A quantum well modulator configured to absorb or transmit light depending on an applied voltage is provided according to various embodiments. The quantum well modulator may include a substrate, a p-type and n-type semiconductor layers as well as a quantum well layer, each of which are deposited above the substrate. The substrate may be configured to filter light incident thereon, wherein the substrate does not include a reflective surface. The flip-chip quantum well modulator may be configured to substantially absorb light received through the substrate when a first voltage is applied. The flip-chip quantum well modulator may be configured to substantially transmit light received through the substrate when a second voltage is applied.