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As the numerical aperture (NA) increasing and process factor k 1 decreasing in 193nm immersion lithography, polarization aberration (PA) of projection optics leads to image quality degradation seriously. Therefore, this work proposes a new scheme for compensating polarization aberration. By simulating we found that adjusting the illumination source partial coherent factors σ out is an effective method for decreasing the PA induced pattern critical dimension (CD) error while keeping placement error (PE) within an acceptable range. Our simulation results reveal that the proposed method can effectively compensate large PA in actual optics.

ESOPO will be a spectrograph of medium resolution for the 2.1 m telescope of the National Observatory at San Pedro Martir, Baja California, Mexico. It has been developed by the Instituto de Astronomia of the Universidad Nacional Autonoma de Mexico (IA-UNAM). The main goal of this instrument is to modernize the capabilities of making science with that particular telescope. It is planned to achieve a spectral resolution between 500 and 5000. ESOPO is split into two arms; each one specialized in a specific wavelength range covering together all the visible light. A very important issue in spectrographs is to avoid inside thermal gradients. Different temperatures in the optical elements produce mechanical movements and image quality degradation during an exposition. The error budget analysis developed for ESOPO allows establishing the required limits for temperature gradients. In this paper is described the thermal analysis of the spectrograph, including specifications, finite element models, thermal equations and expected thermal gradients.

Optomechanical sensitivity is the amount of image quality degradation in response to a certain deviation of any primary parameter of an optomechanical system. The sensitivity depends not only on the optical system but also on the mechanical layout. A technique for calculation of optomechanical sensitivity is presented. Only mechanical parameters are used as primary parameters. It is shown that airspaces or element tilts and decentrations cannot be used as primary parameters. The tolerances of an optomechanical system can be determined based on the computed sensitivity. Edge Function is used to evaluate the image quality for projection lenses. Software for realization of this technique has been developed. Examples of optimization of the optomechanical system of a projection lens using the developed technique are presented.