Chip-based wide field-of-view total internal reflection fluorescence microscopy

Conventional total internal reflection fluorescence (TIRF) microscopy requires either an oil-immersed objective with high numerical aperture or a bulky prism with high refractive index to generate the evanescent waves that work as the illumination source for fluorophores. Precise alignment of the optical path is necessary for optimizing the imaging performance of TIRF microscopy, which increases the operation complexity. In this Letter, a planar photonic chip composed of a dielectric multilayer and a scattering layer is proposed to replace the TIRF objective or the prism. The uniform evanescent waves can be excited under uncollimated incidence through this chip, which simplifies the alignment of the optical configurations and provides shadowless illumination. Due to the separation of the illumination and detection light paths, TIRF microscopy can have a large field-of-view (FOV).