**7.3 Temperature stabilization: arrange unavoidable thermal sources in enclosure only**

It is better to keep unstable thermal sources outside the enclosure of the profiler as much as possible. The best choice: No drive motor is placed inside the enclosure.

It is necessary to apply monolithic wave-front splitting beam splitter (WSBS) to maintain good thermal stability.

Following is temperature variations of light source and CCD camera for reference:


Fig. 28. a) Temperature variations of CCD board and control board; b) Temperature rising of diode laser
