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The purpose of daoSPIM system is imaging a sample inside microfluidic device using light-sheet illumination and dual-view detection . The design allows simultaneous imaging from two directions (views) using a single camera sensor, by combining the two optical paths into one. This is achieved by using a knife-edge mirror (M-prism) between the arms. The figure below shows simplified arrangement in 3d (a), detailed optical layout (b), and a zoom-in of detection and excitation light rays as they pass through the glass coverslip (c).
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Due to the left-right symmetry of the optical train, images from both left and right objective are projected on the camera sensor simultaneously without any mechanical switching.
The optical design puts the pupil planes of the two objectives in the same space, where an adaptive optics element (deformable mirror) can compensate aberrations in two views simultaneously, without any switching between them.
Laser excitation beam enters the joined optical path via polychroic mirror M-poly (Fig. 1c). The light sheet is genarated by scanning the galvo mirror M-scan. The same galvo switches the illumination between left and right arm by adding constant bias to the scanning command. This is shown in Fig.2 below.
DM is optimized via stochastic parallel gradient descent (SPGD) algorithm using a PSF quality metric in both views simultaneously. The following example shows how fluorescent bead images (PSFs) in the two views change over iterations.
Full code is available at dm_optmization folder. The total run time of such optimization is 2-3 minutes, limited by the camera frame rate and speed of computations.