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SolsTiS User Manual v10.0
4.
NOTE
– the following HOME page status indicators:
a.
‘Temperature’ indicates the reference cavity temperature
indicator, and will be red/ show out of lock until the reference
cavity heats up to the correct temperature (e.g., ~40ºC), which
may take up to ~30 minutes. This behaviour is normal, does not
indicate a fault, and will not prevent use of the laser.
b.
The ‘Output Monitor’ is a relative output power monitor, and
typically reads ~1-2V when operating normally. This (wavelength
dependent) photodiode detector is mounted inside the SolsTiS
laser head, except in the SolsTiS-SRX with reference cavity, in
which case this photodiode is mounted inside the reference cavity
housing, and used to normalize out output power fluctuations on
the reference cavity photodiode.
c.
‘Align Status’ (APAM automated pump alignment module only)
indicates optimal pump beam alignment (maximum output power)
has been achieved by the APAM. This indicator should be ignored
if the APAM is not fitted (in which case, Alignment X, Y will display
0V).
5.
Carefully increase the pump power to that noted in the Final Test Sheet
for your system in Appendix C. Make a note of SolsTiS’ set wavelength,
as shown on the ‘Wavelength’ monitor on the UI HOME page, and
compare the measured output power at this wavelength to the Final Test
sheet. Try small POM X,Y pump beam adjustments (<
1/4 turn) if the
measured output power appears significantly lower than the Final Test
Sheet.
5.2
Wavelength Tuning & Scanning
Coarse Wavelength Tuning
– Adjusting the Intracavity BRF
Using the
BRF Tune
+/- radio buttons on the laser CONTROL page of the UI,
is possible to set the SolsTiS output wavelength to within approximately one
étalon FSR or better of the required wavelength of interest (0.15-0.7nm,
depending on the SolsTiS model purchased). This wavelength tuning control
has an acceleration algorithm that will speed up the tuning process
the longer this button is held down.
Note!
SolsTiS includes a proprietary
WSD
onboard
wavelength monitor that provides a UI readout of
SolsTiS’ output wavelength, without the need for an
external spectrometer. The precision of the WSD is
generally sufficient for coarse wavelength
adjustments with the BRF. If, however, a higher
precision wavelength readout is needed (when
adjusting SolsTiS’ frequency via the étalon adjust, for
example) a higher precision external spectrometer or
wavemeter is recommended.
Note!
It is possible to tune the BRF beyond a region
of smooth tuning that covers the range shown in the
Final Test Sheet (see Appendix C). Attempting to
tune outside this region is not recommended, as
SolsTiS will enter an arbitrary tuning space and may
also stop lasing. (In this case, the tuning direction
should be reversed until the SolsTiS output
wavelength is back within the tuning region shown on
the Final Test Sheet.)
To tune SolsTiS’ wavelength with the BRF:
1.
Start with the BRF tuning speed set to MEDIUM, as faster
tuning speeds can make it easy to over shoot the required
wavelength, or speed through to another BRF order. When
tuning the BRF, the output wavelength will change in discrete
jumps of one étalon FSR.