Zeiss LSM 880, Руководство по эксплуатации

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II
Optical Coordinates
Analogously, a sensible way of normalization in the axial
direction is in terms of multiples of the wave-optical depth
of field. Proceeding from the Rayleigh criterion, the follow-
ing expression is known as Rayleigh unit (RU):
The RU is used primarily for a generally valid repre sentation
of the optical slice thickness in a confocal LSM.
In order to enable a representation of lateral and axial quan-
tities independent of the objective lens used, let us intro-
duce optical coordinates oriented to microscopic imaging.
Given the imaging conditions in a confocal microscope,
it suggests itself to express all lateral sizes as multiples
of the Airy disk diameter. Accordingly, the Airy unit (AU)
is defined as:
The AU is primarily used for normalizing the pinhole
diameter.
Thus, when converting a given pinhole diameter into AUs,
we need to consider the system’s total magnification; which
means that the Airy disk is projected onto the plane of the
pinhole (or vice versa).
n = refractive index of immersion liquid
with NA = 1.3,
λ 
= 496 nm and n = 1.52 → 1RU = 0.446 µm
n
.
NA 2
1AU =
seite II 1.22
.
NA
1RU =
seite V
SNR N
Poisson
= N
N =
photons
QE
( )
.
pixel time
N = se
.
(N+N
d
) (1+q
2
)
SNR =
N 2
se
2
(N+N
d
) (1+q
2
)
SNR =
1000 2
1.2 2 (1000+100) (1+0.05 2 )
= 25.1
n
.
NA 2
1AU =
seite II 1.22
.
NA
1RU =
seite V
SNR N
Poisson
= N
N =
photons
QE
( )
.
pixel time
N = se
.
(N+N
d
) (1+q
2
)
SNR =
N
2
se 2 (N+N
d
) (1+q 2 )
SNR =
1000 2
1.2 2 (1000+100) (1+0.05 2 )
= 25.1
PART 3
Details
NA = numerical aperture of the objective
λ

= mean wavelength
with NA = 1.3 and λ  = 496 nm → 1AU = 0.465 µm