Abstract A radar transmitting system is disclosed for transmitting an optical pulse to a target comprising an optical cavity containing a laser incorporating a mode-locking means to build up an optical pulse. An optical switch is also provided within the cavity to convert the polarization of the optical pulse generated within the cavity. The optical switch comprises an electro-optical crystal driven by a time delayed driver circuit which is triggered by a coincident signal made from an optical pulse signal and a gating pulse signal. Upon being energized, the electro-optical crystal functions to convert the polarization of the optical pulse as it passes through the crystal. This converted optical pulse then strikes a polarization sensitive prism and is deflected out of the cavity toward the pending target in the form of a pulse containing most of the optical energy generated by the laser in the pulse build-up period. After striking the target, the reflected energy is picked up by a transceiver with the total travel time of the pulse being recorded. This travel time is a measure of the distance from the transceiver to the target.
An optical assemblY for producing a laser pulse for use in a highly precise clocked radar system comprising: an optical cavity including at least a first and second reflecting mirror; a laser means located within said cavity for oscillating a light beam between said reflecting mirrors; mode locking means within said cavity for building said light beam into an optical pulse; an electro-optical crystal capable of being electrically triggered for polarizing said optical pulse; photo detecting means for removing an optical signal during the reflection of said optical pulse from said first reflecting mirror and converting it into an electrical signal representing the position of said optical pulse at said first reflecting mirror; means for generating a constant train of gating pulses; a driver circuit means for producing an electrical triggering signal particularly adapted to radar clocking only when a gating pulse of said train of gating pulses is coincident with said electrical positioning signal representing said optical pulse at said first reflecting mirror; timing delay means connecting said driver circuit means and said electro-optical crystal for delaying said electrical triggering signal until said optical pulse passes through said electrooptical means towards said second reflecting mirror; and means for reflecting said polarized optical pulse out of said optical cavity including a polarization sensitive prism.
Claim 2
Dependent Claim
214 words
An optical assemblY for producing a laser pulse for use in a highly precise clocked radar system comprising: an optical cavity including at least a first and second reflecting mirror; a laser means located within said cavity for oscillating a light beam between said reflecting mirrors; mode locking means within said cavity for building said light beam into an optical pulse; an electro-optical crystal capable of being electrically triggered for polarizing said optical pulse; photo detecting means for removing an optical signal during the reflection of said optical pulse from said first reflecting mirror and converting it into an electrical signal representing the position of said optical pulse at said first reflecting mirror; means for generating a constant train of gating pulses; a driver circuit means for producing an electrical triggering signal particularly adapted to radar clocking only when a gating pulse of said train of gating pulses is coincident with said electrical positioning signal representing said optical pulse at said first reflecting mirror; timing delay means connecting said driver circuit means and said electro-optical crystal for delaying said electrical triggering signal until said optical pulse passes through said electrooptical means towards said second reflecting mirror; and means for reflecting said polarized optical pulse out of said optical cavity including a polarization sensitive prism.