  Information multiplexing is important for biomedical imaging and chemical
sensing. In this paper, we report a microscopy imaging technique, termed
state-multiplexed Fourier ptychography (FP), for information multiplexing and
coherent-state decomposition. Similar to a typical Fourier ptychographic
setting, we use an array of light sources to illuminate the sample from
different incident angles and acquire corresponding low-resolution images using
a monochromatic camera. In the reported technique, however, multiple light
sources are lit up simultaneously for information multiplexing, and the
acquired images thus represent incoherent summations of the sample transmission
profiles corresponding to different coherent states. We show that, by using the
state-multiplexed FP recovery routine, we can decompose the incoherent mixture
of the FP acquisitions to recover a high-resolution sample image. We also show
that, color-multiplexed imaging can be performed by simultaneously turning on
R/G/B LEDs for data acquisition. The reported technique may provide a solution
for handling the partially coherent effect of light sources used in Fourier
ptychographic imaging platforms. It can also be used to replace spectral
filter, gratings or other optical components for spectral multiplexing and
demultiplexing. With the availability of cost-effective broadband LEDs, the
reported technique may open up exciting opportunities for computational
multispectral imaging.
