SmarAct PICOSCALE, Руководство пользователя

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3 PICO SCALE FUNDAMENTALS
The PICO SCALE is a powerful system for optical and non-invasive displacement and vibration
measurements. The three channel system is based on a miniaturized Michelson interferometer.
The system features powerful interfaces and
fl exible software modules. Due to useful accessories
the system can be adapted to speci fi c needs. The
PICO SCALE
GUI allows to operate the system
out of the box. In summary , these versatile characteristics make the PICO SCALE a very powerful
tool for every lab!
3.1 General setup and basic components
Each
PICO SCALE
measurement setup requires a few basic components. The
PICO SCALE
con-
troller is the core component. I n the controller, coherent light is generated by a laser diode. A
fi ber network distributes the laser light into three output channels.
Sensor head
Reference
mirror
Target mirror
Working distance
Optical fiber
PICO SCALE
Figure 3.1: Basic setup of a PICO SCALE displacement measurement. Miniaturized sensor heads
are connected to the PICO SCALE controller via optical fi bers. The system measures
the displacements of a target mirror relative to the sensor head.
Up to three sensor heads can be connected to the controller via optical FC/APC-terminated fi bers.
Within the sensor head, the laser light is divided into a reference and a measurement beam by
a beam splitter, being the central component of a Michelson interferometer.
I n standard sensor
heads one side of the miniaturized beam splitter cube is coated with a re fl ective coating, which acts
as reference mirror. The measurement beam exits the head and is re fl ected by the measurement
target, which can be a mirror, a piece of glass or almost any other technological relevant surface.
Both, the re
fl ected reference and measurement beam interfere in the center of the beam splitter
cube and the combined light is guided back to the controller. Due to advanced signal processing
methods, based on lock-in detection and fast FPGA based evaluation algorithms, the
PICO SCALE
is able to measure target mirror displacements with single picometer resolution and sample rates
of up to 10 MHz.
16 PicoScale User Manual