Digital holographic two-wavelength contouring of high speed MEMS using ultrashort laser pulses
Conference: MikroSystemTechnik - KONGRESS 2007
10/15/2007 - 10/17/2007 at Dresden, Germany
Pages: 4Language: englishTyp: PDFPersonal VDE Members are entitled to a 10% discount on this title
Hansel, Thomas; Steinmeyer, Günter; Grunwald, Rüdiger; Griebner, Uwe (Max-Born-Institut, Max-Born-Strasse 2a, D-12489 Berlin, Germany)
Falldorf, Claas; Kopylow, Christoph von (Bremer Institut für angewandte Strahltechnik BIAS, Klagenfurter Str. 2, D-28359 Bremen, Germany)
Bonitz, Jens; Kaufmann, Christian (Technische Universität Chemnitz, Reichenhainer Str. 70, D-09107 Chemnitz, Germany)
Single-shot digital holographic shape measurements of high-speed MEMS using femtosecond laser pulses are reported. To perform contouring of very fast moving objects the simultaneous generation of at least two spectrally separated ultrashort pulses is required. A chirped-pulse Ti:sapphire laser amplifier was modified to emit two femtosecond pulses of high spectral contrast at a separation of 10-15 nm. A Michelson-type interferometer was employed to perform stroboscopic two-wavelength-contouring. To record the two holograms of the MEMS with a resonance frequency of 0.5 kHz at once a multiplexing technique is applied. The phases of the holograms and the difference phases are numerically calculated. The resulting image contains a fringe pattern which allows to deduce the contour lines of the topology of the MEMS. Measurements of dynamic deformation at the MEMS resonance frequency are presented.