Apparatuses for depolarizing light are disclosed. A disclosed passive optical depolarizer for depolarizing a polarized light source includes a waveguide and a first microresonator. The waveguide has a first birefringence. The first microresonator has a second birefringence different from the first birefringence and is evanescently coupled to the waveguide. A disclosed optical amplifier includes a substrate layer, a light source formed over the substrate layer, a waveguide formed over the substrate layer, and a first microresonator formed over the substrate layer. The light source is arranged to emit light from an output. The light has a degree of polarization greater than zero. The waveguide has a first birefringence and an input optically coupled to the output of the light source. The first microresonator has a second birefringence different than the first birefringence and is evanescently coupled to the waveguide.