A tunable optical transmitter, comprising: a tunable laser comprising a distributed Bragg reflector DBR section, a phase section, and a gain section; and a photodiode detector PD optically coupled to the tunable laser, wherein the tunable optical transmitter lacks a temperature controller, and wherein the tunable optical transmitter is configured to lock onto a wavelength at different operating temperatures; the tunable optical transmitter further comprises: the photodiode detector PD being coupled to the DBR side of the tunable laser and configured to measure an output laser power for a plurality of scanning currents, including a scanning current applied to the DBR section; and a processor coupled to the photodiode detector PD and configured to: determine an output laser power curve of the DBR section based on the scanning current applied to the DBR section, determine from the output laser power curve a first power maximum and a second power maximum that is adjacent to the first power maximum, determine a first DBR section current value associated with the first power maximum and a second DBR section current value associated with the second power maximum, and determine an average of the first DBR section current value and the second DBR section current value as the substantially optimal DBR bias current for a substantially maximal power output for a wavelength. a tunable laser comprising a distributed Bragg reflector DBR section, a phase section, and a gain section; and a photodiode detector PD optically coupled to the tunable laser, wherein the tunable optical transmitter lacks a temperature controller, and wherein the tunable optical transmitter is configured to lock onto a wavelength at different operating temperatures; the tunable optical transmitter further comprises: the photodiode detector PD being coupled to the DBR side of the tunable laser and configured to measure an output laser power for a plurality of scanning currents, including a scanning current applied to the DBR section; and a processor coupled to the photodiode detector PD and configured to: determine an output laser power curve of the DBR section based on the scanning current applied to the DBR section, determine from the output laser power curve a first power maximum and a second power maximum that is adjacent to the first power maximum, determine a first DBR section current value associated with the first power maximum and a second DBR section current value associated with the second power maximum, and determine an average of the first DBR section current value and the second DBR section current value as the substantially optimal DBR bias current for a substantially maximal power output for a wavelength. the photodiode detector PD being coupled to the DBR side of the tunable laser and configured to measure an output laser power for a plurality of scanning currents, including a scanning current applied to the DBR section; and a processor coupled to the photodiode detector PD and configured to: determine an output laser power curve of the DBR section based on the scanning current applied to the DBR section, determine from the output laser power curve a first power maximum and a second power maximum that is adjacent to the first power maximum, determine a first DBR section current value associated with the first power maximum and a second DBR section current value associated with the second power maximum, and determine an average of the first DBR section current value and the second DBR section current value as the substantially optimal DBR bias current for a substantially maximal power output for a wavelength. determine an output laser power curve of the DBR section based on the scanning current applied to the DBR section, determine from the output laser power curve a first power maximum and a second power maximum that is adjacent to the first power maximum, determine a first DBR section current value associated with the first power maximum and a second DBR section current value associated with the second power maximum, and determine an average of the first DBR section current value and the second DBR section current value as the substantially optimal DBR bias current for a substantially maximal power output for a wavelength.