Aramis Raman Microscope
This manual is meant to complement your training and is not intended to replace on-the-job training.
WPC Activity Associated
Training Contact(s)
Emory Chan
emchan@lbl.gov
67-4114
x7373
Emergency Contact: 510-364-9962
Last Updated
10/12/2016
OPERATING PROCEDURE
1. Overview
1.Turn on instrument (Section 2)
2.Calibrate the desired grating to the laser wavelength and to the 520.7 cm-1 silicon Raman peak. (See p. 247 of the LabSpec manual v2.02 PDF)
3.Put sample in microscope or macro sample chamber (Section 3)
4.Take spectra (Section 4)
5.Map a sample if desired. (Section 5)
6.Turn off lasers.
7.Clean up after yourself!
8.Sign the log book!
2. Turning the system on/off
A. Turning ON
1. Fiber optic white light lamp (under laser table)
2. Laser
3. LabSpec software
B. Turning OFF
1. Turn off lasers & lamps
2. Evaporate all LN2 only if turning off NIR CCD power supply (optional)
3. Other modules do not need to be turned off.
4. Sign log book!
3. Setting up Macro sample chamber
The Macro sample chamber is used for large samples that do not need to be placed under a microscope. This is mainly for homogeneous liquid samples or solid samples.
1. Click the Setup button in the ARAMIS control panel box (see Section 6)
2. In the “Measure Location” box, choose Macro 90 deg for liquids or retro (180 degrees) for solids.
3. Change the video camera with Menu:Video > Camera Macro to see the laser spot while in “retro” 180 degree mode. Adjust XYZ knobs until laser is in center. With the RTD on, rotate the focus wheel to maximize signal.
4. Taking Spectra
1.Open the default configuration:
a. On the top icon bar in the middle, click the button called “Configurator." The button icon looks like a light blue sheet of notepad with a "+" sign. It's next to the video camera button.
b. Click the "Load" button and load the file path: "My Documents/Config/Default config.ngp". This will reset the software to settings familiar for most Raman users.
2.Turn on live camera with the video button on the top tool bar. Turn on the reflection fiber light.
3.Lower the microscope stage and load your sample.
4.Turn the microscope to the 10x objective
5.Focus using (stiff) coarse knobs on the left side of the microscope
6.Look for fiber bundle reflection. When the image on screen gets brighter, you are getting closer to focus.
7.Fine focus by rotating the joystick knob.
8.Change to desired objective. If using the 100X objective, BE CAREFUL NOT TO CRASH THE OBJECTIVE INTO YOUR SAMPLE. If using the 1064 laser, use the 100x Leica NIR objective. Use the joystick knob to focus so as not to crash the objective.
9.Stop video camera clicking the stop button (upper right)
10. Set values in control panel (lower toolbar, pictured above). See Section 6 for more detailed information.
a. Set laser wavelength. See Section 8 for laser selection considerations.
b. Set ND filter.
c. Set hole diameter (aperture). 50 µm for high resolution, 200-300 µm for homogeneous samples (low resolution, better signal).
d. Set spectrometer field to center of desired cm-1 range.
e. Set options box
i. Set grating to appropriate grooves/mm. See Section 9 for gratings details.
ii. Set Objective to appropriate magnification (e.g. 100x) IMPORTANT!!! Scale bars will be incorrect if you forget this step !
iii. Set data name if you want a prefix for your files.
f. Set acquisition times:
i. Set RTD exposure time (s), exposure time (s), and # of samples to average.
11. Set the detector (Vis or NIR) in Menu: Acquisition > Detector >Sensor
g. If you changed the detector, set the shutter switch on the left side of the ARAMIS box to the right shutter. (Shutter 1/up) Synapse VIS CCD, (Shutter 2/down) NIR IGA Symphony detector.
12. Click on the “Spectrum RTD” button to take a live spectrum. Adjust focus, ND filter, hole, and acquisition time to optimize signal.
13. If the x-axis units on the spectrum are not correct (e.g., nm instead of cm-1), you can change them in Menu: Options > Units…
14. Click on the extended range button (three humps) to have the detector take a spectrum over a wider wavenumber range.
15. Click the Spectrum Acquisition piggy bank icon to acquire a spectrum.
5. Setting up a mapping experiment
6. The Control Panel
Going left to right, set the appropriate values in the control panel at the bottom of the LabSpec window.
7. Lasers
Choose the appropriate laser for your sample. Scattering is proportional to 1/(excitation wavelength)4, and the NIR detector is not as sensitive as the visible CCD, so ideally you would want to use the shortest wavelength possible (e.g. the 532 nm laser). Some samples (e.g. organic samples) may exhibit too much absorption or fluorescence at shorter wavelengths, so your next option should be the 785 nm laser. The 1064 nm laser is used mainly for photoluminescence or for extreme cases to avoid absorption or PL.
8. Gratings
Choose the appropriate grating given the laser wavelength, your desired spectral resolution, and your desired spectral range. For maximum efficiency, one should match the laser wavelength at which the wavelength that the laser was blazed. Increasing the groove density increases the resolution, increases accuracy, and decreases intensity.