Carl-zeiss-stiftung

Carl-zeiss-smt Ag

Harald Sakowski

Peter Greve

Karl Brenner

Ulrich Wegmann

Martin Schriever

Wolfgang Emer

Martin Blumentritt

Steffen Lauer

A method of determining at least one optical property of a projection exposure system is described, wherein the exposure system includes a beam delivery system having a light source for generating an exposure optical beam having light of a first wavelength (&#x3bb;) and a second wavelength (&#x3bb;), wherein a first ratio is defined as an intensity of light &#x3bb;to an intensity of light &#x3bb;in the exposure optical beam. The method includes supplying at least one measuring optical beam including light of at least &#x3bb;to the projection optical system, detecting wavefronts having traversed the projection optical system, and determining an optical property in dependence of the detected wavefronts, wherein a second ratio of an intensity of light of &#x3bb;to an intensity of light of &#x3bb;in the measuring optical beam being incident on the detector of the wavefront detection system is less than the first ratio.

Method of determining optical properties and projection exposure system comprising a wavefront detection system

The invention is directed to a frequency-doubling solid state laser having pump light sources at opposite ends thereof. A folding and out-coupling mirror is antireflection coated on both sides with respect to the wavelength of the light generated by the pump light sources. The pump light sources include a total of four laser diodes with each laser diode generating 3 Watts of light power. An output power at 532 nm is obtained using a Nd:YAG laser rod and a frequency-doubling crystal made of potassium titanyl phosphate. The folding angle defined by the folding and out-coupling mirror is in the range of 10.degree. to 60.degree. and is typically 50.degree..

Frequency-doubling solid state laser

The invention is directed to a cooling arrangement for a semiconductor pump source which develops heat during operation. The cooling arrrangement includes a heat sink defining a seat for accommodating the pump source thereon and a cooling channel is formed in the heat sink for conducting a coolant therethrough to remove a major portion of the heat. A Peltier device is connected to the heat sink for finely controlling the temperature of the heat sink so as to permit the semiconductor pump source to emit radiation having a predetermined optional wavelength.

Cooling arrangement for a semiconductor pump source

Growing community of inventors

Lauchheim, Germany

Harald Sakowski