Detector array and cross-talk linearity connection

• US 20060202124A1
• Filed: 02/01/2006
• Published: 09/14/2006
• Est. Priority Date: 08/29/2000
• Status: Active Grant

• Current Assignee: PerkinElmer Singapore Pte Ltd. (Revvity, Inc.)
• Original Assignee: PerkinElmer Singapore Pte Ltd. (Revvity, Inc.)
• Inventors: Turner, Andrew James, Hoult, Robert Alan
• Granted Patent: US 7,560,697 B2
• Time in Patent Office: Days
• US Class Current: 250/349
• CPC Class Codes: G01J 3/2803 using photoelectric array detector
• CPC Class Codes: G02B 21/0096 with photometer devices photometers per se G01J

Abstract

An infrared imaging microscope, particularly of the type used to carry out FT-IR measurement, including a detector in the form of a relatively small detector array of individual detector elements. The outputs of the detector elements are fed in parallel to an electronic circuit for processing. The relatively small array allows the outputs to be processed without need for multiplexing thereby avoiding reduction in signal-to-noise. The detector array may substantially range from about 3 to about 100 detector elements, and is preferably in a range from about 16 to about 64 detector elements.

Claims

1. An IR microscope for directing radiation on a sample to be analyzed, the IR microscope comprising:

a detector having an array of individual detector elements, each detector element having a detector element output;

a detection circuit coupled to each detector element output, said detection circuit including;

an amplifier for receiving the detector element output and generating an amplified output signal;

a summation device coupled to said amplifier and receiving the amplified output signal; and

a feedback loop directing an output signal of the summation device to said amplifier.

2. The IR microscope according to claim 1, wherein each detector element is operated in a constant voltage mode or constant current mode.

3. The IR microscope according to claim 2, wherein each detector element has a common lead in combination with an amplifying stage which has feedback which acts to minimize crosstalk between the signals of the detector elements.

4. The IR microscope according to claim 1, further comprising processing circuitry including:

an amplifier for amplifying the outputs of the array of detector elements; and

an analog-to-digital converter for digitizing the amplified outputs of the array of radiation detectors.

5. The IR microscope according to claim 4, wherein each detector element output is fed in parallel to said processing circuitry.

6. The IR microscope according to claim 4, further comprising a processor for processing the digitized signals.

7. The IR microscope according to claim 6, wherein the processor is arranged to apply a linearity correction to the digital signals according to the following algorithm:

y′

=y/(1−

α

y)

where y is the output of the analogue-to-digital converter, y′

is the corrected output, and α

is a parameter.

8. The IR microscope according to claim 7, wherein the parameter α

is a constant.

9. The IR microscope according to claim 7, wherein the parameter α

is a function of energy incident on the detectors.

10. The IR microscope according to claim 4, wherein the analog-to-digital converter is arranged to operate by oversampling the amplified outputs.

11. The IR microscope according to claim 1, further comprising a single detector element and a processor arranged to process output signals received from either the array or the single detector element.

12. An IR microscope for directing radiation on a sample to be analyzed, the IR microscope comprising:

a detector having an array of individual detector elements, each detector element having a detector element output;

a detection circuit including, a summation device receiving the output from the detector element and a feedback loop directing at least a portion of an output signal of the summation device to said amplifier.

13. The IR microscope according to claim 12, wherein a detection circuit is provided for each detector element output.

14. The IR microscope according to claim 12, further comprising an amplifier for receiving the detector element output and generating an amplified output signal to be fed to the summation device.

15. The IR microscope according to claim 12, further comprising processing circuitry including:

an amplifier for amplifying the outputs of the array of detector elements; and

an analog-to-digital converter for digitizing the amplified outputs of the array of radiation detectors.

16. The IR microscope according to claim 15, wherein each detector element output is fed in parallel to said processing circuitry.

17. The IR microscope according to claim 15, further comprising a processor for processing the digitized signals.

18. The IR microscope according to claim 17, wherein the processor is arranged to apply a linearity correction to the digital signals.

19. The IR microscope according to claim 18, wherein the linearity correction is calculated according to the following algorithm:

y′

=y/(1−

α

y)

where y is the output of the analogue-to-digital converter, y′

is the corrected output, and α

is a parameter.

20. The IR microscope according to claim 19, wherein the parameter α

is a constant.

21. The IR microscope according to claim 19, wherein the parameter α

is a function of energy incident on the detectors.

22. The IR microscope according to claim 12, wherein each detector element is operated in a constant voltage mode or constant current mode.

23. An IR microscope for directing radiation on a sample to be analyzed, the IR microscope comprising:

a detector having an array of individual detector elements substantially in a range from about 3 to about 100 detector elements, each detector element having a detector element output;

an electronic circuit simultaneously receiving said detector element outputs in parallel;

each of said detector element outputs coupled to a portion of said electronic circuit dedicated to the respective detector element.

24. The IR microscope according to claim 23, wherein the range is substantially from about 16 to about 64 detector elements.

25. The IR microscope according to claim 23, wherein each detector element is operated in a constant voltage mode or constant current mode.

26. The IR microscope according to claim 25 wherein each detector element has a common lead in combination with an amplifying stage which has feedback which acts to minimize crosstalk between the signals of the detector elements.