An optical apparatus (200, 250, 260, 270, 300, 360, 370, 380) comprising: a silicon semiconductor substrate (202, 302); a silicon-germanium absorption layer (206, 306) coupled to the silicon semiconductor substrate, the absorption layer including an optical sensor region configured to absorb photons and to generate photo-carriers from the absorbed photons; one or more first switches (208, 210, 308, 310) controlled by a first control signal (222, 232, 322, 332), the one or more first switches configured to collect at least a portion of the photo-carriers based on the first control signal; and one or more second switches (208, 210, 308, 310) controlled by a second control signal (222, 232, 322, 332), the one or more second switches configured to collect at least a portion of the photo-carriers based on the second control signal, wherein the second control signal is different from the first control signal, wherein the one or more first switches comprise: a first p-doped region (228, 238, 328, 338) in the silicon semiconductor substrate, wherein the first p-doped region is controlled by the first control signal; and a first n-doped region (226, 236, 326, 336) in the silicon semiconductor substrate, wherein the first n-doped region is coupled to a first readout integrated circuit, and wherein the one or more second switches comprise: a second p-doped region (228, 238, 328, 338) in the silicon semiconductor substrate, wherein the second p-doped region is controlled by the second control signal; and a second n-doped region (226, 236, 326, 336) in the silicon semiconductor substrate, wherein the second n-doped region is coupled to a second readout integrated circuit. a silicon semiconductor substrate (202, 302); a silicon-germanium absorption layer (206, 306) coupled to the silicon semiconductor substrate, the absorption layer including an optical sensor region configured to absorb photons and to generate photo-carriers from the absorbed photons; one or more first switches (208, 210, 308, 310) controlled by a first control signal (222, 232, 322, 332), the one or more first switches configured to collect at least a portion of the photo-carriers based on the first control signal; and one or more second switches (208, 210, 308, 310) controlled by a second control signal (222, 232, 322, 332), the one or more second switches configured to collect at least a portion of the photo-carriers based on the second control signal, wherein the second control signal is different from the first control signal, wherein the one or more first switches comprise: a first p-doped region (228, 238, 328, 338) in the silicon semiconductor substrate, wherein the first p-doped region is controlled by the first control signal; and a first n-doped region (226, 236, 326, 336) in the silicon semiconductor substrate, wherein the first n-doped region is coupled to a first readout integrated circuit, and a first p-doped region (228, 238, 328, 338) in the silicon semiconductor substrate, wherein the first p-doped region is controlled by the first control signal; and a first n-doped region (226, 236, 326, 336) in the silicon semiconductor substrate, wherein the first n-doped region is coupled to a first readout integrated circuit, and wherein the one or more second switches comprise: a second p-doped region (228, 238, 328, 338) in the silicon semiconductor substrate, wherein the second p-doped region is controlled by the second control signal; and a second n-doped region (226, 236, 326, 336) in the silicon semiconductor substrate, wherein the second n-doped region is coupled to a second readout integrated circuit. a second p-doped region (228, 238, 328, 338) in the silicon semiconductor substrate, wherein the second p-doped region is controlled by the second control signal; and a second n-doped region (226, 236, 326, 336) in the silicon semiconductor substrate, wherein the second n-doped region is coupled to a second readout integrated circuit.