Patent ID: 7365858

Claim:
A method for imaging a sample comprising the steps of: illuminating a sample, the light originating from a point on the sample having a low frequency spatial component and high frequency spatial components; interfering along a common optical path the high frequency spatial components with the low frequency spatial component to produce a first intensity signal; shifting the phase of the low frequency spatial component to produce a first phase shifted low frequency spatial component; interfering along a common optical path the high frequency spatial components with the first phase shifted low frequency spatial component to produce a second intensity signal; shifting the phase of the low frequency spatial component to produce a second phase shifted low frequency spatial component; interfering along a common optical path the high frequency spatial components with the second phase shifted low frequency spatial component to produce a third intensity signal; shifting the phase of the low frequency spatial component to produce a third phase shifted low frequency spatial component; interfering along a common optical path the high frequency spatial components with the third phase shifted low frequency spatial component to produce a fourth intensity signal; generating a phase image of the point on the sample based at least in part on the first intensity signal, the second intensity signal, the third intensity signal and the fourth intensity signal.