Extended Data Fig. 1: Instrument overview.
a) Photograph of instrument, highlighting objectives, cameras, sample area. b) CAD rendering of MEMS line scanner. c) Optical set-up. Diode lasers are combined and passed through an acousto-optic tunable filter (AOTF) for shuttering and power control, before being directed into broadband single-mode fibres. Galvanometric mirrors are used to direct beams into each fibre, and to adjust the power of the beams entering the fibre. Each fibre is then fed into a MEMS line scanner (purple dot-dashed line, here only one shown for clarity), with optics as indicated. The scanner serves to collimate the fibre output, focus it with a cylindrical lens, scan it with a MEMS mirror, and image the scanned output to a field stop at a conjugate sample plane. The beam is then relayed via lens L3 and the objective to the sample plane, after reflection from a dichroic mirror. Fluorescence is collected in epi-mode, transmitted through a dichroic mirror, and imaged via tube lens L4 onto a scientific CMOS camera where it is synchronized to the rolling shutter readout. d) Control waveforms issued to camera, MEMS scanner, objective piezo, and AOTF, used to acquire volumetric data. See also Supplementary Methods. e) Example line illumination at various lateral positions on camera chip, as imaged with fluorescent dye in lower view C. Excitation PSF measurements are taken at various positions in the field (see also Extended Data Fig. 2a, c). Scale bar: 50 μm. f) Example images acquired in C. elegans embryo expressing GFP-histones, as visualized in bottom view C with widefield mode (top) and line-scanning mode (slit width 0.58 μm, bottom). Scale bar: 5 μm.
