Abstract: A laser system, which is used in material processing to produce a radiation line of small width and uniform high intensity in the longitudinal direction, produces radiation that has different mode numbers M2 perpendicular to the propagation direction.

Abstract: A laser system, which is used in material processing to produce a radiation line of small width and uniform high intensity in the longitudinal direction, produces radiation that has different mode numbers M2 perpendicular to the propagation direction.

Abstract: A laser for generating pulsed laser radiation. An element is arranged in the resonator to generate laser radiation having the first wavelength by frequency conversion of the primary radiation. The resonator is switchable into a first state in which it is open to the primary radiation, and a second state in which it is closed to the primary radiation, and is open to laser radiation of the first wavelength in both states. A control unit switches the resonator from the first to the second state so that the primary radiation begins to oscillate and the pulse generation by frequency conversion begins, switches the resonator from the second to the first state, whereby primary radiation is coupled out from the resonator. It is possible to set the duration between both steps and/or the coupling-out behavior of the resonator to adjust the pulse duration via the control unit.

Abstract: A laser for generating pulsed laser radiation is provided. The laser includes a resonator, a laser-active medium arranged in the resonator, and an acousto-optic modulator arranged in the resonator. The modulator can be put in a first and a second state so as to set the resonator quality, the resonator quality being lower in the first state than in the second state, and comprising a control unit for controlling the modulator. The control unit effects phase-locked coupling of a high-frequency signal to be applied to the modulator in one of said two states, in order to generate a predetermined sound field in the modulator, and a switching signal designed to switch the modulator periodically between the two states.

Abstract: A laser for generating pulsed laser radiation. An element is arranged in the resonator to generate laser radiation having the first wavelength by frequency conversion of the primary radiation. The resonator is switchable into a first state in which it is open to the primary radiation, and a second state in which it is closed to the primary radiation, and is open to laser radiation of the first wavelength in both states. A control unit switches the resonator from the first to the second state so that the primary radiation begins to oscillate and the pulse generation by frequency conversion begins, switches the resonator from the second to the first state, whereby primary radiation is coupled out from the resonator. It is possible to set the duration between both steps and/or the coupling-out behavior of the resonator to adjust the pulse duration via the control unit.

Abstract: In an optical arrangement for obtaining a measurement signal for power measurement in lasers, the object is to reliably prevent laser radiation-induced contamination of the optically active surfaces with comparatively simple means, so that the optical properties of the surfaces, in particular the reflection coefficient, remain unchanged for a longer period of time than in the past. A beam splitter that is arranged on the laser beam axis and that directs a fraction of the laser beam onto a sensor by reflection, has optically active surfaces for the reflection that limit an opposing contamination-free, hermetically sealed inner space that is highly transmissive for the wavelength of the laser radiation.

Abstract: An excimer or molecular fluorine laser system includes a discharge chamber containing a gas mixture, multiple electrodes connected to a power supply circuit for energizing the gas mixture, a resonator for generating a laser beam, a processor, and means for monitoring an amplified spontaneous emission (ASE) signal of the laser, such as preferably an ASE detector. The processor receives a signal from the preferred ASE detector indicative of the ASE signal of the laser. Based on the signal from the ASE detector, the processor determines whether to initiate a responsive action for adjusting a parameter of the laser system.

Abstract: An F2-excimer laser has multiple closely-spaced spectral lines of interest around 157 nm, and one of the lines is selected by wavelength selection optics. The wavelength selection optics of a first preferred embodiment include a birefringent Brewster window enclosing the laser gas volume of the discharge chamber. The window preferably comprises MgF2 and is located at one end of the discharge chamber. One line is selected of the two when the optical thickness of the window is selected in coordination with rotatably adjustable, orthogonal refractive indices of the window. The transmissivity of the window is dependent on the orthogonal refractive indices and the optical thickness of the window. The wavelength selection optics of a second preferred embodiment include are at least partially within the laser active volume. In this way, line selection is performed in a manner which optimizes the combination of optical and discharge efficiency, resonator size and cost.

Abstract: It is the object of a device for converting a fundamental laser frequency to other frequencies to further increase the conversion efficiency in successive nonlinear processes at a low cost with respect to material and alignment and in a space-saving compact arrangement and to make use of the advantages of noncritical phase matching for this purpose. Between two nonlinear optical crystals for generating a first new frequency and for frequency mixing of a pair of laser beams which is generated in the first crystal and whose laser beams are polarized perpendicular to one another, there is arranged another birefringent crystal which is penetrated by the pair of laser beams and in which nonlinear optical characteristics are prevented, so that the pair of laser beams exits from the birefringent crystal with unchanged frequencies.

Abstract: A method is provided for determining the status of a gas mixture of a laser system including a gas discharge laser which generates an output beam and has a discharge chamber containing a gas mixture within which energy is supplied to the gas mixture by a power supply via application of a driving voltage to a discharge circuit. A master data set of an output parameter such as any of output beam energy, bandwidth, spectrum width, long axial beam profile, short axial beam profile, beam divergence, energy stability, energy efficiency, width of the discharge, temporal beam coherence, spatial beam coherence, spatial pulse width, amplified spontaneous emission and temporal pulse width versus an input parameter such as driving voltage is generated corresponding to an optimal gas mixture status, preferably after a new fill and typically at the factory, and alternatively following a new fill at the fab.

Abstract: A line-narrowed excimer or molecular fluorine laser system includes a gain medium surrounded by a resonator for generating a laser beam, a discharge circuit including a plurality of electrodes for energizing the gain medium and a line-narrowing unit within the resonator for narrowing the bandwidth of the laser system. The resonator includes a deformable resonator reflector. A technique for adjusting the bandwidth of the laser system includes adjusting a surface contour of the deformable resonator reflector. A desired bandwidth may be selected manually or using a processor which automatically controls the surface contour adjustment.

Abstract: An excimer or molecular fluorine laser system generates a laser output bandwidth of less than 0.6 pm, and preferably 0.5-0.4 pm or less. The laser resonator has a line-narrowing unit preferably including a grating, and preferably also a beam expander, and may include one or more etalons or other interferometric devices. The grating may be preferably a blazed grating having a blaze angle greater than 76°, and is preferably around 80°. The grating structure is preferably defined by the surface of the grating substrate. The substrate is preferably aluminum. The system may further include an amplifier for increasing the energy of the sub-0.6 nm output beam.

Abstract: A line-narrowed excimer or molecular fluorine laser system includes a gain medium surrounded by a resonator for generating a laser beam, a discharge circuit including a plurality of electrodes for energizing the gain medium and a line narrowing unit within the resonator for narrowing the bandwidth of the laser system. The resonator includes a deformable resonator reflector. A technique for adjusting the bandwidth of the laser system includes adjusting a surface contour of the deformable resonator reflector. A desired bandwidth may be selected manually or using a processor which automatically controls the surface contour adjustment.

Abstract: An F2-excimer laser has multiple closely-spaced spectral lines of interest around 157 nm, and one of the lines is selected by wavelength selection optics. The wavelength selection optics of a first preferred embodiment include a birefringent Brewster window enclosing the laser gas volume of the discharge chamber. The window preferably comprises MgF2 and is located at one end of the discharge chamber. One line is selected of the two when the optical thickness of the window is selected in coordination with rotatably adjustable, orthogonal refractive indices of the window. The transmissivity of the window is dependent on the orthogonal refractive indices and the optical thickness of the window. The wavelength selection optics of a second preferred embodiment include are at least partially within the laser active volume. In this way, line selection is performed in a manner which optimizes the combination of optical and discharge efficiency, resonator size and cost.

Abstract: A line narrowing unit for use within an excimer or molecular fluorine laser resonator includes a dispersive prism having antireflection coatings on entrance and exit surfaces. Entrance and exit angles and an apex angle are increased to enhance the dispersive power of the prism, while the antireflective coatings limit reflective losses. Preferably, a laser beam makes a non-symmetric pass through said prism. The apex angle is preferably greater than 65°, or even 75°, and the angle of incidence and the exit angle of the beam are each preferably greater than 65°. A beam expanding prism configured for enhanced beam expansion has an apex angle between within a range of 37.5° and 42.5°, and a beam incidence angle at the entrance surface of more than 65°, and an antireflection coating on preferably both the entrance and exit surfaces.

Abstract: An F2-excimer laser has multiple closely-spaced spectral lines of interest around 157 nm, and one of the lines is selected by wavelength selection optics. The wavelength selection optics of a first preferred embodiment include a birefringent Brewster window enclosing the laser gas volume of the discharge chamber. The window preferably comprises MgF2 and is located at one end of the discharge chamber. One line is selected of the two when the optical thickness of the window is selected in coordination with rotatably adjustable, orthogonal refractive indices of the window. The transmissivity of the window is dependent on the orthogonal refractive indices and the optical thickness of the window. The wavelength selection optics of a second preferred embodiment include are at least partially within the laser active volume. In this way, line selection is performed in a manner which optimizes the combination of optical and discharge efficiency, resonator size and cost.

Abstract: An F2-excimer laser has multiple closely-spaced spectral lines of interest around 157 nm, and one of the lines is selected by wavelength selection optics. The wavelength selection optics of a first preferred embodiment include a birefringent Brewster window enclosing the laser gas volume of the discharge chamber. The window preferably comprises MgF2 and is located at one end of the discharge chamber. One line is selected of the two when the optical thickness of the window is selected in coordination with rotatably adjustable, orthogonal refractive indices of the window. The transmissivity of the window is dependent on the orthogonal refractive indices and the optical thickness of the window. The wavelength selection optics of a second preferred embodiment include are at least partially within the laser active volume. In this way, line selection is performed in a manner which optimizes the combination of optical and discharge efficiency, resonator size and cost.

Abstract: An apparatus and method are provided for bandwidth narrowing of an excimer laser to &Dgr;&lgr;≈6 pm or less with high spectral purity and minimized output power loss. Output stability with respect to pulse energy, beam pointing, beam size and beam output location is also provided. The excimer laser includes an active laser medium for generating a spectral beam at an original wavelength, means for selecting and narrowing the broadband output spectrum of the excimer laser, a resonator having at least one highly reflecting surface, and an output coupler. Means for adapting a divergence of the resonating band within the resonator is further included in the apparatus of the invention. The divergence adapting causes the spectral purity to improve by between 20% and 50% and the output power to reduce by less than 10%. A method according to the invention includes selecting and aligning the divergence adapting means.

Abstract: An apparatus and method are provided for bandwidth narrowing of an excimer laser to &Dgr;&lgr;≈6 pm or less with high spectral purity and minimized output power loss. Output stability with respect to pulse energy, beam pointing, beam size and beam output location is also provided. The excimer laser includes an active laser medium for generating a spectral beam at an original wavelength, means for selecting and narrowing the broadband output spectrum of the excimer laser, a resonator having at least one highly reflecting surface, and an output coupler. Means for adapting a divergence of the resonating band within the resonator is further included in the apparatus of the invention. The divergence adapting causes the spectral purity to improve by between 20% and 50% and the output power to reduce by less than 10%. A method according to the invention includes selecting and aligning the divergence adapting means.

Abstract: A laser, especially an excimer laser, is designed to generate narrow-band radiation and comprises a laser resonator, including two reflecting elements (12, 14) between which there is disposed a laser active medium (10), and further comprises a group of several refractive dispersive elements (32, 34) arranged in the laser beam path and each deflecting, incident light at an angle &ggr;a,&ggr;b) which is specific of the wavelength of the incident light. It is provided to reduce variations of the emission wavelength which are temperature responsive and time dependent during burst operation by giving at least one of the refractive dispersive elements (32) a refractive index which increases as the temperature goes up and at least one of these elements (34) a refractive index which drops as the temperature rises.