Dynamic performance of MEMS deformable mirrors for use in an active/adaptive two-photon microscope
| Autor: | Christopher L. Arrasmith, Ryan D. Downey, David L. Dickensheets, Christian C. Zhang, Warren B. Foster |
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| Rok vydání: | 2016 |
| Předmět: |
Physics
Wavefront Settling time business.industry Zernike polynomials Coma (optics) Active optics 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Deformable mirror 010309 optics symbols.namesake Spherical aberration Optics 0103 physical sciences symbols 0210 nano-technology business Adaptive optics |
| Zdroj: | Adaptive Optics and Wavefront Control for Biological Systems II. |
| ISSN: | 0277-786X |
| DOI: | 10.1117/12.2216331 |
| Popis: | Active optics can facilitate two-photon microscopic imaging deep in tissue. We are investigating fast focus control mirrors used in concert with an aberration correction mirror to control the axial position of focus and system aberrations dynamically during scanning. With an adaptive training step, sample-induced aberrations may be compensated as well. If sufficiently fast and precise, active optics may be able to compensate under-corrected imaging optics as well as sample aberrations to maintain diffraction-limited performance throughout the field of view. Toward this end we have measured a Boston Micromachines Corporation Multi-DM 140 element deformable mirror, and a Revibro Optics electrostatic 4-zone focus control mirror to characterize dynamic performance. Tests for the Multi-DM included both step response and sinusoidal frequency sweeps of specific Zernike modes. For the step response we measured 10%-90% rise times for the target Zernike amplitude, and wavefront rms error settling times. Frequency sweeps identified the 3dB bandwidth of the mirror when attempting to follow a sinusoidal amplitude trajectory for a specific Zernike mode. For five tested Zernike modes (defocus, spherical aberration, coma, astigmatism and trefoil) we find error settling times for mode amplitudes up to 400nm to be less than 52 us, and 3 dB frequencies range from 6.5 kHz to 10 kHz. The Revibro Optics mirror was tested for step response only, with error settling time of 80 μs for a large 3 um defocus step, and settling time of only 18 μs for a 400nm spherical aberration step. These response speeds are sufficient for intra-scan correction at scan rates typical of two-photon microscopy. |
| Databáze: | OpenAIRE |
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