Fig 1.
a) Color-coded cross section of the final design of the microscope. Not all lenses and apertures are to scale. The red line indicates the imaging light path and the yellow lines indicate the different illumination light paths. b) Photo of the assembled objective/prism unit/camera optics, consisting of parts (1), (2a), (2b), (6) and (7). c) Front part of the microscope. d) Rear part of the microscope when placed inside the scanner.
Fig 2.
Top row: a) Chromatic focal shift of a 9mm diffractive and dispersive achromat and the 8.44mm objective, focal shift of the 8.44 and 15.6mm objectives. (b) Lateral chromatic distortion for three wavelengths. Center row: c) layout and d) ray tracing of the 8.44mm objective, spot diagrams at three field positions, field curvature and field (image) distortion. Bottom: 15.6mm objective. The shaded areas indicate the Airy disk or equivalent axial positions. All simulations are reverse, so the image in the simulation corresponds to the perceived image.
Fig 3.
Top: 50mm (a) and 25mm (b) camera objectives. Bottom (c): Top (left) and bottom (right) bright field illumination channels. The dark field channels differ only by the absence of one prism and a different aperture. The asterisk indicates a hybrid-aspherical surface.
Fig 4.
a) details of the central parts of the 8.44mm objective, b) objective assembly with PMMA sample carrier, c) adapter for a Bruker micro coil, d) Helmholtz micro coil with inserts.
Fig 5.
a) measured and simulated RMS line width. The data in the gray region relates to the 8.44mm objective. b) mean LSF, oversampled by a factor of 5. The grid lines indicate the pixel size. c) MTF in the central FoV and a central axial position. The inset compares the MTF from actual simulated and sampled edge images to the simulated ideal MTF.
Fig 6.
a) Distortion of the magnetic field in a 2mm thick 13mm diameter agarose phantom: Planes through the center of the maximum sample volume (dashed yellow lines), normalized to 0 at the center. Data points without signal inside the sample volume are extrapolated. Worst-case using a RF volume coil enclosing the microscope: b) Magnitude of the MR noise normalized to the average of the background noise (top) without the microscope and with the microscope, without RF and gradient fields, with the gradients turned on and with RF excitation in the presence of a small agarose phantom. Histogram of the magnitude of the MR noise (bottom), normalized such that the integral corresponds to the samples per readout; inset: difference to the background noise. c) Integrated histogram of the optical noise (main graph), histogram of the optical noise (inset) of a black image and a gray image outside of the MR scanner, inside the MR scanner (in the B0 field) and during the MR measurement. Optical sample images (segments of 143 × 121 pixels) and the magnitude of their optical noise scaled by 25.
Fig 7.
Left: MR (a1) and optical (a2) images of polymer beads suspended in water; contrast enhancement (b1), MR color coding (b2) and color addition combinations (b3). Center: MR (c1) and optical (c2) images of the hippocampus of a mouse; contrast enhancement image (c3, blue—optical, black—MR). DG—dentate gyrus, GCL—granule cell layer, SLM—stratum lacunosum-moleculare. Right: MR (d1) and optical (d2, dark field, reconctructed color) images of eremosphaera viridis, (*) likely formation of autospores.