Optoelectronic ferroelectric sensor and signal generating device

• US 5,663,556 A
• Filed: 06/07/1995
• Issued: 09/02/1997
• Est. Priority Date: 03/02/1995
• Status: Expired due to Fees

• Current Assignee: Northwestern University
• Original Assignee: Northwestern University
• Inventors: Wessels, Bruce W., Block, Bruce A.
• Primary Examiner(s): LE, QUE TAN
• Application Number:
  US08/480,282
• Time in Patent Office: 818 Days
• Field of Search: 250/214 R, 250/214.1, 250/458.1, 250/338.2, 250/227.11, 250/484.1, 250/591, 374/131, 374/161, 374/29, 374/30, 313/503, 313/505, 313/497, 313/49 P
• US Class Current: 250/214.1
• CPC Class Codes: G01K 11/20 using thermoluminescent materials G01K11/32 takes precedence

Abstract

An optoelectronic temperature sensor comprises a doped ferroelectric oxide thin film that exhibits a detectable change in luminescence intensity with temperature as a result of an oxide phase transition when the sensor is heated or cooled through a particular temperature range. The phase of the doped ferroelectric oxide affects the intensity of the luminescence emitted by the doped ferroelectric oxide and thereby provides a temperature dependent parameter or output. The optoelectronic temperature sensor of the present invention can comprise a rare earth or transition metal doped ferroelectric oxide thin film.

Claims

1. Optoelectronic temperature sensor, comprising a doped ferroelectric oxide sensor element that exhibits a detectable change in luminescence intensity with temperature as a result of a phase transition of the doped ferroelectric oxide when the sensor element is heated or cooled through a particular temperature range and means for measuring the change in luminescence intensity.

2. The optoelectronic temperature sensor of claim 1 wherein the ferroelectric oxide sensor element is a thin film doped with a photoluminescent dopant selected from a rare earth metal or transition metal.

3. The optoelectronic temperature sensor of claim 2 wherein the ferroelectric oxide comprises BaTiO₃.

4. The optoelectronic temperature sensor of claim 2 wherein the rare earth metal is Er.

5. Optoelectronic temperature sensor, comprising an Er doped ferroelectric oxide thin film sensor element that exhibits a detectable change in luminescence intensity with temperature as a result of a phase transition of the doped ferroelectric oxide when the sensor element is heated or cooled through a particular temperature range and means for measuring the change in luminescence intensity.

6. Optoelectronic temperature sensitive signal-generating device, comprising a doped ferroelectric oxide temperature sensor element that provides temperature dependent change in luminescence intensity as a result of a phase transition of the doped ferroelectric oxide when the sensor element is heated or cooled through a particular temperature range and a detector for monitoring the change in the intensity of luminescence of said sensor and providing a temperature dependent electrical signal.

7. The optoelectronic temperature sensitive signal-generating device of claim 6 wherein said temperature sensor element comprises a doped ferroelectric oxide thin film that exhibits a detectable change in luminescence intensity with temperature as a result of a phase transition when the sensor is heated or cooled through a particular temperature range.

8. The optoelectronic temperature sensitive signal-generating device of claim 7 wherein the ferroelectric oxide thin film sensor element is doped with a photoluminescent dopant selected from a rare earth metal or transition metal.

9. The optoelectronic temperature sensitive signal-generating device of claim 8 wherein the ferroelectric oxide is doped with Er.

10. The optoelectronic temperature sensitive signal-generating device of claim 6 wherein the detector is a photodetector.

11. The optoelectronic temperature sensitive signal-generating device of claim 6 further including an electrical component actuated in response to said electrical signal of said detector.

12. The optoelectronic temperature sensitive signal-generating device of claim 11 wherein the component is a switch.