Last update: 2019/06/25 22:53 d2:spectroscopy_module_210 https://www.vescent.com/manuals/doku.php?id=d2:spectroscopy_module_210
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Printed on 2019/08/21 02:55
unit to the laser table.
Using the cable provided, connect the 8-pin circular Hirose connector to the D2-210 and
2.
connect the D-sub 9-pin connector to a free power connector on the D2-005 or other Vescent
electronics module. If you are using an alternate power supply, refer to the table above for
correct voltage input connections.
Connect the SMA connector to an oscilloscope.
3.
If you have the fiber-coupling option, connect a polarization maintaining fiber with FC/APC
4.
connector to the input fiber connector. At least 1 mW of optical power should exit the fiber.
Skip to step 9.
Note: When coupling the laser into the fiber, strive to
properly align the laser polarization to the polarization
axis of the PM fiber. Otherwise you will observe
significant temperature and stress induced birefringence
leading to input power fluctuations.
Open the top cover.
5.
Block the reference photodiode with a strip of index card.
6.
Adjust the light level by rotating the λ/2 waveplate to obtain about -1 V of signal.
7.
Shift the D2-210 about the mounting screws to maximize the light level.
8.
Set the laser to scan over the alkali transitions. If you observe spectroscopy, try to move the
9.
D2-210 to optimize the spectrum.
Tighten the 4 mounting screws.
10.
In about 20 min, a green LED should light (visible through the port next to SMA connector)
11.
indicating the final temperature has been achieved.
If the spectroscopy does not look similar to the plots shipped with the device, proceed to the
12.
Alignment Procedure below.
Use the Balance Adjust control to set the lock point to ground.
13.
Aligning the Spectroscopy Module
The spectroscopy module is shipped factory aligned and should not require alignment if ordered with
a matching D2-100-DBR laser or if ordered with the fiber input (-FC) option. If the unit was not aligned
to a laser at the factory, or if it falls out of alignment, the following steps can be used:
Fashion several 1 cm x 3 cm cards from an index card for use as viewing screens.
1.
Remove the cover on the Spectroscopy Module.
2.
If working with a Vescent D2-100 laser, follow the instructions in the
section
3.
to adjust laser steering so the beam passes through the center of the input and output
apertures on the laser module.
Adjust the λ/2 waveplate on the input face to maximize the light power reflected by the input
4.
PBS.
If required, loosen the two 2-56 screws holding the tilt-plate assembly into the spectroscopy
5.
module and slide the assembly so that the input beam is centered on the PBS.
Loosen the two cone screws using a 0.050“ Allen wrench. Then tighten the cone screw farthest
6.
from the alignment rod until the brass ring just begins to grab. Tighten the second cone screw
similarly. The goal is when moving the PBS with the alignment rod, it moves easily, but with
some resistance.
