THORLABS NanoTrak KNA-IR, Руководство пользователя Apt

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K-Cube NanoTrak Auto-Alignment Controller
Appendix C Principles of Operation
C.1 The NanoTrak
C.1.1 Introduction
For simplicity, the following example refers to the alignment of two opposing butt-coupled single mode fibers, however the
principles of operation are equally valid for the physical alignment of any two opposing optically coupled faces or indeed any
two objects that can provide a feedback signal (voltage) that varies as a function of their alignment with respect to each other. .
Fig. C.1 Alignment of optical fibers
In Fig. C.1, one of the fibers is fixed, the other is mounted on a piezo-actuated stage that moves the fiber in the horizontal and
vertical axes. The NanoTrak must adjust the position of the moving fiber until the power transmitted between the two is
maximized. Fig. C.2 shows a block diagram of the NanoTrak control loop. In many applications, a waveguide or similar device
replaces one of the fibers, however this makes no difference to the principle of operation.
Fig. C.2 NanoTrak control loop
vertical
horizontal
light
Auto
Piezo
Vertical
Horizontal
Piezo-actuated stage
Optical fibers
Detector
circuit
alignment
control
and
NanoTrak unit
amp
Piezo
control
and
amp