Digital holography with a cell-phone camera module

Since digital holography was first developed in the early 1990s, camera pixel pitch has decreased considerably. In particular, image sensors targeting the mobile phone market now feature very small pixels with high pixel count. These image sensors, though inexpensive, can be used in digital holography, taking advantage of their fine pixel pitch. This paper describes the use of the Raspberry Pi NoIR camera for pulsed digital holography and its applications in imaging biological samples and compressible flows. It addresses the challenges of generating pulsed holograms using color cameras with rolling shutters. We show that, in order to prevent artifacts at high resolution, color calibration must be performed. Single-pulse frames can be collected with a rolling shutter if the frame integration time can be increased to the frame readout time and the laser firing can be synchronized to frame exposure.