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- Lotfi, Sara, 1985-, et al.
(författare)
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Hybrid microtransmitter for free-space optical spacecraft communication : design, manufacturing, and characterization
- 2009
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Ingår i: Proc. SPIEPhotonics West, MOEMS and Miniaturized Systems VIII, Jan 24-29, San Jose, CA. - : SPIE. ; , s. 72080N-12-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Opticalintra-communication links are investigated by several currently operational qualification missions.Compared with RF communication systems, the optical domain obtains awider bandwidth, enables miniaturized spacecraft and reduced power consumption. Inthis project, a microtransmitter is designed and manufactured for formationflying spacecraft with transmission rates of 1 Gbit/s. Simulations inMatlab and Simulink show that a BER of 10-9 canbe achieved with aperture sizes of 1 cm and atransmitter output peak power of 12 mW for a distanceof 10 km. The results show that the performance ofthe communication link decreases due to mechanical vibrations in thespacecraft together with a narrow laser beam. A dual-axis microactuatordesigned as a deflectable mirror has been developed for thelaser beam steering where the fabrication is based on adouble-sided, bulk micromachining process. The mirror actuates by joints consistingof v-grooves filled with SU-8 polymer. The deflection is controlledby integrated resistive heaters in the joints causing the polymerto expand thermally. Results show that the mirror actuates 20-30°in the temperature interval 25-250°C. Flat Fresnel lenses made ofPyrex 7740 are used to collimate the laser beam. Theselenses are simulated in the Comsol software and optimized fora 670 nm red VCSEL. The lenses are manufactured usinglithography and reactive ion etching. All tests are made ina normal laboratory environment, but the effect of the spaceenvironment is discussed
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| 2. |
- Palmer, Kristoffer, 1983-, et al.
(författare)
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A micromachined dual-axis actuator for Use in a miniaturized optical communication system
- 2008
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Ingår i: Proceeding of the International Astronautical Congress, Sep 29 - Oct 3, Glasgow, Scotland.
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Konferensbidrag (refereegranskat)abstract
- A micromachined beam-steering device for use in a miniaturized free-space optical communication system is presented. This device is part of a communication system intended for microspacecraft flying in kilometer-sized formations. Central to it, is a laser-reflecting mirror tiltable in two orthogonal directions using electrothermal actuators based on heating of a polymer confined in silicon v-grooves. The device is fabricated using standard microstructure technology. Successful experiments show a maximum mechanical scan range of 19º in two orthogonal directions. The voltages applied are below 100 V, and the power consumption is less than 2.4 W. Thermal coupling between orthogonal joints has been investigated with infrared imaging. The overall results are very promising, and improvement in the design and fabrication can be suggested.
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