An apparatus comprises a multi-clad fiber that includes a light-guiding core surrounded by at least a cladding layer, and an input interface including a first set of input channels in the core configured to receive a first optical fiber, and a second set of input channels in the cladding layer configured to receive a second optical fiber. The apparatus further includes an optical switch module having an input port, a first and a second output port, a first optical path between the input port and the first input channel, and a second optical path between the input port and a second input channel in the second set of input channels. The optical switch module is controllable to switch between the first and the second optical paths. The apparatus also includes a set of laser modules.