Characterization of laser thermal loading on microelectromechanical systems-based fast steering mirror in vacuum
Name
056109_1.pdf
Description
Published version
Size
7.53 MB
Format
Adobe PDF
Checksum (MD5)
6caaeb7d475a745a8ed9055d827565de
Author(s)
do Vale Pereira, Paula
Hunwardsen, Matthew T
Cahoy, Kerri
Date Issued
2020
Journal
Optical Engineering
Publisher
SPIE-Intl Soc Optical Eng
Version
Final published version
Abstract
© The Authors. Microelectromechanical systems (MEMS) have produced high-quality, high-bandwidth, small form factor, and inexpensive fast steering mirror (FSM) devices potentially suitable for a large variety of applications, such as image stabilization and beam pointing in satellite-based and ground-based, free-space optical communication systems. However, one outstanding question for this application is power handling. The absorption of the mirror substrate is low, but non-negligible, so the question remains of whether thermal loading from laser radiation on a MEMS mirror will deform its surface and, if so, to what extent. We show experimental results of optical performance changes due to thermal loading for MEMS two-axis FSM devices from Mirrorcle Technologies, Inc. Results and reproducible behavior are reported and compared in ambient versus vacuum conditions, where the benefits of convective cooling are absent. Finite element analyses corroborate the experimental results and show that the mirror substrate can deform due to thermal expansion imbalances. The deformation changes the focusing characteristics of the mirror, with a peak to valley defocus (second-order Zernike mode) of up to 50 nm when the mirrors are tested in ambient and up to approximately 450 nm when under vacuum. Such defocusing negatively impacts the link budget for laser-based satellite communications.
MIT Department
Massachusetts Institute of Technology. Department of Aeronautics and Astronautics
Space Telecommunications Astronomy and Radiation (STAR) Lab
Terms of Use
Creative Commons Attribution 4.0 International license
Persistent DSpace Link
DOI of Published Version
10.1117/1.OE.59.5.056109
