Process and device for the generation of a single-frequency light ray

Claim 1

A process for the generation of a single-frequency light ray by laser means in which the laser''s self-oscillations are coupled by frequency modulation having a modulation frequency Omega which slightly deviates from the frequency difference between adjacent self-oscillations of the laser, comprising generating two frequency modulated rays, orthogonally polarized relative to each other and having respective carrier frequencies modulated by said modulation frequency and having equal frequency deviation from the carrier frequency, passing one of said rays as ordinary, and the other as extraordinary ray commonly through a birefringeant, optically nonlinear element whose optic axis is oriented at such an angle relative to the direction of the rays as to render the nonlinear interaction of the two orthogonally polarized rays maximal; and delaying one of these rays relative to the other by an oddnumbered multiple of a time T 1/2 Omega ; whereby an unmodulated light ray is obtained at the output of said birefringeant, optically non-linear element, the single frequency of which equals the sum of the carrier frequencies of said two frequency modulated rays.

Claim 5

A device for the generation of a single-frequency light ray comprising a laser oscillator in which the laser''s self-oscillations are coupled by frequency modulation, said oscillator comprising a laser amplifier having a longitudinal axis, one reflector arranged on said longitudinal axis opposite one end of said amplifier and a second reflector arranged on said longitudinal axis opposite the other end of said amplifier; a frequency modulator disposeD between one reflector and the laser amplifier; a birefringeant, optically nonlinear crystal having an optical axis oriented at an angle with respect to said longitudinal axis of said laser amplifier and being disposed between said laser amplifier and the second reflector; said laser''oscillator producing two orthogonally polarized, frequency modulated rays having a modulation frequency which slightly deviates from the frequency difference between adjacent self-oscillations, said angle being selected according to the characteristic of said birefringeant, non-linear element for causing maximum interaction between said rays; and means delaying said rays with respect to each other; whereby an unmodulated light ray is obtained whose frequency equals the sum of the carrier frequencies of said two frequency modulated rays.

Claim 6

A device for the generation of a single-frequency light ray comprising a laser oscillator in which the laser''s self-oscillations are coupled by frequency modulation, said oscillator comprising a laser amplifier having a longitudinal axis, one reflector arranged on said longitudinal axis opposite one end of said amplifier and a second reflector arranged on said longitudinal axis opposite the other end of said amplifier; a frequency modulator disposeD between one reflector and the laser amplifier; a birefringeant, optically nonlinear crystal having an optical axis oriented at an angle with respect to said longitudinal axis of said laser amplifier and being disposed between said laser amplifier and the second reflector; said laser''oscillator producing two orthogonally polarized, frequency modulated rays having a modulation frequency which slightly deviates from the frequency difference between adjacent self-oscillations, said angle being selected according to the characteristic of said birefringeant, non-linear element for causing maximum interaction between said rays; and means delaying said rays with respect to each other; whereby an unmodulated light ray is obtained whose frequency equals the sum of the carrier frequencies of said two frequency modulated rays.

Claim 7

A device for the generation of a single-frequency light ray comprising a laser oscillator in which the laser''s self-oscillations are coupled by frequency modulation, said oscillator comprising a laser amplifier having a longitudinal axis; a reflector disposed on said longitudinal axis at each end of said laser amplifier; a frequency modulator disposed between one reflector and the laser amplifier; said modulator being a birefringeant element having an optical axis oriented along said longitudinal axis; a non-linear birefringeant KDP crystal having an optical axis oriented at an angle with respect to said longitudinal axis; said laser oscillator producing two orthogonally polarized frequency modulated rays having a modulation frequency Omega which slightly deviates from the frequency difference Delta gamma between adjacent self-oscillations; said angle being selected according to the characteristic of said non-linear birefringeant crystal for causing maximum interaction between said two rays; and means delaying said rays with respect to each other; whereby an unmodulated light ray is obtained whose frequency equals the sum of the carrier frequencies of said modulated rays.

Claim 8

A device for the generation of a single-frequency light ray comprising a laser oscillator in which the laser''s self-oscillations are coupled by frequency modulation, said oscillator comprising a laser amplifier having a longitudinal axis; a reflector disposed on said longitudinal axis at each end of said laser amplifier; a frequency modulator disposed between one reflector and the laser amplifier; said modulator being a birefringeant element having an optical axis oriented along said longitudinal axis; a non-linear birefringeant KDP crystal having an optical axis oriented at an angle with respect to said longitudinal axis; said laser oscillator producing two orthogonally polarized frequency modulated rays having a modulation frequency Omega which slightly deviates from the frequency difference Delta gamma between adjacent self-oscillations; said angle being selected according to the characteristic of said non-linear birefringeant crystal for causing maximum interaction between said two rays; and means delaying said rays with respect to each other; whereby an unmodulated light ray is obtained whose frequency equals the sum of the carrier frequencies of said modulated rays.

Claim 9

A device for the generation of a single-frequency light ray comprising a laser oscillator in which the laser''s self-oscillations are coupled by frequency modulation, said oscillator comprising a laser amplifier; a first and a second reflector at each end thereof; a frequency modulator disposed between one reflector and the laser amplifier; said modulator including a birefringeant element having an optical axis oriented along the optical axis between said laser amplifier and the second reflector; an optically non-linear KDP crystal having an optical axis oriented at about 60* with respect to said optical axis, such angle being characteristic to said element for causing maximum interaction between said rays; said optically nonlinear KDP crystal disposed on said optical axis outside said second reflector; said laser oscillator producing two frequency modulated rays having a modulation frequency which slightly deviates from the frequency difference between adjacent self-oscillations; and means delaying said rays with respect to each other; whereby an unmodulated light ray is obtained whose frequency equals the sum of the carrier frequencies of said modulated rays.

Claim 10

A device for the generation of a single-frequency light ray comprising a laser oscillator in which the laser''s self-oscillations are coupled by frequency modulation, said oscillator comprising a laser amplifier; a first and a second reflector at each end thereof; a frequency modulator disposed between one reflector and the laser amplifier; said modulator including a birefringeant element having an optical axis oriented along the optical axis between said laser amplifier and the second reflector; an optically non-linear KDP crystal having an optical axis oriented at about 60* with respect to said optical axis, such angle being characteristic to said element for causing maximum interaction between said rays; said optically nonlinear KDP crystal disposed on said optical axis outside said second reflector; said laser oscillator producing two frequency modulated rays having a modulation frequency which slightly deviates from the frequency difference between adjacent self-oscillations; and means delaying said rays with respect to each other; whereby an unmodulated light ray is obtained whose frequency equals the sum of the carrier frequencies of said modulated rays.