BD FACSymphony A3, User Manual

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User’s Guide 30
levels from 20 mW to 1000 mW might be available. Contact your
representative for more details.
Optical filters Optical filters attenuate light or help direct it to the appropriate
detectors. The name and spectral characteristics of each filter
appear on its holder.
There are two types of optical filters in the BD FACSymphony A3
and BD FACSymphony A5 flow cytometers:
• Longpass dichroic filters (LPs). Transmit wavelengths that are
longer than the specified value and reflect all light below the
specified wavelength.
• Bandpass filters (BPs). Pass a narrow spectral band of light.
When dichroic filters are used as steering optics to direct different
color light signals to different detectors, they are called dichroic
mirrors. LP dichroic mirrors transmit longer wavelengths to one
detector while reflecting shorter wavelengths to a different detector.
The flow cytometer detector arrays use dichroic longpass mirrors
on the inside, and bandpass filters on the outside of the filter
holders.