Abstract: A multipass laser amplifier includes a mirror, a mirror device, a gain crystal, and refractive or diffractive beam-steering element. The gain crystal is positioned on a longitudinal axis of the multipass laser amplifier between the mirror and the mirror device. The beam-steering element is positioned on the longitudinal axis between the gain crystal and the mirror device. The beam-steering element has no optical power and deflects a laser beam, by refraction or diffraction, for each of multiple passes of the laser beam between the first mirror and the mirror device, such that each pass goes through the gain crystal for amplification of the laser beam and goes through a different respective off-axis portion of the beam-steering element. The no optical power of the beam-steering element enables maintaining a large beam size in the gain crystal, thereby facilitating amplification to high average power.

Abstract: A laser-resonator is terminated between an outcoupling mirror and a semiconductor saturable absorbing mirror (SESAM). A beam-translator including two spaced-apart mirrors is located in the laser resonator in a beam-path of laser radiation circulating in the laser-resonator. The two spaced apart mirrors are selectively rotatable as a pair about two axes perpendicular to each other for selectively translating an incidence point of the laser radiation on the SESAM.

Abstract: An optically pumped laser oscillator or amplifier includes a laser head having a gain medium exhibiting polarization-dependent absorption along two crystallographic axes and a pump source producing a pump beam. The medium's absorption coefficients along both said crystallographic axes are equal or the difference between the absorption coefficients relative to the lowest absorption coefficients R=Abs(?c??a)/(min(?c, ?a)) is reduced at least by a factor of two compared to the same relative difference between the two absorption coefficients at the medium's absorption peaks, used for conventional pumping by pumping with unpolarized or partially polarized pump light at a wavelength around which the average absorption coefficients along both of said crystallographic axes are equal or present a relative difference that is reduced by a factor of two or better compared to conventional pumping around the medium's absorption peaks.

Abstract: A device for extending the lifetime of a frequency-converting non-linear optical system (19) subjected to the radiation of an intense laser beam includes two plates (2, 3) with flat and parallel surfaces angled on the beam and elements for transverse rotation of the plates (2, 3) suitable for changing the angle of inclination of the first plate in an angular range (i20±?i2) to move the incident beam relative to the optical system (19), while minimizing the amplitude of movement of the output beam (37, 47) on the angular inclination range (i20±?i2) of the first plate. The application of the device in a non-linear optical source including one or more non-linear crystals (1, 16) is also described.

Abstract: An optically pumped laser oscillator or amplifier includes a laser head having a gain medium exhibiting polarization-dependent absorption along two crystallographic axes and a pump source producing a pump beam. The medium's absorption coefficients along both said crystallographic axes are equal or the difference between the absorption coefficients relative to the lowest absorption coefficients R=Abs(?c-?a)/(min(?c, ?a)) is reduced at least by a factor of two compared to the same relative difference between the two absorption coefficients at the medium's absorption peaks, used for conventional pumping by pumping with unpolarized or partially polarized pump light at a wavelength around which the average absorption coefficients along both of said crystal-lographic axes are equal or present a relative difference that is reduced by a factor of two or better compared to conventional pumping around the medium's absorption peaks.

Abstract: An optically pumped laser oscillator or amplifier including a laser head including a gain medium exhibiting polarization-dependent absorption along two crystallographic axes and a pump source producing a pump beam. The medium's absorption coefficients along both of the crystallographic axes are equal or the difference between the absorption coefficients relative to the lowest absorption coefficients is reduced at least by a factor of two compared to the same relative difference between the two absorption coefficients at the medium's absorption peaks. In some embodiments, the gain medium is a crystal, e.g., a Neodymium-doped Vanadate (Nd:YVO4) crystal, greater than 15 mm. In various embodiments, the optically pumped laser oscillator or amplifier includes two pump sources producing two pump beams.

Abstract: A device for extending the lifetime of a frequency-converting non-linear optical system (19) subjected to the radiation of an intense laser beam includes two plates (2, 3) with flat and parallel surfaces angled on the beam and elements for transverse rotation of the plates (2, 3) suitable for changing the angle of inclination of the first plate in an angular range (i20±?i2) to move the incident beam relative to the optical system (19), while minimising the amplitude of movement of the output beam (37, 47) on the angular inclination range (i20±?i2) of the first plate. The application of the device in a non-linear optical source including one or more non-linear crystals (1, 16) is also described.

Abstract: The present invention describes an optically end-pumped laser gain module, comprising a gain medium which is pumped by a light beam that has a larger size on the input face of the medium than on its output face.

Abstract: The present invention describes an optically end-pumped laser gain module, comprising a gain medium which is pumped by a light beam that has a larger size on the input face of the medium than on its output face.

Abstract: An optically pumped laser oscillator or amplified, comprising: a laser head including a gain medium exhibiting polarization-dependent absorption along two crystallographic axes; a pump source producing a pump beam wherein the medium's absorption coefficients along both said crystallographic axes are equal or the difference between the absorption coefficients relative to the lowest absorption coefficients R=Abs(&agr;c−&agr;a)/(min(&agr;c,&agr;a)) is reduced at least by a factor of two compared to the same relative difference between the two absorption coefficients at the medium's absorption peaks, used for conventional pumping either by pumping with unpolarized or partially polarized pump light at a wavelength around which the average absorption coefficients along both of said crystallographic axes are equal or present a relative difference that is reduced by a factor of two or better compared to conventional pumping around the medium's absorption peaks or by pumping with a combination of two pump