Cymer, Inc.

Max-Planck-Gesellschaft Zur F&#xf6;rderung Der Wissenschaften E. V.

Rhinolight Corporation

Zsolt Bor

Eckehard D Onkels

William N Partlo

Igor Vladimirovich Fomenkov

Richard G Morton

Richard C Ujazdowski

Vladimir B Fleurov

Jean-Marc Hueber

Michael C Cates

Lajos Kemény

Gábor Szabó

Dmitri V Gaidarenko

Ferenc Ignácz

Béla Rácz

Attila Dobozy

Alexander Mueller

An electric discharge, narrow band gas laser with improvements in wavelength stability. Improvements result from reduced laser beam directional fluctuations or fast correction of those fluctuations. Applicant has discovered, using an extremely sensitive knife edge optical technique, that gas discharge laser windows in a trapezoidal configuration were causing slight wavelength perturbations when laser gas density varied during laser operation. The optical technique involves using test laser beam directed through the discharge region of the gas discharge laser, blocking a portion of the beam with a knife edge and measuring the non-blocked portion of the beam to monitor beam deflection. With this technique, Applicant can measure beams deflection with an accuracy of about 0.3 microradians and with a time response of about 1 microsecond. An improvement in wavelength stability is achieved by orienting the laser chamber windows parallel to each other at a selected angle between 40&#xb0; and 70&#xb0; with the laser beam direction. The change eliminates wavelength fluctuations caused by laser beam direction fluctuation caused pressure fluctuations and the prism effect resulting from windows mounted in a prior art trapezoidal configuration. Beam directional fluctuations can also be measured during laser operation using the knife edge technique or similar fast response techniques such as a quadrant detector and the measured values can be used in a feedback arrangement along with fast wavelength control unit to compensate for changes in beam direction. In addition techniques for reducing the causes of beam direction fluctuations are disclosed. These include techniques for minimizing the effects of laser discharge caused pressure waves.

Narrow band electric discharge gas laser having improved beam direction stability

A phototherapeutical apparatus and method are described. The apparatus includes an ultraviolet light source, an optical guidance system, and a patient interface. The patient interface is insertable at least partially into a body cavity and is operable to apply the guided ultraviolet light to a tissue surface of a body cavity. The method includes providing the phototherapeutical apparatus, preparing for the application of the phototherapeutical apparatus, inserting the patient interface at least partially into a body cavity, and applying the ultraviolet light by the patient interface to a tissue surface of a body cavity, wherein the tissue of the body cavity has an inflammatory or a hyperproliferative disease. The inflammatory diseases include rhinitis, sinusitis and rhinosinusitis. A photochemotherapeutical method is also described, using photosensitizing substances, such as psoralen before treatment with ultraviolet light. The phototherapeutical method is also effective for the prevention of inflammatory or hyperproliferative diseases.

Phototherapeutical apparatus and method for the treatment and prevention of diseases of body cavities

A gas discharge laser having a laser chamber with two elongated electrode elements, each having a discharge section having an optimum array of discharge peaks and sputter cavities. The sputter cavities provide sputter metal ions to contribute to a plasma between the electrodes and support a glow-type discharge. The peaks provide very high fields which produce a very large number of filament-type discharges. The electrodes erode gradually but since the discharge region is confined to the array of discharge peaks and sputter cavities, the shape of he discharge remains approximately constant for billions of pulses. A pulse power system provides electrical pulses of at least 2J at rates of at least 1 KHz. A blower circulates laser gas between the electrodes at speeds of at least 5 m/s and a heat exchanger is provided to remove heat produced by the blower and the discharges.

Discharge laser having electrodes with sputter cavities and discharge peaks

Methods and structural changes in gas discharge lasers for minimizing wavelength chirp at high pulse rates. Applicants have identified the major cause of wavelength chirp in high pulse rate gas discharge lithography lasers as pressure waves from a discharge reflecting back to the discharge region coincident with a subsequent discharge. The timing of the arrival of the pressure wave is determined by the temperature of the laser gas through which the wave is traveling. During burst mode operation, the laser gas temperature in prior art lasers changes by several degrees over periods of a few milliseconds. These changing temperatures change the location of the coincident pressure waves from pulse to pulse within the discharge region causing a variation in the pressure of the laser gas which in turn affects the index of refraction of the discharge region causing the laser beam exiting the rear of the laser to slightly change direction. This change in beam direction causes the grating in the LNP to reflect back to the discharge region light at a slightly different wavelength causing the wavelength chirp. Solution to the problem is to include in the laser chamber structural elements to moderate or disperse the pressure waves and to maintain the laser gas temperature as close as feasible to constant values.

Electric discharge laser with acoustic chirp correction

For the acquisition of data for determining the duration and chirp (frequency modulation) of a single ultrashort laser radiation pulse said pulse is split into two partial pulses which are each conducted through one of two TREACY compressors having different group delay dispersions and then recorded in succession on the same time basis with a streak camera.

Method and apparatus for the acquisition of data for determining the

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Szeged, Hungary

Zsolt Bor