Appl. Phys. Lett. 114, 161901 (2019)

Most methods for complex wavefront reconstruction require arrayed sensors to detect the light pattern. Now, Ruifeng Liu and colleagues at Xi’an Jiaotong University in China have demonstrated detection and reconstruction of a field of unknown amplitude and phase using a single-pixel detector. The team exploited a checkerboard pattern on a digital micromirror device (DMD) to sample the unknown complex amplitude field, using a single-beam approach that they say is compact and stable. The beam to be analysed and reconstructed originated from a He–Ne laser (632.8 nm) and was sent to a phase spatial light modulator (SLM) and spatially encoded so that it had a complex wavefront. To perform the reconstruction, the beam was imaged onto a DMD and a pinhole was used to block undesired diffraction orders from the SLM. Another pinhole and a single photodiode were used to detect the intensity in the central position of the interference pattern. The demonstration was done with up to 128 × 128 discretized pixels (each with area of about 55 × 55 μm2) and real-time wavefront reconstruction was achieved at a rate of 6 Hz (for 32 × 32 pixels).

Credit: AIP Publishing