RU2002127171A - MULTI-PASS LASER RADIATION AMPLIFIER - Google Patents

Claims (12)

1. A multi-pass laser radiation amplifier comprising a pump device, a master oscillator, an active element and a system of laser reflectors, the axis of radiation of the master oscillator passing through the first end of the active element at an angle to the longitudinal axis of symmetry of the active element, characterized in that the laser reflector system radiation is made in the form of rotary optical reflective elements, the first blind mirror, installed to enable at least one additional about the amplification passage of the radiation of the master oscillator, and a stable optical resonator, including a second blind and output translucent flat mirror, while the optical axis of the optical resonator of the master oscillator and the axis of the radiation beam of the master oscillator form an angle γ with the longitudinal axis of symmetry of the active element, satisfying the condition

where 2R ₀ is the aperture of the active element; L _a is the length of the active element; r ₀ is the radius of the radiation beam of the master oscillator, moreover, the output translucent flat mirror is installed with the possibility of sequential optical conjugation by means of rotary optical reflective elements through the second end of the active element with the first blind mirror to enable the first amplifying passage of the radiation of the master oscillator crossing the optical axis of the optical resonator of the master oscillator at an angle δ satisfying the condition

2. The amplifier according to claim 1, characterized in that an aperture of diameter d << 2R ₀ is additionally inserted into it to select the transverse modes, mounted between the active element and the output translucent flat mirror with the possibility of sequential optical conjugation of the diaphragm and the output translucent flat mirror. 3. The amplifier according to claim 1 or 2, characterized in that at least one active element is additionally introduced into it, while all active elements are installed to form a two-pass amplifier cascade, while the output end of the previous active element is optically coupled to the input end of the subsequent an active element, the first blind mirror being installed on the side of the latter during the first amplification passage of the output end of the last in the cascade of amplifiers of the active element on its longitudinal axis of symmetry and optically connected with the output end of the last in the cascade of amplifiers of the active element with the possibility of reflection of the radiation of the master oscillator inside the last in the cascade of amplifiers of the active element through its output for the case of the first amplification pass of the radiation of the master oscillator end to enable at least one additional amplification pass of the radiation of the master oscillator. 4. The amplifier according to claim 3, characterized in that all active elements are installed sequentially along the longitudinal axis of symmetry of the amplifier in the reverse direction of the primary input radiation of the master oscillator direction. 5. The amplifier according to claim 3, characterized in that all active elements are mounted parallel to each other, while the output end of the previous active element is optically coupled to the input end of the subsequent active element by means of newly introduced additional rotary optical reflective elements. 6. The amplifier according to claim 5, characterized in that all active elements are installed in parallel with respect to the pump device with the possibility of generating and amplifying at least two of the active elements from one pump device to create inverse population. 7. The amplifier according to any one of claims 1 to 6, characterized in that the first blind mirror is made flat. 8. The amplifier according to claim 5 or 6, characterized in that the rotary optical reflective element to enable the first amplifying passage of the radiation of the master oscillator directly to the second end of the first active element and the first blind mirror is made in the form of a telescopic pair of spherical convex and blind concave mirrors , the spherical convex mirror formed on the transparent enlightened on both sides of the concave-convex substrate with a radius of curvature R ₁ of the working surface, ensuring total of complements aperture 2R ₀ active element through the second end of the first active element in the first amplifying pass master oscillator radiation, and a reflective coating on the central portion of diameter d ₁ which satisfies the condition d ≤ d ₁ ≤ 2R _0, and is set on the longitudinal axis of symmetry of the first active element the ability to reflect the radiation of the master oscillator through the second end into the first active element along this axis, and a blind concave mirror is made with a radius of curvature R _{2 of the} working surface, providing A complete filling of the aperture of the active element through the input end at the beginning of the second amplification passage of the radiation of the master oscillator of the last in the cascade of amplifiers of the active element, and is installed on the longitudinal optical axis of symmetry of the last in the cascade of amplifiers of the active element with the ability to move along this longitudinal optical axis and reflect radiation through the input end at the beginning of the second amplifying passage of the radiation of the master oscillator into the last in the cascade of amplifiers of the active element s of the longitudinal axis, wherein the difference between the radii of curvature of the spherical convex and concave mirrors deaf expressed by the relation

where L _1, ... _{, n} is the length of the active elements in the cascade of amplifiers. 9. The amplifier according to claim 1, characterized in that the second blind mirror of the optical resonator is made in the form of a flat circle with a diameter d ₂ ≥ d and a Gaussian profile of the distribution of the reflection coefficient, mounted on the cut surface in the form of a chamfer of the input end face of the first active element, wherein the reflecting surface of the second blank mirror in the form of a flat circle is located on the optical axis of the optical resonator of the master oscillator and is perpendicular to it. 10. The amplifier according to claim 9, characterized in that the output translucent flat mirror of the optical resonator is made in the form of a flat circle with a diameter d ₂ ≥ d and a Gaussian profile of the distribution of the reflection coefficient, mounted on the cut surface in the form of a chamfer of the second end of the first active element, when this reflecting surface of the output translucent mirror in the form of a flat circle is located on the optical axis of the optical resonator of the master oscillator and perpendicular to it. 11. The amplifier according to any one of claims 1, 3-6, 8 and 9, characterized in that it additionally includes a resonator Q-factor modulator mounted on the optical axis of the optical resonator of the master oscillator between the active element and the output translucent flat mirror and optically coupled to output flat translucent mirror. 12. The amplifier according to claim 2, characterized in that it additionally includes a resonator Q-factor modulator mounted on the optical axis of the optical resonator of the master oscillator between the active element and the diaphragm and optically coupled to the diaphragm.