公开(公告)号：US06665075B2

公开(公告)日：2003-12-16

申请号：US10007983

申请日：2001-11-13

申请人： Daniel M. Mittleman ,  Jon L. Johnson

发明人： Daniel M. Mittleman ,  Jon L. Johnson

IPC分类号： G01B902

CPC分类号： G01N21/49

摘要： A broadband imaging system is disclosed that provides greatly enhanced depth resolution through the use of phase shift interferometry. The system may comprise a transmitter, a splitter, a phase inverter, and a receiver. The transmitter transmits a signal pulse that is split into a measurement pulse and a reference pulse. The measurement pulse is applied to a sample, and a relative phase shift of approximately &pgr; radians is introduced between the measurement pulse and the reference pulse by the phase inverter. The measurement and reference pulses are then recombined to form a combined pulse that is detected by the receiver. The phase inverter may be a simple lens that introduces a Gouy phase shift by passing the measurement or reference pulse through a focal point. In this manner, a background-free measurement is provided, which provides a greatly enhanced sensitivity to small changes in the measurement waveform, regardless of origin.