1. A method to enhance resolution in optical lithography via absorbance-modulation comprising: a. simultaneously exposing an opaque absorbance modulation layer (AML) to a first waveform having wavelength, 8 1 , and a second waveform having wavelength, 8 2 , the wavelength 8 1 and the wavelength 8 2 are mutually different, said second waveform being a complimentary image of said first waveform, a first exposure forming a first plurality of transparent regions in said opaque AML and a first pattern comprising a plurality of exposed regions in a photoresist layer; b. restoring said AML to original opaque state; c. simultaneously exposing said restored AML to said first waveform having wavelength, 8 1 , and said second waveform having wavelength, 8 2 , a second exposure forming a second plurality of transparent regions in said opaque AML and a second pattern comprising plurality of exposed regions in the photoresist layer, said first and second pattern in said photoresist layer forming a final pattern with enhanced resolution and decreased spatial period than said first pattern; d. iteratively performing steps a-c over multiple exposures using said first and second waveforms; and e. transferring said final pattern from the photoresist layer into a transfer layer, an anti-reflective coating layer, and a substrate by using etching.