Phase-contrast serial time-encoded amplified microscopy

In this paper, the authors demonstrate a new type of imaging modality that enables ultrafast image acquisition based on spectral interferometry and amplified dispersive Fourier transformation. The approach is based on serial time- encoded amplified microscopy (STEAM) that was previously demonstrated for ID ultrafast (world record) barcode reading and displacement sensing. The new implementation reported here is the interferometric version of STEAM and performs both axial and transverse imaging. This is achieved by first encoding the 2D image matrix into a 1D vector consisting of the spectrum of a broadband pulse using a low coherence interferometer.The spectrum (and hence the image) is then optically amplified and mapped into time using a Raman pumped dispersive fiber. The serialized and amplified image is then detected using a single-pixel detector and digitized using a real-time digitizer/oscilloscope. The image is reconstructed in the digital domain by converting the serial ID vector into the original 2D matrix. The optical amplification in the dispersive fiber overcomes the trade-off between sensitivity and frame rate, and the time domain detection using an oscilloscope eliminates the CCD or CMOS camera and the associated speed limitations.