### Claim 13 (depends on 1)

The apparatus of claim 1, wherein the EL material comprises at least one quantum dot.

### Claim 14 (depends on 1)

The apparatus of claim 1, further comprising:
a detector, in optical communication with the EL material, to detect the light emitted by the EL material.

### Claim 15 (depends on 14)

The apparatus of claim 14, wherein the detector comprises at least one of an avalanche photodiode and an intensified charge-coupled-device.

### Claim 16 (depends on 14)

The apparatus of claim 14, wherein the at least one conductive structure is disposed on the detector.

### Claim 17 (depends on 14)

The apparatus of claim 14, further comprising:
a relay optic, in optical communication with the EL material and the detector, to transmit the light emitted by the EL material onto the detector.

### Claim 18 (depends on 1)

The apparatus of claim 1, further comprising:
a silicon oxide layer, disposed between the at least one conductive structure and the EL material, to electrically insulate the at least one conductive structure from the EL material.

### Claim 19 (depends on 1)

The apparatus of claim 1, further comprising:
a light source, in optical communication with the EL material, to illuminate the EL material with a beam of light having a photon energy below a band gap of the EL material so as to increase a sensitivity of the apparatus to the at least one spectral component.

### Claim 20

A method of detecting electromagnetic radiation including at least one spectral component having a frequency within a range of about 100 GHz to about 100 THz, the method comprising:
receiving the electromagnetic radiation at a field-enhancing structure (FES);
generating an enhanced electric field at the FES in response to the at least one spectral component;
emitting light from an electroluminescent (EL) material electromagnetically coupled to the FES in response to the enhanced electric field; and
detecting the light emitted by the EL material.

### Claim 21 (depends on 20)

The method of claim 20, wherein receiving the electromagnetic radiation at the FES comprises receiving the electromagnetic radiation at a micro-slit defined by at least two conductive strips.

### Claim 22 (depends on 21)

The method of claim 21, further comprising
applying a direct current (DC) electric field across the micro-slit to increase a sensitivity of the apparatus.

### Claim 23 (depends on 20)

The method of claim 20, wherein receiving the electromagnetic radiation at the FES comprises receiving the electromagnetic radiation at a split ring resonator.

### Claim 24 (depends on 20)

The method of claim 20, wherein emitting the light from the EL material comprises emitting visible light.

### Claim 25 (depends on 20)

The method of claim 20, wherein emitting the light from the EL material comprises emitting infrared light.

### Claim 26 (depends on 20)

The method of claim 20, further comprising:
illuminating the EL material with a light beam having a photon energy below a band gap of the material so as to increase a sensitivity of the apparatus.

### Claim 27 (depends on 20)

The no method of claim 20, wherein the FES is deposited on a detector and wherein detecting the light comprises detecting the light with the detector.

### Claim 28 (depends on 20)

The method of claim 20, wherein detecting the light comprises:
transmitting the light through a lens; and
detecting the light transmitted through the tens using a detector.

### Claim 29

An apparatus for detecting Terahertz radiation, the apparatus comprising:
a substrate;
a field-enhancing structure (FES), disposed on the substrate, to receive the Terahertz radiation, the FES comprising an array of interdigitated conductive strips defining a plurality of micro-slits to generate an enhanced electric field in response to the Terahertz radiation, the array of interdigitated conductive strips having a pitch of about 10 μm to about 100 μm and each micro-slit in the plurality of micro-slits having a width of about 0.1 μm to about 10 μm;
a first electrode electrically coupled to a first plurality of metal strips in the plurality of interdigitated metal strips;
a second electrode electrically coupled to a second plurality of metal strips in the plurality of interdigitated metal strips to apply a direct current (DC) electric field across the plurality of micro-slits;
an electroluminescent (EL) material, disposed at least partially within the plurality of micro-slits, to generate light at a wavelength of about 450 nm to about 700 nm in response to the enhanced electric field; and
a detector, in optical communication with the EL material, to detect the light generated by the EL material.