Spectral multiplexing and coherent-state decomposition in Fourier ptychographic imaging

Abstract

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 statemultiplexed 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. References and links1. G. Zheng, R. Horstmeyer, and C. Yang, "Wide-field, high-resolution Fourier ptychographic microscopy," Nat.Photonics 7(9), 739-745 (2013). 2. M. Ryle and A. Hewish, "The synthesis of large radio telescopes," Mon. Not. R. Astron. Soc. 120, 220 (1960). 3. A. B. Meinel, "Aperture synthesis using independent telescopes," Appl. Opt. 9(11), 2501 (1970). 4. R. Gerchberg, "A practical algorithm for the determination of phase from image and diffraction plane pictures," Optik (Stuttg.) 35, 237 (1972). 5. J. R. Fienup, "Reconstruction of an object from the modulus of its Fourier transform," Opt. Lett. 3(1), 27-29 (1978). 6. L. Taylor, "The phase retrieval problem," IEEE Trans. Antennas Propag. 29(2), 386-391 (1981). 7. J. R. Fienup, "Phase retrieval algorithms: a comparison," Appl. Opt. 21(15), 2758-2769 (1982). 8. R. A. Gonsalves, "Phase retrieval and diversity in adaptive optics," Opt. Eng. 21, 215829 (1982). 9. R. A. Gonsalves, "Phase retrieval by differential intensity measurements," J. Opt. Soc. Am. A. 4(1), 166-170 (1987). 10. L. Allen and M. Oxley, "Phase retrieval from series of images obtained by defocus variation," Opt. Commun.199 ( Ther. 5(8), 1033-1038 (2006). 41. K. Hoshino, P. P. Joshi, G. Bhave, K. V. Sokolov, and X. Zhang, "Use of colloidal quantum dots as a digitally switched swept light source for gold nanoparticle based hyperspectral microscopy," Biomed.

Aperture-scanning Fourier ptychography for 3D refocusing and super-resolution macroscopic imaging

“…We note that this basic recovery process assumes the illumination field extending across the sample's lateral extent is coherent. A more advanced FP recovery procedure may incorporate partial coherence modeling [3]. The recovery algorithm starts with a high-resolution spectrum estimate of the sample, 0 ( U x y k , k ) .…”

“…A deconvolution operation can recover the same data that a fully coherent FP setup would capture, assuming the source shape A is known and that noise is negligible. Finally, we note that, a mixed-state formulation can be used to model the partially coherent effects in FP platforms [3]. The finite extent of the light source can be modeled as multiple independent point sources.…”

“…Fourier ptychography (FP) is a phase retrieval technique that uses the concept of angular diversity to recover high-resolution complex sample images [1][2][3]. Similar to other phase retrieval techniques [4][5][6][7][8][9][10][11][12][13][14], the recovery process of FP consists of alternating enforcement of the known sample information in the spatial domain, and a fixed constraint in the Fourier domain.…”

“…These images are then iteratively stitched together in the Fourier domain to recover a high-resolution, complex sample image. Prior work has demonstrated FP's microscopic imaging capabilities well beyond the cutoff frequency defined by the objective lens [1], its acquisition of quantitative phase [2], and the spectral multiplexing capability [3]. Recent reviews on the FP approach can be found in [28,29].…”

Self-learning based Fourier ptychographic microscopy

“…Tian et al [3] demonstrated that it is possible to turn on several LEDs at once during the image collection procedure, showing data reduction from 293 to 40 images, along with a reduction of acquisition time of up to 90%, without significant loss of image fidelity. Multiplexing can also be used for the RGB spectral channels, as shown by Dong et al [12]. These variations on FPM have found applications in quantitative phase imaging [13], gigapixel microscopy [14], high-resolution fluorescence imaging [15] and more [16][17][18].…”