UV Region Optimization

Many refractive optics materials absorb strongly in the UV. Fused silica is good low-absorbing material. If optics are cemented together, the spectral transmission of the cement should be tested. Balsam cements are to be avoided. 

One cardinal rule for IR optimization is to minimize the number and sizes of emitting sources that can be seen by the detector. This includes mechanical hardware such as secondary support structures and baffles, as well as seemingly empty spaces such as the central hole in the primary mirror. All of these emit black body radiation corresponding to their temperatures. 

Achieving these goals may require one or more of the following special telescope features  

Using an exchangeable secondary support structure. This enables elimination of oversize secondaries and baffles that might be needed for other kinds of observation. 

Using the secondary mirror as the aperture stop and making it sufficiently undersized that it cannot see past the rim of the primary mirror. 

---