Real-time SPR imaging based on a large area beam from a wavelength-swept laser

We demonstrate a real-time surface plasmon resonance imaging (SPRi) system based on a wavelength-swept laser. Compared to conventional spectral-modulation SPRi using white light source and spectral filtering, the proposed system has a higher scan rate to detect rapid changes in refractive index and a higher output power for large-area illumination. This SPRi system achieves scan rates faster than 12 Hz, simultaneously obtaining SPR dip positions over full illumination fields of 12×12  mm. Using the wavelength-swept laser, two-dimensional biomolecular array imaging can be acquired with a high dynamic detection range (7.67×10−3 refractive index unit (RIU)) as well as high sensitivity (6501 nm/RIU) and resolution (1.89×10−6  RIU).