Title :
Actuating methods of quasistatic micromirrors for active focus variation
Author :
Conrad, Holger ; Klose, Thomas ; Sander, Thilo ; Schenk, Harald ; Lakner, Hubert
Author_Institution :
Semicond. & Microsyst. Technol. Lab., Tech. Univ. Dresden, Dresden, Germany
Abstract :
For zoom and focus applications in the UV and IR spectral range mirrors with actively deformable surfaces are promising for reflective adaptive optics as an alternative to refractive optics. To realise an adjustable focus length interval from infinity to the centimetre range the needed surface deformation can be described by a hemisphere. For shorter focus lengths and optical on-axis applications the parabolic shape has to be used. The actuation principle of a quasistatic micromirror with actively deformable surface can be realised using electrostatic, thermo-mechanic, piezoelectric or electromagnetic effects. This paper compares electrostatic, thermo-mechanic and piezoelectric actuation methods for deformable micromirrors. Thereby models of curved thin plates and estimations on power consumption for low frequency or quasistatic operation are discussed. Due to the low power consumption and the low driving voltage, the piezoelectric effect is determined as most promising driving principle for devices used in mobile applications.
Keywords :
adaptive optics; micro-optomechanical devices; microactuators; micromirrors; piezoelectric actuators; IR spectral range mirror; UV spectral range mirror; active focus variation; electromagnetic effects; low driving voltage; micromachined deformable mirror; mobile applications; optical on-axis applications; piezoelectric actuation method; piezoelectric effect; piezoelectric effects; power consumption estimation; quasistatic deformable micromirror; reflective adaptive optics; surface deformation; thermomechanical effects; Adaptive optics; Electrostatics; Energy consumption; Frequency estimation; H infinity control; Micromirrors; Mirrors; Optical refraction; Shape; Thermomechanical processes;
Conference_Titel :
Photonics and Microsystems, 2008 International Students and Young Scientists Workshop -
Conference_Location :
Wroclaw
Print_ISBN :
978-1-4244-4971-2
Electronic_ISBN :
978-1-4244-2555-6
DOI :
10.1109/STYSW.2008.5164131