Abstract: Methods, systems, and devices are disclosed for implementing Doppler optical coherence tomography and microangiography imaging. In one aspect, a device for optically measuring a sample includes a swept light source to produce an input beam of coherent light for optically probing a target area of a sample, a waveguide to guide the input beam in two independent propagation modes, an optical probe to reflect a first propagation mode back to the waveguide and to direct a second propagation mode to the sample and to overlap the reflection from the sample with the first propagation mode, a differential delay controller to produce variable relative phase delays between the first propagation mode and the second propagation mode, a detection module to combine the first propagation mode and the second propagation mode and to extract information of the sample, and a processing unit to process the information to produce optical images.