  We present a microscope paradigm that performs differential interference
imaging with high sensitivity via optical amplification and radio-frequency
(RF) heterodyne detection. This method, termed differentially-enhanced sideband
imaging via radio-frequency encoding (DESIRE), uniquely exploits
frequency-to-space mapping technique to encode the image of an object onto the
RF sidebands of an illumination beam. As a proof-of-concept, we show validation
experiment by implementing radio frequency (f = 15 GHz) phase modulation in
conjunction with spectrally-encoded laser scanning technique to acquire
one-dimensional image of a barcode-like object using a commercial RF spectrum
analyzer.
