  In this paper, a compact and low-cost structured illumination microscope
(SIM) based on a 2X2 fiber coupler is presented. Fringe illumination is
achieved by placing two output fiber tips at a conjugate Fourier plane of the
sample plane as the point sources. Raw structured illumination (SI) images in
different pattern orientations are captured when rotating the fiber mount.
Following this, high resolution images are reconstructed from no-phase-shift
raw SI images by using a joint Richardson-Lucy (jRL) deconvolution algorithm.
Compared with an SLM-based SIM system, our method provides a much shorter
illumination path, high power efficiency, and low cost.
