Abstract: Consistent with the present disclosure, one or more spare Widely Tunable Lasers (WTLs) are integrated on a PIC. In the event that a channel, including, for example, a laser, a modulator and a semiconductor optical amplifier in a transmitter or Tx PIC, or a laser, optical hybrid, and photodiodes, for example, in a receiver PIC (Rx PIC), includes one or more defective devices, a spare channel is selected that includes a widely tunable laser (WTL) which may be tuned to the wavelength associated with any of the channels on the PIC. Accordingly, the spare channel replaces the defective channel or the lowest performing channel and outputs modulated optical signals at the wavelength associated with the defective channel. Thus, even though a defective channel may be present, a die consistent with the present disclosure may still output or receive the desired channels because the spare channel replaces the defective channel.