  Dual-comb microscopy (DCM), based on a combination of dual-comb spectroscopy
(DCS) with two-dimensional spectral encoding (2D-SE), is a promising method for
scan-less confocal laser microscopy giving an amplitude and phase image
contrast with the confocality. However, signal loss in a 2D-SE optical system
hampers increase in image acquisition rate due to decreased signa-to-noise
ratio. In this article, we demonstrated optical image amplification in DCM with
an erbium-doped fiber amplifier (EDFA). Combined use of image-encoded DCS
interferogram and EDFA benefits from not only the batch amplification of
amplitude and phase images but also significant rejection of amplified
spontaneous emission (ASE) background. Effectiveness of the
optical-image-amplified DCM is highlighted in the single-shot quantitative
nanometer-order surface topography and the real-time movie of polystyrene beads
dynamics under water convection. The proposed method will be a powerful tool
for real-time observation of surface topography and fast dynamic phenomena.
