US 6,665,075 B2 · Interferometric imaging system and method

Abstract

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 π 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.

Claims24

Dependent claims

A measurement apparatus that comprises:

a transmitter that provides a transmitted signal pulse;
a beam splitter that splits the transmitted signal pulse into a measurement pulse and a reference pulse, wherein the measurement pulse interacts with a sample before being re-combined with the reference pulse to form a combined pulse;
a phase inverter that provides a relative phase shift between the measurement and reference pulses of approximately π radians across most frequency components of the transmitted pulse;
and
a receiver that receives the combined pulse.

2 more elements

Dependencies are inferred from the claim text.

Interferometric imaging system and method

Life of this patent

Interferometric imaging system and method

Life of this patent

Abstract

Claims24