Ocean Optics MMS Raman - Manual (Page 23)

B: Introduction to Multimodal Sampling
The etendue for a slit based spectrometer achieving the same resolution is:
Etendue (Slit) = 2N x 1 x Ω
and for a fiber input-based spectrometer, the etendue is:
Etendue (Fiber) = 1 x 1 x Ω
Therefore,
/ 2 MMS
Slit
E
N
E
=
and
2 MMS
Fiber
E
N
E
=
Typical MMS implementations use proprietary coding schemes that range in order from N=16-48. That
translates to an etendue advantage of 8-24X compared to slit based spectrometers or 256-2304X
compared to fiber based spectrometers. This is illustrated in Figures 4 and 5.
Figure 5: Etendue advantage of
MMS compared to a pin hole.
Figure 4: Etendue advantage of
MMS compared to a binned slit.
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