Abstract 1. A delay apparatus comprising means for generating a laser beam including a laser medium having a pair of end reflectors to form a feedback cavity, at least one of said reflectors being spaced from said laser medium, AN ACOUSTIC TRANSMITTING MEDIUM POSITIONED BETWEEN SAID LASER MEDIUM AND SAID SPACED REFLECTOR, MEANS RESPONSIVE TO AN ALTERNATING INPUT SIGNAL FOR GENERATING AN ACOUSTIC WAVE WITHIN SAID ACOUSTIC MEDIUM, SAID ACOUSTIC WAVE PROPAGATING WITHIN SAID ACOUSTIC MEDIUM AND INTERSECTING SAID LASER FEEDBACK RADIATION WHEREBY SAID LASER RADIATION IS DIFFRACTED AND PRODUCES AT LEAST ONE FREQUENCY SHIFTED COMPONENT TOGETHER WITH AN UNDIFFRACTED COMPONENT, A REFLECTING MIRROR POSITIONED IN THE PATH OF ONE OF SAID FREQUENCY SHIFTED COMPONENTS FOR REFLECTING SAID FREQUENCY SHIFTED COMPONENT BACK THROUGH SAID ACOUSTIC MEDIUM TO REINTERSECT SAID ACOUSTIC WAVE WHERE SAID FREQUENCY SHIFTED COMPONENT IS FURTHER DIFFRACTED PRODUCING A FURTHER FREQUENCY SHIFTED COMPONENT WHICH IS INSERTED INTO SAID FEEDBACK CAVITY, AND MEANS FOR PRODUCING FROM AT LEAST ONE OF SAID FREQUENCYSHIFTED COMPONENTS AN OUTPUT SIGNAL HAVING A FREQUENCY WHICH CONTAINS ANY DESIRED ODD OR EVEN INTEGRAL MULTIPLE OF SAID ALTERNATING INPUT SIGNAL FREQUENCY.
A delay apparatus comprising means for generating a laser beam including a laser medium having a pair of end reflectors to form a feedback cavity, at least one of said reflectors being spaced from said laser medium, an acoustic transmitting medium positioned between said laser medium and said spaced reflector, means responsive to an alternating input signal for generating an acoustic wave within said acoustic medium, said acoustic wave propagating within said acoustic medium and intersecting said laser feedback radiation whereby said laser radiation is diffracted and produces at least one frequency shifted component together with an undiffracted component, a reflecting mirror positioned in the path of one of said frequency-shifted components for reflecting said frequencyshifted component back through said acoustic medium to reintersect said acoustic wave where said frequency-shifted component is further diffracted producing a further frequencyshifted component which is inserted into said feedback cavity, and means for producing from at least one of said frequencyshifted components an output signal having a frequency which contains any desired odd or even integral multiple of said alternating input signal frequency.
Claim 2
Dependent Claim
179 words
A delay apparatus comprising means for generating a laser beam including a laser medium having a pair of end reflectors to form a feedback cavity, at least one of said reflectors being spaced from said laser medium, an acoustic transmitting medium positioned between said laser medium and said spaced reflector, means responsive to an alternating input signal for generating an acoustic wave within said acoustic medium, said acoustic wave propagating within said acoustic medium and intersecting said laser feedback radiation whereby said laser radiation is diffracted and produces at least one frequency shifted component together with an undiffracted component, a reflecting mirror positioned in the path of one of said frequency-shifted components for reflecting said frequencyshifted component back through said acoustic medium to reintersect said acoustic wave where said frequency-shifted component is further diffracted producing a further frequencyshifted component which is inserted into said feedback cavity, and means for producing from at least one of said frequencyshifted components an output signal having a frequency which contains any desired odd or even integral multiple of said alternating input signal frequency.
Claim 3
Dependent Claim
36 words
Apparatus as in claim 1 in which the said further frequency-shifted component is passed through one of said end reflectors to produce an output signal containing an even integral multiple of said alternating input signal frequency.
Claim 4
Dependent Claim
35 words
Apparatus as in claim 1 in which one of the said frequency-shifted components is passed through said reflecting mirror to produce an output signal containing an odd integral multiple of said alternating input signal frequency.
Claim 5
Dependent Claim
100 words
Apparatus as in claim 1 and including first and second mirrors positioned with respect to said spaced end reflector to form a resonant cavity, one of said first and second mirrors being partially transmitting and being positioned in the path of said laser feedback radiation, the undiffracted component of said feedback radiation at the resonant frequency of said resonant cavity being passed by said partially transmitting mirror into said resonant cavity and reflected back toward said laser medium, and the frequency-shifted component of said laser feedback radiation being reflected by said partially transmitting mirror out of said laser feedback cavity.
Claim 6
Dependent Claim
19 words
Apparatus as in claim 1 in which said laser feedback radiation intersects said acoustic wave at the Bragg angle.
Claim 7
Dependent Claim
14 words
Apparatus as in claim 1 in which said acoustic wave is a traveling wave.