From: luweitest@address.invalid   
      
   On 2015-10-14 5:58, Samuel M. Goldwasser wrote:   
   > ...   
   > To the original poster: You can probably pretyy much ignore what Phil   
   > and I have said.  If your path length difference is small compared to   
   > 150 mm (the cavity length of the 1107 tube), then it will be fine. ;-)   
   >   
   Thank you for all responded with helpful comments. I measure a glass   
   substrate with the ellipsometer, , and my concern is whether the laser   
   reflected from the front side and back side will interfere and take into   
   account as one light. Glass thickness will not exceed 5mm, so I can   
   safely take that for granted. But the ellipsometer still does not show a   
   regular pattern (eye-glass shaped) like one-side reflection, which I am   
   still confused.   
      
   --   
   Regards,   
   Lu Wei   
   PGP key ID: 0x92CCE1EA   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)