Raman Spectrographs (5)

Question 1

Basic components of a spectrograph

Answer 1

input slit, input collimating optic, grating, output collimating optic, detector at output, focal plane

Question 2

Difference between a spectrograph and monochromator

Answer 2

spectrograph is a 2D device where separated wavelengths of spectrum are imaged simultaneously along horizontal axis at output focal plane; monochromator has an output slit with a single detector element, detecting only a single wavelength

Question 3

What is a Czerny-Turner spectrograph design?

Answer 3

2 concave mirrors and one planar diffraction grating; asymmetrical design produces flattened spectra, field

Question 4

What are some advantages of using a single spectrograph for raman?

Answer 4

simple, more efficient, more compact, cheaper

Question 5

What are some disadvantages of using a single spectrograph for raman?

Answer 5

lack adequate laser line and stray light rejection abilities

Question 6

What are some of the advantages of using a double spectrograph for Raman?

Answer 6

very good stray light rejection

Question 7

What are some of the disadvantages of using a double spectrograph for Raman?

Answer 7

relatively low throughput, not as useful with multichannel bc high dispersion reduces spectral coverage

Question 8

What are some of the advantages of using a triple spectrograph for Raman?

Answer 8

efficiently eliminates Rayleigh scattered light

Question 9

What are some of the disadvantages of using a triple spectrograph for Raman?

Answer 9

very low overall optical throughput

Question 10

What are some of the advantages of using a holographic spectrograph for Raman?

Answer 10

very high optical throughput, very good stray light rejection

Question 11

What are some of the disadvantages of using a holographic spectrograph for Raman?

Answer 11

fixed wavelength, fixed resolution