RFOG with reduced polarization mode induced bias error
AssigneeHoneywell International Inc.
InventorsTiequn Qiu, Glen A Sanders, Lee Strandjord
Life of this patent
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Abstract
Hollow core fiber RFOG having symmetric M-(or W-)shape, three-(or two-)mirror configurations. These symmetric configurations help to cancel out polarization error induced bias of the RFOG even when light of the unwanted ESOP is present. The RFOG resonator with optical components forming substantially small cross-coupling angles between their polarization axes, and/or with polarizing elements inserted into the resonator, and/or with resonator mirrors having identical reflectivity for light of different polarization states, can effectively reduce the polarization mode induced bias error.
Claims20
An optical gyro comprising:
- a ring resonator configured to circulate light beams in counter-propagating directions, the ring resonator comprising an optical fiber coil having first and second ends;
- first and second optical elements configured to
- receive two input light beams;
- and
- transmit a majority of the two input light beams in counter-propagating directions in the ring resonator, the majority of each input light beams entering one of the first and second ends of the optical fiber coil;
- and
- a third optical element configured to
- direct a majority of the circulating light beams in the counter-propagating directions of the ring resonator via the first and second optical elements;
- and
- derive a transmission component of the circulating light beams, the transmission component impinging on a photodetector for each of the counter-propagating beams.
An optical gyro comprising:
- a ring resonator configured to circulate light beams in counter-propagating directions, the ring resonator comprising an optical fiber coil having first and second ends;
- a first optical element configured to
- receive two input light beams;
- and
- transmit a majority of the two input light beams in counter-propagating directions in the ring resonator, the majority of the input light beams entering one of the first and second ends of the optical fiber coil;
- and
- a second optical element configured to
- direct a majority of the circulating light beams in the counter-propagating directions of the ring resonator via the first and second optical elements;
- and
- derive a transmission component of the circulating light beams, the transmission component impinging on a photodetector for each of the counter-propagating beams.
A method comprising:
- receiving two input light beams at least one first optical element;
- transmitting a majority of the two input light beams in counter-propagating directions in a ring resonator having optical fiber coil having first and second ends, the majority of the input light beams entering one of the first and second ends of the optical fiber coil;
- receiving the counter-propagating light beams from the first and second ends of the optical fiber coil;
- directing the received counter-propagating light beams to a second optical element;
- at the second optical element
- directing a majority of the directed counter-propagating light beams to the optical fiber coil via the at least one first optical element;
- and
- directing a portion of the directed counter-propagating light beams to at least one photodetector.
Dependencies are inferred from the claim text.