Cascaded optical modulation system
AssigneeNorthrop Grumman Systems Corporation
InventorsSteven M. Kim, Daniel A. Tazartes, Gregory A. Zimmerman, Leonard A. Atkinson
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Abstract
One example includes an optical system. The system includes a laser configured to generate an optical beam and an optical modulation system comprising a plurality of optical modulators arranged in a cascaded sequence. Each of the optical modulators can be configured to provide successive modulation of the optical beam in the cascaded sequence to provide a modulated optical beam. The system further includes an optical assembly configured to receive the modulated optical beam and to implement the modulated optical beam for an optical functional application.
Claims19
An optical system comprising:
- a laser configured to generate an optical beam;
- an optical modulation system comprising a plurality of optical modulators arranged in a cascaded sequence, each of the optical modulators being configured to provide successive modulation of the optical beam in the cascaded sequence to provide a modulated optical beam by providing an approximately equal amount of phase-shift to a same phase of the optical beam in succession in the cascaded sequence;
- and
- an optical assembly configured to receive the modulated optical beam and to implement the modulated optical beam for an optical functional application.
A method for determining rotation about a sensitive axis for a fiber-optic gyroscope (FOG) system, the method comprising:
- generating an optical beam via a laser;
- successively modulating the optical beam via a plurality of optical modulators arranged in a cascaded sequence along an optical path of the optical beam to generate a modulated optical beam by providing an approximately equal amount of phase-shift to a same phase of the optical beam in succession in the cascaded sequence;
- splitting the modulated optical beam into a first modulated optical beam and a second modulated optical beam;
- providing the first modulated optical beam to a first port of an optical fiber coil comprising an optical fiber counter-wound in opposite orientations;
- providing the second modulated optical beam to a second port of the optical fiber coil, the first and second ports corresponding to respective opposite ends of the optical fiber;
- monitoring a relative phase between the first modulated optical beam being provided from the second port of the optical fiber coil and the second modulated optical beam being provided from the first port of the optical fiber coil;
- and
- measuring rotation of the FOG about the sensitive axis based on the relative phase between the first and second modulated optical beams.
A fiber-optic gyroscope (FOG) system comprising:
- a laser configured to generate an optical beam;
- an optical modulation system comprising:
- a modulation controller configured to generate a digital Gaussian noise signal and to condition the digital Gaussian noise signal in each of a plurality of digital modulation paths to provide a respective plurality of digital modulation signals;
- and
- a plurality of optical modulators arranged in a cascaded sequence, each of the optical modulators being configured to provide successive modulation of the optical beam in the cascaded sequence to provide a modulated optical beam by providing an approximately equal amount of phase shift to a same phase of the optical beam in succession in the cascaded sequence;
- and
- a FOG assembly comprising an optical fiber coil, the FOG assembly being configured to measure rotation about a sensitive axis associated with the optical fiber coil based on a relative phase difference of the modulated optical beam propagating in each of opposite directions through the optical fiber coil.
Dependencies are inferred from the claim text.