Princeton Instruments PhotonMAX System, Manual, Page: 39 / 98

Chapter 5 Operation 39
4. In WinSpec, select
Focus
(on the Acquisition menu or on the Experiment
Setup dialog box) to begin data accumulation. Data will be continuously
acquired and displayed but will not be stored until you stop acquisition and use
the
Save
function on the File menu.
5. Slowly move the camera in and out of focus. You should see the spectral line go
from broad to narrow and back to broad. Leave the camera set for the narrowest
achievable line. You may want to use the
Focus Helper function
(
Process|Focus Helper…
) to determine the narrowest line width: it can
automatically locate peaks and generate a report on peak characteristics during
live data acquisition (see the WinSpec/32 on-line help for more information).
Note that the way focusing is accomplished depends on the spectrograph, as
follows:
•
Long focal-length spectrographs such as the Acton SP-2356:
The mounting adapter includes a tube that slides inside another tube to
move the camera in or out as required to achieve optimum focus.
•
Short focal-length spectrographs:
There is generally a focusing
mechanism on the spectrograph itself which, when adjusted, will move
the optics as required to achieve proper focus.
•
No focusing adjustment:
If there is no focusing adjustment, either
provided by the spectrograph or by the mounting hardware, then the only
recourse will be to adjust the spectrograph’s focusing mirror.
6. Next adjust the rotation. You can do this by rotating the camera while watching a
live display of the line. The line will go from broad to narrow and back to broad.
Leave the camera rotation set for the narrowest achievable line.
Alternatively, take an image, display the horizontal and vertical cursor bars, and
compare the vertical bar to the line shape on the screen. Rotate the camera until
the line shape on the screen is parallel with the vertical bar.
Note:
When aligning other accessories, such as fibers, lenses, optical fiber adapters,
first align the spectrograph to the slit. Then align the accessory without disturbing the
camera position. The procedure is identical to that used to focus the spectrograph
(i.e., do the focus and alignment operations while watching a live image).