Femtowatt non-vacuum tube detector assembly
In one embodiment, a femtowatt sensitivity optical detector is provided using one or more photodiodes, intended as a replacement for the photomultiplier based photon counting unit.
1. A device comprising:
a plurality of photodiodes;
an analog amplification system comprising at least a high gain transimpedance amplifier (TIA) and at least a buffer on each of said photodiodes, followed by a fully differential amplifier to combine outputs of multiple TIAs;
a digital acquisition system comprising at least one analog-to-digital converter (ADC), followed by a programmable processor, which is linked to a central processor as well as on-board memory; and
at least one shaped reflector to direct light to at least one of said photodetectors, wherein the shaped reflector comprises at least one opening sized and positioned to allow a sample vessel to be placed at a desired location in a cavity defined at least in part by the shaped reflector.
2. The device of claim 1 further comprising a mechanical housing module of the analog amplification system are contained.
3. The device of claim 1 wherein the programmable processor implements the data acquisition algorithm.
4. The device of claim 1 further comprising multiple digital-to-analog converters (DACs) on the programmable processor configured to provide feedback control.
5. The device of claim 4 wherein one of said DACs is configured for offset adjustment in the differential amplifier, and one of said DACs is set the reference level of the ADC.
6. The device of claim 1 wherein the shaped reflector has a semi-hemispherical shape.
7. The device of claim 4 , wherein one of the DACS is configured for offset adjustment in the differential amplifier.
8. The device of claim 4 , wherein one of the DACS is configured to set a reference level of the ADC.
9. The device of claim 5 , wherein one of the DACS is configured for offset adjustment in the differential amplifier.
10. The device of claim 5 , wherein one of the DACS is configured to set a reference level of the ADC.
11. The device of claim 3 , wherein data acquisition algorithm uses the following digital signal processing: smoothing data processing.
12. The device of claim 3 , wherein data acquisition algorithm uses the following digital signal processing: Savitzky-Golay smoothing.
13. The device of claim 3 , wherein data acquisition algorithm uses the following digital signal processing: moving average smoothing.
14. The device of claim 3 , wherein data acquisition algorithm uses the following digital signal processing: local regression smoothing.
15. The device of claim 3 , wherein data acquisition algorithm uses the following digital signal processing: recursive filter median.
16. The device of claim 3 , wherein data acquisition algorithm uses the following digital signal processing: long time average.
17. The device of claim 3 , wherein data acquisition algorithm uses the following digital signal processing: Butterworth filtering.
18. The device of claim 3 , wherein data acquisition algorithm uses the following digital signal processing: Kalman filtering.
19. The device of claim 3 , wherein data acquisition algorithm uses the following digital signal processing: Kernel smoothing.
20. The device of claim 3 , wherein data acquisition algorithm uses the following digital signal processing: Laplacian smoothing.