A method to enhance resolution in optical lithography via absorbance-modulation involves exposing an opaque absorbance modulation layer (AML) to a first waveform having wavelength, 81, with the first exposure forming a first set of transparent regions in the opaque AML and forming a first pattern made of a set of exposed regions in a photoresist layer. Next, the AML is restored to its original opaque state. Next, the restored AML is re-exposed to the first waveform having wavelength, 81, with the exposure forming a second set of transparent regions in the opaque AML and forming a second pattern having a set of exposed regions in a photoresist layer. The first and second patterns in the photoresist layer form a final pattern with enhanced resolution and decreased spatial period than the first pattern. In another scenario, instead of exposing the AML to a first waveform, two waveforms are used (the second being complimentary to the first) to ensure that the transmitted image has sharper edges compared to the original image.