Wireless light dosimeter

Patent metadata

Field	Value
Publication number	US-12270702-B2
Application number	US-202118247675-A
Country	US
Kind code	B2
Filing date	Oct 4, 2021
Priority date	Oct 5, 2020
Publication date	Apr 8, 2025
Grant date	Apr 8, 2025

Abstract

A light sensing device includes: a light sensitive layer having a phosphor with two different types of lanthanides dopant ions, switching between a first state and a second state; one or more optical filters on top of the light sensitive layer. When the dopant ions are in the second state after exposure of the light sensitive layer to the second light energy, the light sensitive layer measures a first light intensity of light of the first light energy. When the dopant ions are in the first state after exposure of the light sensitive layer to the first light energy, the light sensitive layer measures a second light intensity of light of the second light energy.

First claim

The invention claimed is:

1. A light sensing device for measuring a light intensity, comprising:
a light sensitive layer comprising a phosphor into which two different types of dopant ions are incorporated,
wherein one of said types of dopant ions is a first lanthanide and wherein the other one of said types of dopant ions is a second lanthanide different from said first lanthanide;
wherein said dopant ions are in a first state and/or in a second state and wherein:
a charge transfer of said dopant ions from said first state to said second state happens when said light sensitive layer is exposed to a second light energy, and
wherein said charge transfer of said dopant ions from said first state to said second state corresponds to a reverse charge transfer between said first lanthanide and said second lanthanide; and
a charge transfer of said dopant ions from said second state to said first state happens when said light sensitive layer is exposed to a first light energy larger than said second light energy,
wherein said first light energy corresponds to a wavelength comprised between 200 nm and 600 nm; and
wherein said charge transfer of said dopant ions from said second state to said first state corresponds to a forward charge transfer between said first lanthanide and said second lanthanide;
one or more optical filters on top of said light sensitive layer and being used to tune a spectral response of said light sensing device;
wherein said optical filters comprise a neutral density filter configured to allow tuning a dynamic range of said light sensing device; and wherein:
when said dopant ions are in said second state after exposure of said light sensitive layer to said second light energy, said light sensitive layer is configured to measure a first light intensity,
wherein said first light intensity is an intensity of light of said first light energy inducing said forward charge transfer between said first lanthanide and said second lanthanide bringing an amount of dopant ions from said second state to said first state; and
when said dopant ions are in said first state after exposure of said light sensitive layer to said first light energy, said light sensitive layer is configured to measure a second light intensity,
wherein said second light intensity is an intensity of light of said second light energy inducing said reverse charge transfer between said first lanthanide and said second lanthanide bringing an amount of dopant ions from said first state to said second state.

2. The light sensing device according to claim 1 , wherein said first light energy corresponds to a first wavelength which is shorter than the emission wavelength of said phosphor.

3. The light sensing device according to claim 1 , wherein said second light energy corresponds to a second wavelength which is longer than the emission wavelength of said phosphor.

4. The light sensing device according to claim 1 , wherein said light sensing device further comprises a casing positioned between said light sensitive layer and said one or more optical filters when said light sensitive layer measures said first light intensity or when said light sensitive layer measures said second light intensity.

5. The light sensing device according to claim 1 , wherein said one or more optical filters comprise one or more of the following:
a color filter configured to allow selecting a wavelength range over which said light sensing device operates.

6. A read-out device for determining a light intensity measured by a light sensing device according to claim 1 , wherein said read-out device comprises:
a stimulation light source configured to emit light of said second light energy and to expose said light sensitive layer to said second light energy, thereby allowing a charge transfer of said dopant ions from said first state to said second state; and
an excitation light source configured to emit light of said first light energy and to expose said light sensitive layer to said first light energy, thereby allowing a charge transfer of said dopant ions from said second state to said first state.

7. The read-out device according to claim 6 , wherein said read-out device further comprises:
a read-out optical filter positioned between said light sensitive layer and said sensor; and
wherein said sensor is configured to determine a read-out light intensity emitted by said light sensitive layer when said light sensitive layer is exposed to said second light energy of said stimulation light source; and
wherein said read-out optical filter is configured to discriminate between said read-out light intensity and said second light energy of said stimulation light source when said light sensitive layer is exposed to said second light energy.

8. The read-out device according to claim 7 , wherein said read-out light intensity is an optically stimulated luminescence of said light sensitive layer; and wherein:
said optically stimulated luminescence corresponds to a first light intensity of light of said first light energy measured by said light sensitive layer; or
a second light intensity of light of said second light energy measured by said light sensitive layer can be determined from said optical stimulated luminescence.

9. A wireless light dosimeter comprising one or more light sensing devices, and a read-out device according to claim 6 .

10. A method for determining a light intensity, comprising:
providing a light sensitive layer comprising a phosphor into which two different types of dopant ions are incorporated, wherein one of said types of dopant ions is a first lanthanide and
wherein the other one of said types of dopant ions is a second lanthanide different from said first lanthanide;
wherein said dopant ions are in a first state and/or in a second state and wherein:
a charge transfer of said dopant ions from said first state to said second state happens when said light sensitive layer is exposed to a second light energy, and
wherein said charge transfer of said dopant ions from said first state to said second state corresponds to a reverse charge transfer between said first lanthanide and said second lanthanide; and
a charge transfer of said dopant ions from said second state to said first state happens when said light sensitive layer is exposed to a first light energy larger than said second light energy,
wherein said first light energy corresponds to a wavelength comprised between 200 nm and 600 nm; and
wherein said charge transfer of said dopant ions from said second state to said first state corresponds to a forward charge transfer between said first lanthanide and said second lanthanide;
providing one or more optical filters on top of said light sensitive layer and being used to tune a spectral response of said light sensing device;
wherein said optical filters comprise a neutral density filter configured to allow tuning a dynamic range of said light sensing device; and
wherein said method further comprises:
exposing said light sensitive layer to said second light energy, thereby bringing said dopant ions in said second state; and
measuring with said light sensitive layer a first light intensity,
wherein said first light intensity is an intensity of light of said first light energy inducing said forward charge transfer between said first lanthanide and said second lanthanide bringing an amount of dopant ions from said second state to said first state; or:
exposing said light sensitive layer to said first light energy, thereby bringing said dopant ions in said first state; and
measuring with said light sensitive layer a second light intensity,
wherein said second light intensity is an intensity of light of said second light ener

Assignees

• Univ Gent

Inventors

• Smet Philippe
• Van Der Heggen David

Classifications

• G01J1/58 Primary

  using luminescence generated by light · CPC title

• G01J1/08

  Arrangements of light sources specially adapted for photometry {standard sources, also using luminescent or radioactive material} · CPC title

• G01T1/10

  Luminescent dosimeters · CPC title

• G01J1/0418 Primary

  using attenuators · CPC title