In part, the invention relates to methods, devices, and systems suitable for controlling a light source. The light source is configured for use in a data collection system such as an optical coherence tomography system. The light source can be controlled with a drive waveform. Linearizing and symmetrizing parameters of the light source such as forward and backward scan durations is achieved using a suitable drive waveform. Phase, amplitude, and other parameters for different harmonics of a fundamental wave can be identified that improve operating parameters such as the duty cycle and peak frequency matching between scans. The fundamental wave and one or more of such harmonics can be combined to generate the suitable drive wave form. The light source can include a tunable light source that includes or is in optical communication with a tunable filter.