摘要:
An optical transceiver is provided with a light pipe that intercepts, offsets and redirects a portion of the collimated transmit beam to create a virtual object in the receiver field-of-view to perform the BIT. The light pipe comprises an input face and first reflective surface in the transmitter FOV to intercept a portion of the beam along a first axis and re-direct the beam, a second reflective surface and output face in the receiver FOV that re-directs the portion of the beam along a second axis towards the receiver to create the virtual object in the receiver FOV and an optical channel that guides the redirected portion of the beam from the first reflective surface to the second reflective surface to offset the second axis from the first axis. The same detector used during normal operation of the transceiver is used to perform the BIT, which may include a simple “on/off” test or a radiometry test. The light pipe may be designed with an acceptance FOV that preserves collimation, which facilitates a measurement of alignment error between the transmit beam and receiver.
摘要:
An optical transceiver is provided with a light pipe that intercepts, offsets and redirects a portion of the collimated transmit beam to create a virtual object in the receiver field-of-view to perform the BIT. The light pipe comprises an input face and first reflective surface in the transmitter FOV to intercept a portion of the beam along a first axis and re-direct the beam, a second reflective surface and output face in the receiver FOV that re-directs the portion of the beam along a second axis towards the receiver to create the virtual object in the receiver FOV and an optical channel that guides the redirected portion of the beam from the first reflective surface to the second reflective surface to offset the second axis from the first axis. The same detector used during normal operation of the transceiver is used to perform the BIT, which may include a simple “on/off” test or a radiometry test. The light pipe may be designed with an acceptance FOV that preserves collimation, which facilitates a measurement of alignment error between the transmit beam and receiver.
摘要:
A control mechanism pins an optical fiber assembly on and off gimbal and between gimbals to route the assembly from an off-gimbal optical source across the gimbal axis/axes to an on-gimbal optical element so that the fiber assembly moves with the rotation of the gimbals. To accommodate a relatively large range of motion, the control mechanism is suitably configured to route the fiber assembly in a “U-shaped” loop with one end pinned off-gimbal in a stationary guide track and the other end pinned on-gimbal point in a rotating guide track so that the loose fiber assembly is constrained in the concentric tracks on and off gimbal. As the gimbal rotates, the loop seats onto one guiding track and peels off of the other guiding track while always maintaining its U shape. To accommodate a relatively small range of motion in other gimbal configurations, the control mechanism is suitably configured to pin one end of the fiber assembly off-gimbal and pass the fiber assembly directly over the gimbal where it is pinned on the other side of the gimbal. In a multi-gimbal pointer, the fiber assembly preferably exhibits different mechanical stresses as it crosses the different gimbals.
摘要:
A control mechanism pins an optical fiber assembly on and off gimbal and between gimbals to route the assembly from an off-gimbal optical source across the gimbal axis/axes to an on-gimbal optical element so that the fiber assembly moves with the rotation of the gimbals. To accommodate a relatively large range of motion, the control mechanism is suitably configured to route the fiber assembly in a “U-shaped” loop with one end pinned off-gimbal in a stationary guide track and the other end pinned on-gimbal point in a rotating guide track so that the loose fiber assembly is constrained in the concentric tracks on and off gimbal. As the gimbal rotates, the loop seats onto one guiding track and peels off of the other guiding track while always maintaining its U shape. To accommodate a relatively small range of motion in other gimbal configurations, the control mechanism is suitably configured to pin one end of the fiber assembly off-gimbal and pass the fiber assembly directly over the gimbal where it is pinned on the other side of the gimbal. In a multi-gimbal pointer, the fiber assembly preferably exhibits different mechanical stresses as it crosses the different gimbals.
摘要:
A Dewar apparatus includes a focal plane array (FPA) component coupled to an FPA carrier, and a cold bridge coupled to the FPA carrier. A cold shield is aligned with the optical axis and coupled to the cold bridge (e.g., via a direct-metal bond), and at least one cryostat enclosure is similarly coupled to the cold bridge such that it has an axis that is noncollinear with the optical axis.
摘要:
An off-axis reflective transmit telescope for a DIRCM system is mounted on the gimbal along a transmit-axis offset laterally from the optical axis of the receive telescope but nominally aligned with the line-of-sight of the receive telescope to transmit a laser beam. The telescope comprises an optical port optically coupled to a laser to receive and direct the laser beam away from the dome and a reflective optical assembly that reflects the laser beam through the dome. The reflective optical assembly comprises an off-axis mirror segment and a second optical element that together precompensate the laser beam for dome aberrations induced by the lateral offset of the transmit telescope's transmit axis from the optical axis. The off-axis mirror segment comprises a segment of a parent mirror having an aspheric curvature (e.g. parabolic, elliptical or higher-order asphere) about an axis of symmetry. The segment is offset so that it is not centered on the axis of symmetry of the parent mirror. The use of the off-axis mirror segment allows the optical port and any folding mirror to be positioned so that they do not obscure the reflected laser beam. The second optical element may be a segment of a dome corrector parent lens, a prism or a refractive lens formed on the front surface of the off-axis minor segment.
摘要:
A Dewar apparatus includes a focal plane array (FPA) component coupled to an FPA carrier, and a cold bridge coupled to the FPA carrier. A cold shield is aligned with the optical axis and coupled to the cold bridge (e.g., via a direct-metal bond), and at least one cryostat enclosure is similarly coupled to the cold bridge such that it has an axis that is noncollinear with the optical axis.
摘要:
An off-axis reflective transmit telescope for a DIRCM system is mounted on the gimbal along a transmit-axis offset laterally from the optical axis of the receive telescope but nominally aligned with the line-of-sight of the receive telescope to transmit a laser beam. The telescope comprises an optical port optically coupled to a laser to receive and direct the laser beam away from the dome and a reflective optical assembly that reflects the laser beam through the dome. The reflective optical assembly comprises an off-axis mirror segment and a second optical element that together precompensate the laser beam for dome aberrations induced by the lateral offset of the transmit telescope's transmit axis from the optical axis. The off-axis mirror segment comprises a segment of a parent mirror having an aspheric curvature (e.g. parabolic, elliptical or higher-order asphere) about an axis of symmetry. The segment is offset so that it is not centered on the axis of symmetry of the parent mirror. The use of the off-axis mirror segment allows the optical port and any folding mirror to be positioned so that they do not obscure the reflected laser beam. The second optical element may be a segment of a dome corrector parent lens, a prism or a refractive lens formed on the front surface of the off-axis minor segment.
摘要:
A method and apparatus is provided for producing a woven biased fabric in which the structural fibers are skewed from the fabric centerline. The method and apparatus are particularly designed for producing a woven biased structural fabric in which the structural fibers are oriented about 45.degree. to the fabric centerline, where the flimsy, open-knit nature of the fabric makes handling extremely difficult. Broadly speaking, the apparatus includes a fabric feeding station, slitting station, and winding station. The feeding station holds a roll of conventional structural fabric (parallel and perpendicular structural fibers) woven in a tube configuration and flattened into the roll form. The feeding station rotates the roll in a vertical plane as the fabric unwinds in a horizontal direction. The slitting station includes a cutter and a pair of slatter rolls, the rolls moving the tube of fabric in the horizontal direction while rotating the tube of fabric. The cutter makes a slit in the underside of the moving fabric tube at about a 45.degree. helix angle (or other desired angle). The slit fabric comes off the slatter rolls as a strip of extremely flimsy material with the structural fibers oriented about 45.degree. to the strip centerline. The flimsy strip of fabric is carried in a second direction (about 45.degree.) to the winding station by a moving sheet of plastic. The winding station rolls up both the supporting sheet and biased fabric.