ThermoMicroscopes Aurora-2, User Manual

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URORA

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VERVIEW

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Aurora-2 User’s Manual

Note that once the tip has been coupled to the laser, thermal expansion of the tip will take 
place for the next few minutes.  It is a good idea to wait approximately 15 to 20 minutes 
before attempting a scan, to allow the tip to reach thermal equilibrium. 

O

PTICAL

 T

RAIN

A

LIGNMENT

The Aurora-2’s optical train has been adjusted at the factory, and the service representative 
who installed the system has made final adjustment corrections.  However, the user should 
be able to make adjustments to the optical path if necessary.

The objective of this procedure is to have the center of the optical beam pass through the 
center of each optical element in its path.  This means that the image beam should be 
centered on both the transmission and reflection lenses, the beam mirrors, the prisms, the 
focusing lenses, and the CCD camera and PMT detector faces (see Figure 2-2 on page 2).  
This is essentially the same goal as in any optical system, and the procedures for achieving 
this goal are similar.

Precise optical adjustment is critical for NSOM imaging and any advanced techniques.  
Because the tip emits little light, the optical path must be accurately focused to collect the 
maximum amount of light with the detector.  If the detector signal strength is very low, 
make sure that none of the beam is being lost along the path and that the beam is focused 
on the detector.

For this procedure, you will need a small piece of paper to use as a “beam finder.”  The back 
of a business card or index card works well for this.

CAUTION

  Keep the PMT Voltage on the Aurora Control Unit set to 0, unless the PMT 

is shielded from all sources of light (except the laser during NSOM imaging).  Exposure to 
light can damage the PMT.  The voltage should only be turned up when carefully following 
the procedures in Chapter 4.

Step 1

Set up the Aurora-2 as described in the above procedures in this chapter.  It is 
assumed that the user is familiar with removing and replacing the head and 
mounting a sample.

Step 2

If the system is not powered up, first turn on the ECU-Plus, then the computer and 
the video monitor.  (The ECU-Plus should always be turned on before the 
computer so that the ECU interface is recognized and initialized.)

Step 3

Open the SPMLab software, and enter the Data Acquisition module.

Step 4

Turn on the light on the Aurora-2 head with the switch on the Aurora Control Unit.  
This light illuminates the sample during tip positioning and focusing.

Step 5

Remove the head from the stage, if necessary.

Step 6

Mount the ThermoMicroscopes NSOM standard sample on the stage.  The easiest 
way to do this is by using a few small pieces of tape at the corners of the sample.  
Or, you can put a small drop of immersion oil underneath the sample.

Step 7

Turn the Z-height thumbscrews on the head one full turn clockwise, and carefully 
place the Aurora-2 head on the stage, lowering the head slowly to make sure the 
tip does not touch the sample when it comes to rest in the kinematic mount.  The 
tip should now appear in the video monitor.