Patent ID: 8831439

Claim:
An apparatus, comprising: a digital signal processor circuit configured to receive input data, and spectrally shape the input data to supply spectrally shaped data as a first plurality of data samples at a first data rate; an interpolation circuit that receives the first plurality of data samples at the first sampling rate and outputs the spectrally shaped data as a second plurality of data samples at a second data rate greater than the first sampling rate, the interpolation circuit including: a filter circuit configured to receive the spectrally shaped data, the filter circuit supplying a third plurality of samples at the first data rate, and a memory configured to receive the third plurality of samples at the first data rate and supply the second plurality of samples at the second data rate, such that a number of the third plurality of samples input to the memory over a time period being equal to a number of the second plurality of samples output from the memory over the time period, a digital-to-analog converter circuit configured to receive the second plurality of data samples and generate an analog signal; a modulator circuit; and a laser configured to supply light to the modulator circuit, the modulator circuit being configured to modulate the light to supply a modulated optical signal in response to the analog signal.