Single-pixel optical edge imaging with an extended depth-of-field.

In this Letter, we report a single-pixel imaging (SPI) method for optical edge detection with an extended depth-of-field (DOF). To realize enhanced DOF in optical imaging, our method exploits a sequence of propagation-invariant sinusoidal fringes (PISFs) to illuminate the object. Furthermore, the spiral phase is encoded into the sinusoidal fringes in k-space to acquire the Fourier spectrum of the edge-enhanced image. Experimentally, the phase-encoded PISFs are generated and scanned by a digital micromirror device (DMD). A single-pixel detector synchronously measures the total intensity of the signal light in sequence for image reconstruction. Our method achieves a DOF of 3800 μm for NA = 0.1, achieving a 60-fold improvement over the conventional counterpart. The superior performance is demonstrated by imaging the USAF resolution target and living algal cells.