==== TCS ====
  * What thermal lensing @ 120K?
  * back of the envelope calculation
  * {{ :et_update_2017:et120vsadv_v1.png?400 |}}
  * TCS design must: robust, flexible
  * Actuators
     *	RHs:
	* Ok with room temperature TMs, what with cryogenics?
	* AdV design optimized to have the best uniformity:for ET segmented RH for higher order aberrations control (astigmatism)?
     * Recycling cavity projectors:
	* What material/temperature for CPs?
	* New wavelengths and lasers?
	* Thermal actuators? Depends on CP material…
	* LG33 modes require new approaches to compensating beam shaping.
   * Sensors
  * Adaptive optics for squeezing
     * Filter cavities tuning to improve MM: RHs may be the best option
     * Thermal actuators for squeezing beam MM before FC
     * Actuation on FC mirrors for reducing losses from mirrors figure errors