The invention relates to an optical coherence tomography data collection apparatus. The apparatus can include a sample clock generator, where the sample clock generator can be configured to clock an analog-to-digital converter. The analog-to-digital converter can be configured to sample interference signals at an output of a main interferometer. The sample clock generator comprises an interferometer having an input and an output, the interferometer being in electrical or optical communication with the laser and configured to receive the laser light, a balanced photoreceiver having an input in optical or electrical communication with the output of the interferometer, the photoreceiver having an output, a frequency multiplier having an input in optical or electrical communication with the output of the photoreceiver, the frequency multiplier having an output and a zero-cross detector having an input in optical or electrical communication with the output of the frequency multiplier, the output of the zero-crossing detector being the generated clock.
METHODS AND APPARATUS FOR SWEPT-SOURCE OPTICAL COHERENCE TOMOGRAPHY