Optical sensor with Tx/Rx aperture sharing element (ASE) for processing passive and active signals

An optical sensor, comprising:

• an outer gimbal that rotates around a first gimbal axis;
• an inner gimbal that rotates around a second gimbal axis orthogonal to the first gimbal axis to point an optical axis in a multi-dimensional space defined by said first and second gimbal axes;
• a common Tx/Rx telescope mounted on the inner gimbal along the optical axis;
• an off-gimbal optical source that emits an optical transmit signal at a first transmission wavelength at a fixed off-gimbal access point;
• an off-gimbal detector responsive to light at a plurality of wavelengths;
• a free-space optical path along the first and second gimbal axes to couple light from the common Tx/Rx telescope to the off-gimbal detector;
• and
• an off-gimbal aperture sharing element (ASE) positioned in a common Tx/Rx aperture in the free-space optical path, said ASE comprising a center region and an annular region,
• wherein the optical transmit signal is directed from the fixed off-gimbal axis point onto the center region of the ASE to free-space couple the optical transmit signal into the free-space optical path and to the common Tx/Rx telescope for transmission towards a scene,
• wherein light returned from the scene and received by the common Tx/Rx telescope is directed onto the annular region of the ASE to free-space couple the light to the off-gimbal detector to image the scene;
• wherein said common Tx/Rx telescope produces an intermediate image at a first field stop from received light, said free-space optical path including gimbal optics that couple light across the first and second gimbal axes and off-gimbal focusing optics that relay the intermediate image of the scene to the off-gimbal detector, wherein the off-gimbal ASE is positioned off-gimbal within the off-gimbal focusing optics.

An optical sensor, comprising:

• an outer gimbal that rotates around a first gimbal axis;
• an inner gimbal that rotates around a second gimbal axis orthogonal to the first gimbal axis to point an optical axis in a multi-dimensional space defined by said first and second gimbal axes;
• a common Tx/Rx telescope mounted on the inner gimbal along the optical axis;
• an off-gimbal optical source that emits an optical transmit signal at a first transmission wavelength at a fixed off-gimbal access point;
• an off-gimbal detector responsive to light at a plurality of wavelengths;
• a free-space optical path along the first and second gimbal axes to couple light from the common Tx/Rx telescope to the off-gimbal detector;
• an off-gimbal aperture sharing element (ASE) positioned in a common Tx/Rx aperture in the free-space optical path, said off-gimbal ASE comprising a center region and an annular region,
• wherein the optical transmit signal is directed from the fixed off-gimbal axis point onto the center region of the off-gimbal ASE to free-space couple the optical transmit signal into the free-space optical path to the common Tx/Rx telescope for transmission towards a scene,
• wherein light returned from the scene including a returned optical transmit signal at the first transmission wavelength and passive emissions at a plurality of other wavelengths and received by the common Tx/Rx telescope is directed onto the annular region of the off-gimbal ASE to free-space couple the light towards the off-gimbal detector to image the scene;
• and
• a filter wheel positioned between the off-gimbal ASE and the off-gimbal detector, said filter wheel including at least a first filter segment configured to pass the returned optical transmit signal at the first transmission wavelength and a second filter segment configured to block the returned optical transmit signal and pass the passive emissions from at least some of the plurality of other wavelengths;
• wherein said off-gimbal detector alternately produces active and passive images of the scene.

An optical sensor, comprising:

• a common Tx/Rx telescope mounted along an optical axis;
• an optical source that emits an optical transmit signal at a first transmission wavelength;
• a detector responsive to light at a plurality of wavelengths;
• a free-space optical path to couple light from the common Tx/Rx telescope to the detector;
• and
• an aperture sharing element (ASE) positioned in a common Tx/Rx aperture at a fixed angle to the free-space optical path, said ASE comprising a center region and an annular region one of said center and annular regions configured to be optically transparent at the first transmission wavelength and the other to optically reflective at the first transmission wavelength;
• wherein the optical transmit signal is directed onto the center region of the ASE to free-space couple the optical transmit signal at the first transmission wavelength into the free-space optical path to the common Tx/Rx telescope for transmission towards a scene;
• wherein light including the first transmission wavelength and a plurality of other wavelengths returned from the scene and received by the common Tx/Rx telescope is directed onto the annular region of the ASE to free-space couple the light to the detector to image the scene.

An optical sensor, comprising:

• a common Tx/Rx telescope mounted along an optical axis;
• an optical source that emits an optical transmit signal at a first transmission wavelength;
• a detector responsive to light at a plurality of wavelengths;
• a free-space optical path to couple light from the common Tx/Rx telescope to the detector;
• an aperture sharing element (ASE) positioned in a common Tx/Rx aperture in the free-space optical path, said ASE comprising a center region and an annular region;
• wherein the optical transmit signal is directed onto the center region of the ASE to free-space couple the optical transmit signal into the free-space optical path to the common Tx/Rx telescope for transmission towards a scene;
• wherein light returned from the scene and received by the common Tx/Rx telescope is directed onto the annular region of the ASE to free-space couple the light to the detector to image the scene;
• and
• a filter wheel positioned between the ASE and the detector, said filter wheel including at least a first filter segment configured to pass a returned optical transmit signal at the first transmission wavelength and a second filter segment configured to block the returned optical transmit signal and pass passive emissions from at least some of the plurality of other wavelengths,
• wherein said detector alternately produces active and passive images of the scene.

An optical sensor, comprising:

• a common Tx/Rx telescope mounted along an optical axis;
• an optical source that emits an optical transmit signal at a first transmission wavelength;
• a detector responsive to light at a plurality of wavelengths;
• a free-space optical path to couple light from the common Tx/Rx telescope to the detector;
• and
• an aperture sharing element (ASE) positioned in a common Tx/Rx aperture in the free-space optical path, said ASE comprising a center region and an annular region;
• wherein the optical transmit signal is directed onto the center region of the ASE to free-space couple the optical transmit signal into the free-space optical path to the common Tx/Rx telescope for transmission towards a scene;
• wherein light returned from the scene and received by the common Tx/Rx telescope is directed onto the annular region of the ASE to free-space couple the light to the detector to image the scene;
• wherein said common Tx/Rx telescope produces an intermediate image at a first field stop from received light, said free-space optical path including focusing optics that relay the intermediate image of the scene to the detector, wherein the ASE is positioned within the focusing optics.