Structured illumination microscopy using digital micromirror device and coherent light source

Structured illumination microscopy (SIM) achieves doubled spatial resolution through exciting the specimen with high-contrast, high-frequency sinusoidal patterns. Such an illumination pattern can be generated by laser interference or incoherent structured pattern. Opto-electronic devices, such as Spatial Light Modulator (SLM) or Digital Micro-mirror Device (DMD), can provide rapid switch of illumination patterns for SIM. Although DMD is much more cost-effective than SLM, it was previously restricted in association with incoherent light sources. To extend its application with coherent illumination, we model the DMD as a blazed grating, and simulate the effect with DMD pattern changes in SIM. Based on the simulation, we report a fast, high-resolution and cost-efficient SIM with DMD. Our home-built laser interference-based DMD-SIM (LiDMD-SIM) reveals the nuclear pore complex and microtubule in mammalian cells with doubled spatial resolution.