Back to results
US 8,134,715 B2Granted
Adjustable interferometer for laser ultrasonic measurement
AssigneeiPhoton Solutions, LLC
InventorsThomas E. Drake, Marc Dubois
Life of this patent
Estimating the term…
Abstract
An interferometer includes a cavity including a pair of mirrors defining a cavity length. An input beam and a counter-propagating reference beam are directed into the cavity. The interferometer generates a feedback control signal and an ultrasound signal for optimal performance and measurement of a target, respectively.
Claims37
An interferometer, comprising:
- a first cavity including a pair of mirrors, at least one of which being movable, defining a first cavity length;
- a second cavity including a pair of mirrors, at least one of which being movable, defining a second cavity length;
- a first beam splitter for directing a first polarized input beam into the first cavity through a first phase shift element;
- a second beam splitter for directing a first polarized reference beam into the first cavity through a second phase shift element;
- a third beam splitter for directing a second polarized input beam into the second cavity through a third phase shift element;
- a fourth beam splitter for directing a second polarized reference beam into the second cavity through a fourth phase shift element;
- a first optical detector for receiving from the first beam splitter a first and a second output beam, the first and second output beams being generated responsive to the respective first polarized input beam and the first polarized reference beam, the first optical detector generating a first signal responsive to the first output beam and to the second output beam;
- a second optical detector for receiving from the second beam splitter a third and a fourth output beam, the third and fourth output beams being generated responsive to the respective first polarized input beam and the first polarized reference beam, the second optical detector generating a second signal responsive to the third output beam and the fourth output beam;
- a third optical detector for receiving from the third beam splitter a fifth and a sixth output beam, the fifth and sixth output beams being generated responsive to the respective second polarized input beam and the second polarized reference beam, the third optical detector generating a third signal responsive to the fifth output beam and to the sixth output beam;
- a fourth optical detector for receiving from the fourth beam splitter a seventh and an eighth output beam, the seventh and eighth output beams being generated responsive to the respective second polarized input beam and the second polarized reference beam, the fourth optical detector generating a fourth signal responsive to the seventh output beam and to the eighth output beam;
- a first feedback control system for receiving the first and second signals and in response to at least one of the first and second signals generating a first feedback control signal for adjusting the first cavity length;
- and
- a second feedback control system for receiving the third and fourth signals and in response to at least one of the third and fourth signals generating a second feedback control signal for adjusting the second cavity length.
10 more elements
An interferometer, comprising:
- a cavity including a pair of mirrors defining a cavity length;
- a first beam splitter for directing an input beam into the cavity through a first phase shift element;
- a second beam splitter for directing a reference beam into the cavity through a second phase shift element;
- a first optical detector for receiving from the first beam splitter a first and a second output beam, the first and the second output beam being generated responsive to the respective input beam and the reference beam, the first optical detector generating a first signal responsive to the first output beam and to the second output beam;
- a second optical detector for receiving from the second beam splitter a third and a fourth output beam, the third and the fourth output beam being generated responsive to the respective input beam and the reference beam, the second optical detector generating a second signal responsive to the third output beam and to the fourth output beam;
- and
- a feedback control system for receiving the first and second signals and in response to at least one of the first and second signals generating a feedback control signal for adjusting the cavity length.
4 more elements
A method for adjusting a cavity length of an interferometer having at least one movable mirror, comprising:
- generating a reference beam and a primary beam;
- directing the primary beam onto a target;
- accumulating scattered beam from the target and generating an input beam responsive to the scattered beam;
- directing the input beam and the reference beam into the interferometer through different beam splitters;
- generating a first output beam responsive to the input beam and a second output beam responsive to the reference beam;
- generating a control signal responsive to the second output beam and an ultrasound signal responsive to the first output beam;
- and
- adjusting the cavity length of the interferometer responsive to the control signal.
5 more elements
A method for adjusting the frequency of a source beam relative to an interferometer cavity, comprising:
- generating a reference beam and a primary beam derived from the source beam;
- directing the primary beam onto a target;
- accumulating scattered beam from the target and generating an input beam responsive to the scattered beam;
- directing the input beam and the reference beam into the interferometer cavity through different polarizing beam splitters;
- generating a first output beam responsive to the input beam and a second output beam responsive to the reference beam;
- generating a control signal responsive to the second output beam;
- and
- adjusting the frequency of the source beam responsive to the control signal.
5 more elements
Dependencies are inferred from the claim text.