An example device includes a first semiconductor component comprising at least two lasers to emit light at a first wavelength; a second semiconductor component comprising at least two lasers to emit light at a second wavelength, the first wavelength being different from the second wavelength; and an optical multiplexer to receive light from two lasers at the first wavelength and light from two lasers at the second wavelength. The optical multiplexer component includes a first output interface to couple light from one laser at the first wavelength and light from one laser at the second wavelength to a first optical fiber, and a second output interface to couple light from one laser at the first wavelength and light from one laser at the second wavelength beams to a second optical fiber.