Abstract: A laser arrangement for generating a twice frequency-converted laser radiation is disclosed, comprising the following: an active medium which by radiation of pump light generates a first laser radiation with a first frequency; a first laser resonator inside of which the first laser radiation circulates while resonating; a first non-linear crystal which is arranged inside of the first laser resonator and is provided and established to convert the first laser radiation into a second laser radiation with a second frequency that is higher than the first frequency; a second laser resonator inside of which the second laser radiation circulates while resonating; a second non-linear crystal which is arranged inside of the second laser resonator and is provided and established to convert the second laser radiation into a third laser radiation with a third frequency that is higher than the second frequency, wherein the first laser resonator and the second laser resonator are arranged relative to each other such that th

Abstract: A laser arrangement has a first optical element, provided and established to convert a first laser beam having a first frequency into a second laser beam having a second frequency, wherein the second frequency is higher than the first frequency, and has a second optical element, which is transmitting for the first laser beam and reflecting for the second laser beam, and which is provided and established to reflect the second laser beam in a direction of reflection. Both the first optical element and the second optical element are movably mounted in such a way that they can be moved relative to a direction of light propagation of the second laser beam.

Abstract: A laser arrangement has a first optical element, provided and established to convert a first laser beam having a first frequency into a second laser beam having a second frequency, wherein the second frequency is higher than the first frequency, and has a second optical element, which is transmitting for the first laser beam and reflecting for the second laser beam, and which is provided and established to reflect the second laser beam in a direction of reflection. Both the first optical element and the second optical element are movably mounted in such a way that they can be moved relative to a direction of light propagation of the second laser beam.

Abstract: A laser arrangement for generating a twice frequency-converted laser radiation is disclosed, comprising the following: an active medium which by radiation of pump light generates a first laser radiation with a first frequency; a first laser resonator inside of which the first laser radiation circulates while resonating; a first non-linear crystal which is arranged inside of the first laser resonator and is provided and established to convert the first laser radiation into a second laser radiation with a second frequency that is higher than the first frequency; a second laser resonator inside of which the second laser radiation circulates while resonating; a second non-linear crystal which is arranged inside of the second laser resonator and is provided and established to convert the second laser radiation into a third laser radiation with a third frequency that is higher than the second frequency, wherein the first laser resonator and the second laser resonator are arranged relative to each other such that th

Abstract: The invention relates to a device for reducing amplitude noise of a light radiation, comprising a first birefringent crystal, which has a first length along a direction of light propagation as well as a first optical axis; a polarization device; a light sensitive element, arranged in such a way that at least a part of a beam of light radiating through the first crystal and the polarization device when the device is in operation strikes the light sensitive element; and a control appliance which stands in operative connection with the first crystal and which is provided and arranged for using a signal generated by the light sensitive element as input variable and for applying a voltage signal as output signal to the first crystal to compensate for the amplitude noise.

Abstract: The invention relates to a device for reducing amplitude noise of a light radiation, comprising a first birefringent crystal, which has a first length along a direction of light propagation as well as a first optical axis; a polarization device; a light sensitive element, arranged in such a way that at least a part of a beam of light radiating through the first crystal and the polarization device when the device is in operation strikes the light sensitive element; and a control appliance which stands in operative connection with the first crystal and which is provided and arranged for using a signal generated by the light sensitive element as input variable and for applying a voltage signal as output signal to the first crystal to compensate for the amplitude noise.

Abstract: An optically pumped, in particular diode-pumped, continuous solid-state laser produces a primary laser beam whose frequency is converted into the visible or ultraviolet spectral range by means of one or more downstream passive resonators with non-linear crystals. At relatively low cost and complication it is provided that precisely two longitudinal laser modes of approximately equal amplitude are excited in the laser resonator. That achieves a high level of efficiency for the overall system and a very low noise level of the resulting frequency-converted laser beam. In one embodiment of the invention the frequency-converted radiation contains three or more adjacent frequencies. In another embodiment of the invention the frequency-converted laser radiation contains only one single frequency and therefore corresponds to the radiation of a monomode laser.

Abstract: A dye-laser includes a resonator formed between two mirrors. The resonator has a longitudinal Z-axis and transverse X- and Y-axes perpendicular to each other and perpendicular to the Z-axis. A beam of laser radiation circulates in the laser resonator generally in a path along the Z-axis. An optical arrangement is provided for expanding the circulating beam in the Y-axis in one circulation direction and correspondingly compressing the expanded beam in the opposite circulation direction. A diffraction grating having rulings parallel to an X-Z plane of the resonator is located in the resonator in the path of the Y-axis expanded beam.

Abstract: The invention concerns an optical resonant frequency converter comprising two mirrors and a non-linear crystal in a ring resonator arrangement for converting laser radiation into frequency-doubled radiation. Because of the refractive effect of the prism-shaped, non-linear crystal two mirrors are sufficient to form a ring resonator with a total of three optical elements. A suitable choice of the orientation of the crystal axes in relation to the laser beam direction reduces scatter in the crystal. In one embodiment the entry surface of the crystal is at the Brewster angle while the exit surface is perpendicular to the beam and has an antireflection coating. In another embodiment the converted beam is coupled out through a polarisation beam splitter layer on one of the crystal surfaces. In a further embodiment the crystal surfaces are cylindrically curved. That produces an elliptical beam profile in the crystal, which reduces the walk-off effect.

Abstract: The invention concerns an optical resonant frequency converter comprising two mirrors and a non-linear crystal in a ring resonator arrangement for converting laser radiation into frequency-doubled radiation. Because of the refractive effect of the prism-shaped, non-linear crystal two mirrors are sufficient to form a ring resonator with a total of three optical elements. A suitable choice of the orientation of the crystal axes in relation to the laser beam direction reduces scatter in the crystal. In one embodiment the entry surface of the crystal is at the Brewster angle while the exit surface is perpendicular to the beam and has an antireflection coating. In another embodiment the converted beam is coupled out through a polarisation beam splitter layer on one of the crystal surfaces. In a further embodiment the crystal surfaces are cylindrically curved. That produces an elliptical beam profile in the crystal, which reduces the walk-off effect.

Abstract: An arrangement for the resonant frequency doubling of multimode laser radiation with resonators is provided, including mirrors and an optically nonlinear material. The arrangement ensures a dispersion-free tuning of the length of a passive resonator, and enables the frequency doubling of a multimode laser, which is resonant simultaneously for all modes of the laser radiation, and which is achieved by pairs of mutually oppositely disposed movable elements of an optically transparent material, such as prisms (P1, P2). The prisms are brought into the beam path of the resonator (R), formed from mirrors (M1 to M4) and optically nonlinear material (BBO). The prisms are movable elements (P1, P2) which are connected to adjusting elements such as piezoactuators, so that the optical length of the resonator (R) can be tuned and compensation for dispersion attained.

Abstract: A method for the production of Gaussian intensity distribution in the beam profile of secondary radiation generated by non-linear optical processes, particularly frequency conversion and more particularly frequency doubling of a primary radiation beam. The non-linearly generated, secondary radiation beam is non-Gaussian in profile due to the walk-off effect and has a near field path near the non-linear optical material and a transition field path interconnecting the near field path with a remote, or far, field path. A Gaussian secondary beam profile of substantially circular cross-section is produced at a finite distance from the optical material by providing an optical system in the transition path which, taken as a whole, has no divergence altering or imaging effect on the secondary radiation beam.

Abstract: The invention pertains to a method and to a device for resonance enhancement, in particular for tunable frequency conversion of continuous laser radiation, in particular, with a resonator of mirrors and at least one refractive element. The purpose of the invention is to develop a method and a device of the described type, so that the frequency conversion of continuous laser radiation, in particular, will occur at high efficiency while avoiding the described disadvantages, and so that an improved tunability will be assured over the greatest possible wavelength range with regard to the incident wavelengths; this problem is solved in that a tuning of resonator length is performed by translation of at least one refractive element P. The resonator is formed from a first mirror M1, a second mirror M2, and of a refractive element P designed in trapezoidal shape, which performs the function of a prism.

Abstract: The invention relates to a method and device for frequency conversion, particularly for frequency doubling and particularly of continuous fixed frequency laser radiation, of semi-monolithic design with a ring resonator consisting of a mirror and an optically non-linear crystal. The objective of the invention is to develop a generic method and a device by means of which the frequency conversion, particularly the generation of the second harmonic from continuous fixed frequency laser radiation under avoidance of the disadvantages described, with high efficiency, with markedly enhanced opto-mechanical stability and a much simplified ease of production is assured, and is met by application of an electrical voltage to an annular piezo-adjuster 103 arranged between the mirror 101 and the crystal 102.