Raman Detectors (5)

Question 1

What are the characteristics needed for a Raman detector?

Answer 1

high quantum efficiency, low dark signal so weak raman signals are buried in dark noise

Question 2

How do multichannel detectors compare with single channel detectors?

Answer 2

Multichannel does Multiple readings at once so binning is used to average signal vertically to increase signal strength

Question 3

Useful wavelength region of single channel raman detectors

Answer 3

UV/Vis

Question 4

Physical principle behind single channel detector response

Answer 4

phototubes: photosensitive cathodes, collection anode, separated by dynodes

Question 5

Advantages of single channel

Answer 5

very useful for low power, very fast response time

Question 6

Disadvantages of single channel

Answer 6

sensitivity limited by dark current, needs cooling, damaged by intense light, low quantum efficiency

Question 7

Spectroscopic usefulness of PMT as a detector

Answer 7

Raman, fluorescence

Question 8

The useful wavelength region of multi-channel raman detectors

Answer 8

UV, Vis, NIR

Question 9

Physical principle behind multi-channel detector response

Answer 9

photons strike MOS-on-p-type-Si capacitor, electron charge stored in wells

Question 10

Advantages of multi channel detectors

Answer 10

multichannels, high quantum efficiency

Question 11

Disadvantages of multichannel detectors

Answer 11

possible spurious signals because of radioactive decay, complicated readout

Question 12

spectroscopic usefulness of CCD as a detector

Answer 12

spectroscopy, imaging