title: Digital micromirror device-based laser-illumination Fourier ptychographic microscopy.
abstract: We report a novel approach to Fourier ptychographic microscopy (FPM) by using a digital micromirror device (DMD) and a coherent laser source (532 nm) for generating spatially modulated sample illumination. Previously demonstrated FPM systems are all based on partially-coherent illumination, which offers limited throughput due to insufficient brightness. Our FPM employs a high power coherent laser source to enable shot-noise limited high-speed imaging. For the first time, a digital micromirror device (DMD), imaged onto the back focal plane of the illumination objective, is used to generate spatially modulated sample illumination field for ptychography. By coding the on/off states of the micromirrors, the illumination plane wave angle can be varied at speeds more than 4 kHz. A set of intensity images, resulting from different oblique illuminations, are used to numerically reconstruct one high-resolution image without obvious laser speckle. Experiments were conducted using a USAF resolution target and a fiber sample, demonstrating high-resolution imaging capability of our system. We envision that our approach, if combined with a coded-aperture compressive-sensing algorithm, will further improve the imaging speed in DMD-based FPM systems.
authors.forename: Cuifang
authors.initials: C
authors.lastname: Kuang
authors.forename: Ye
authors.initials: Y
authors.lastname: Ma
authors.forename: Renjie
authors.initials: R
authors.lastname: Zhou
authors.forename: Justin
authors.initials: J
authors.lastname: Lee
authors.forename: George
authors.initials: G
authors.lastname: Barbastathis
authors.forename: Ramachandra R
authors.initials: RR
authors.lastname: Dasari
authors.forename: Zahid
authors.initials: Z
authors.lastname: Yaqoob
authors.forename: Peter T C
authors.initials: PT
authors.lastname: So
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D005583:Fourier Analysis; D007089:Image Enhancement / Q000295:instrumentation*; D007834:Lasers; D007909:Lenses; D008029:Lighting / Q000295:instrumentation*; D008853:Microscopy / Q000295:instrumentation*; D008904:Miniaturization; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*