Abstract: A contamination sensor for an optical sensor observation window includes a source, two prisms, a detector, and a controller. The source can emit a collimated light beam at an incident angle that is greater than a critical angle of an interface between a fluid and the window. The window has a refractive index greater than the refractive index of the fluid. The prisms can direct the collimated light beam within the window such that the collimated light beam reflects within a contamination detection zone of the window. The detector can receive the collimated light beam. The controller can communicate with the source and detector. The controller can calculate an emission/detection ratio defined by a difference between an amount of light emitted by the source and an amount of light that passes from the source to the detector by a total internal reflectance of the window.

Abstract: A contamination sensor for an optical sensor observation window includes a source, two prisms, a detector, and a controller. The source can emit a collimated light beam at an incident angle that is greater than a critical angle of an interface between a fluid and the window. The window has a refractive index greater than the refractive index of the fluid. The prisms can direct the collimated light beam within the window such that the collimated light beam reflects within a contamination detection zone of the window. The detector can receive the collimated light beam. The controller can communicate with the source and detector. The controller can calculate an emission/detection ratio defined by a difference between an amount of light emitted by the source and an amount of light that passes from the source to the detector by a total internal reflectance of the window.

Abstract: Apparatus and associated methods relate to a seeker for a Semi-Active Laser (SAL) guided missile. The seeker has a Short-Wave InfraRed (SWIR) camera and a Pulse Timing Logic (PTL) detector. The PTL detector has a SWIR photo detector axially aligned with a lens stack of the SWIR camera. The SWIR photo detector is configured to detect a sequence of SWIR pulses generated by a SAL target designator and reflected by a designated target. The PTL detector has a pulse timer configured to identify a sequence pattern of the detected sequence of SWIR pulses, and to predict a timing of a next SWIR pulse in the identified sequence pattern so as to synchronize exposure of the SWIR camera to capture a next image of the designated target at the predicted timing of the next SWIR pulse. Such exposure timing can advantageously improve the signal to noise ratio of the next image.

Abstract: Apparatus and associated methods relate to a seeker for a Semi-Active Laser (SAL) guided missile. The seeker has a Short-Wave InfraRed (SWIR) camera and a Pulse Timing Logic (PTL) detector. The PTL detector has a SWIR photo detector axially aligned with a lens stack of the SWIR camera. The SWIR photo detector is configured to detect a sequence of SWIR pulses generated by a SAL target designator and reflected by a designated target. The PTL detector has a pulse timer configured to identify a sequence pattern of the detected sequence of SWIR pulses, and to predict a timing of a next SWIR pulse in the identified sequence pattern so as to synchronize exposure of the SWIR camera to capture a next image of the designated target at the predicted timing of the next SWIR pulse. Such exposure timing can advantageously improve the signal to noise ratio of the next image.

Abstract: A laser transmitting system includes a laser source configured to transmit a laser beam at an original transmit intensity. The system also includes a laser intensity adjusting mechanism positioned in the path of the transmitted laser beam. The laser intensity adjusting mechanism is controllable to reduce the intensity of the laser beam from the original transmit intensity. The system also includes a controller coupled to the laser intensity adjusting mechanism. The controller is configured to automatically control the laser intensity adjusting mechanism based upon a safety criteria. Methods of controlling a laser transmitting system are also provided.

Abstract: Combined laser-based apparatus for determining both altitude and ground velocity of an aircraft comprises: a laser source for emitting pulsed laser beams substantially at a predetermined wavelength; a plurality of first optical elements for directing the laser beams from a first optical path to a second optical path which exits the first optical elements; a plurality of second optical elements configured to form a telescope, the second optical path and telescope field of view being fixedly co-aligned; an optical scanner for directing the second optical path and telescope field of view to desired ground positions while maintaining the co-alignment thereof; the telescope for receiving Doppler wavelength shifted reflections of the pulsed laser beams and directing the received ground reflections substantially over a third optical path; an optical filter element for separating the ground reflections of the third optical path into first and second portions that are dependent on the Doppler wavelength shift of the g

Abstract: A fiber optic filter edge detector of Doppler shifted light comprises: a laser source for emitting pulsed laser light substantially over a first fiber optic path; an optical lens for directing laser light emitted from the first fiber optic path to free-space and for receiving laser light returns from free-space and focusing the laser light returns to the first fiber optic path; an edge filter optical element fiber coupled to the first fiber optic path for receiving the laser light returns, the edge filter optical element operative to transmit a first portion of the laser light returns through a second fiber optic path and to reflect a second portion of the laser light returns through a third fiber optic path; and at least one light detector optically coupled to the second and third fiber optic paths.

Abstract: Combined laser-based apparatus for determining both altitude and ground velocity of an aircraft comprises: a laser source for emitting pulsed laser beams substantially at a predetermined wavelength; a plurality of first optical elements for directing the laser beams from a first optical path to a second optical path which exits the first optical elements; a plurality of second optical elements configured to form a telescope, the second optical path and telescope field of view being fixedly co-aligned; an optical scanner for directing the second optical path and telescope field of view to desired ground positions while maintaining the co-alignment thereof; the telescope for receiving Doppler wavelength shifted reflections of the pulsed laser beams and directing the received ground reflections substantially over a third optical path; an optical filter element for separating the ground reflections of the third optical path into first and second portions that are dependent on the Doppler wavelength shift of the g