THORLABS M2MS, Руководство по эксплуатации

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BP209 Series 7 Operation Instructions
Rev: 8.1, 14-Feb-2022 © 2022 Thorlabs Page 79
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astigmatism
Note
The Thorlabs Beam Quality measurement tool can handle CW sources and some pulsed
sources! For more information about pulsed laser sources read chapter
Pulsed Laser
Sources .
7.2.2 M2MS Operating Principle
The Thorlabs M2MS M² Meter System is a compact instrument that includes all components re-
quired to measure beam quality:
j
Beam Profiler (not shown below)
k
Linear Translation Stage Thorlabs DDS100
l
Lenses with different AR coatings, suitable for different wavelengths to be analyzed
m
Lens centering assembly (X-Y translation mount)
n
2 tilted mirrors
Adjustment Laser (not shown below)
o
Integrated control electronics (translation stage controller, USB 2.0 hub and driver for
alignment laser)
The beam under test enters the the focal lens (3), hits the two tilted mirrors (5) and leaves the
enclosure towards the Beam Profiler's input aperture (1). The translation stage is moved step-
wise by the control software, and in this way changes the path length between the focal lens
and the Beam Profiler. The maximum travel range of the stage (100 mm) is doubled by the use
of two mirrors. The resulting path length range is 200 mm. The focal length of the lens is selec-
ted in such a way that the beam waist will be close to the middle of the travel range.
During the M² measurement, the stage moves stepwise along the beam propagation direction
and at each position the beam geometry is measured. From the results, the software calculates
beam parameters and beam quality.
The mirrors are factory aligned; there is no need to re-align them.
For fine beam alignment, an alignment laser is supplied. Please see section Beam Align-
ment for details.
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