An optical power supply comprising: • a plurality of lasers (202a, 202b, 202c, 202d) each configured to provide an output at a respective optical wavelength and optical power; • a plurality of optical splitter groups (204a, 204b, 204c, 204d), each comprising an input associated with a respective one of the plurality of lasers (202a, 202b, 202c, 202d) and configured to split the input into a plurality of outputs each having an output power approximated by: Power n = 1 x n Power input, where: x is an integer greater than 1; n is a number of the outputs of the optical splitter group and n = 1.. m; m is a total number of outputs of the optical splitter group; Power n is the output power of the n th output; and Power input is the optical power of the output of the laser received at the input of the optical splitter group; • a plurality of optical modulator groups (206a, 206b, 206c, 206d) each comprising a plurality of modulator inputs and associated modulator outputs, each of the plurality of modulator inputs of a respective optical modulator group connected to a respective output from different optical splitting groups such that, for each modulator group, a data bit data i is configured to modulate an optical input having the ( w - i) th highest optical power of the optical modulator group, where data i is the i th bit in a data signal and i = 0.. w - 1, where data w -1 is the most significant bit; and w is the number of bits in the data signal. • a plurality of lasers (202a, 202b, 202c, 202d) each configured to provide an output at a respective optical wavelength and optical power; • a plurality of optical splitter groups (204a, 204b, 204c, 204d), each comprising an input associated with a respective one of the plurality of lasers (202a, 202b, 202c, 202d) and configured to split the input into a plurality of outputs each having an output power approximated by: Power n = 1 x n Power input, where: x is an integer greater than 1; n is a number of the outputs of the optical splitter group and n = 1.. m; m is a total number of outputs of the optical splitter group; Power n is the output power of the n th output; and Power input is the optical power of the output of the laser received at the input of the optical splitter group; x is an integer greater than 1; n is a number of the outputs of the optical splitter group and n = 1.. m; m is a total number of outputs of the optical splitter group; Power n is the output power of the n th output; and Power input is the optical power of the output of the laser received at the input of the optical splitter group; • a plurality of optical modulator groups (206a, 206b, 206c, 206d) each comprising a plurality of modulator inputs and associated modulator outputs, each of the plurality of modulator inputs of a respective optical modulator group connected to a respective output from different optical splitting groups such that, for each modulator group, a data bit data i is configured to modulate an optical input having the ( w - i) th highest optical power of the optical modulator group, where data i is the i th bit in a data signal and i = 0.. w - 1, where data w -1 is the most significant bit; and w is the number of bits in the data signal.