2. General Description
28
IFU for Infinite 200 PRO No. 30052730 Rev. No. 1.6
2016-04
Fluorescence Top/Bottom Optics
Flash light enters the optical system and is focused by the condenser onto the
entrance slit of the Excitation Monochromator. The wavelength of the excitation
light is selected within the monochromator. After passing the monochromator, the
excitation light is coupled into a fiber bundle, which guides the light to the top or
bottom measuring head. The light is then focused into the sample by the
top/bottom lens system.
The fluorescence light is collected by the top/bottom lens system again, coupled
into the fluorescence fiber bundles and guided to the detection system.
The Fluorescence Measuring Optics Top is built from the following components:
•
Fluorescence Intensity Lens System Top
•
Fluorescence Fiber Bundle
•
The bottom optics consists of the following components:
•
Fluorescence Bottom Mirror
•
Fluorescence Fiber Bundle
Fluorescence Intensity Lens System Top
The exit side of the bundle acts as a color specific light source. The lens system
at the end of the excitation top fiber is designed to focus the excitation light into
the sample, and also collect the fluorescence light and focus it back onto the
fluorescence fiber bundle.
The objective lenses are made from fused silica. This material provides high UV
transmission and is virtually void of auto-fluorescence.
Excitation Spot Size
The size of the fiber bundle cross section determines the diameter of the beam
waist (spot size) in the microplate well. The spot diameter for the M-series is
about 3 mm for the top optics and 2 mm (standard) or 4 mm (enhanced) for the
bottom optics.
Fluorescence Fiber Bundle Top and Bottom
The fiber bundle plugged into the top/bottom measuring head contains a
homogeneous mixture of both excitation and emission fibers. The emission fibers
guide the fluorescence light emission monochromator head where a lens system
focus the light onto the entrance slit of the Emission Monochromator.
Fluorescence Bottom Mirror
The exit side of the bundle acts as a color specific light source. The mirror at the
end of the excitation bottom fiber is designed to focus the excitation light into the
sample and also collects the fluorescence light and focuses it back onto the
fluorescence fiber bundle.
Z-Positioning (Fluorescence Top on Infinite M200 PRO only)
The height of the objective above the sample can be adjusted using the Z-
position function. As excitation light is reflected by the sample fluid, z-adjustment
helps to maximize the signal-to-noise ratio. For further details about z-positioning
see chapter 5.5.2 Z-Optimization (FI Top measurements with the Infinite M200
PRO only).
