Cypher SPM
User Guide
15
15
Light Tubes
The following instructions describe exchanging the light tube assembly in the Cypher AFM. The
light tube can be exchanged without disassembly through the front of the instrument when you
have some experience of the process. For clarity the instructions describe exchanging the light tube
by disassembling the enclosure followed by the process done through the front of the instrument.
15.1 Types of light tube and how to identify them
The Cypher has two types of light source:
l
Laser diodes:
The best all around choice for AFM imaging. They have lower noise for imaging
techniques, but some interference effects which can lead to background oscillations when per-
forming force curve measurements.
l
Super luminescent diodes:
Also known as SLDs, these are the best all around choice for force
curve measurements. They have slightly higher noise than laser diode sources, but lower back-
ground oscillations for force curve measurements.
Each light source comes in two sizes:
l
Small spot:
3 µm by 9 µm spot size. Mandatory for cantilevers smaller than the standard spot,
to prevent light from spilling over the sides.
l
Standard spot:
10 µm by 30 µm spot size. Preferable for larger (traditional) cantilevers since a
spot that fully fills the cantilever leads to lower imaging noise.
The following table identifies the light sources and their part numbers.
15 Light tubes
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