The optical assembly for modulating input light and providing modulated light at an output thereof includes a first arrangement, which includes a layer of a superconductive material having at least a part of the input light incident thereon as incident light. The superconductive material is switchable between a first state, in which the superconductive material exhibits a first refractive index, and a second state, in which the superconductive material exhibits a second refractive index. The first arrangement is configured to direct to the output as the modulated light a first fraction of the incident light, when the superconductive material is in the first state, and a second fraction of the incident light, when the superconductive material is in the second state, such that the modulated light exhibits a given value of extinction ratio, which is defined as a ratio of the first fraction of the incident light to the second fraction of the incident light at the output. The optical assembly further includes a second arrangement cooperating with the first arrangement to provide at the output of the optical assembly another value of the extinction ratio that is smaller than the given value.