摘要 |
<p>A light projection optical system is presented. The system comprises a cooling chamber containing: a light source operative at a cool temperature being lower than 240K; a cooler unit capable of cooling said light source to said cool temperature during the light source operation,- an optical window permitting light emergence outside from the cooling chamber; and an optical unit accommodated in the optical path of light emitted by said light source and enabling emergence of this light through said optical window outside from the cooling chamber.</p> |