Ming-Ying HSU, Han-Chao CHANG^*, and Shenq-Tsong CHANG

Instrument Technology Research Center, National Applied Research Laboratories, 20 R&D Road VI, Hsinchu Science-Based Industrial Park, Hsinchu 300, Taiwan, R.O.C.

(Received August 15, 2012; Accepted November 6, 2012)

The optical system lens temperature difference will cause optical aberration increase. This study is applying finite element method (FEM) and optical ray tracing; calculate off axis ray thermal optical path difference (OPD). The optical system temperature distribution is calculated from finite element simulation result and weighting temperature to each optical ray path. The simulation result shows off-axis ray major thermal optical aberrations are tilt and piston at this study.

Key words: FEM, OPD, ray tracing, aberration, off-axis

^*E-mail address: roman@itrc.narl.org.tw