From: jeedom74000@gmail.com   
      
   > > - the two detector approach is immune to laser output power    
   > > fluctuations but requires proper fringe spacing   
   > Or else a rotation mount, so that you can match a fixed photodiode    
   > spacing to your actual fringes--if the diodes are dx apart, twisting the    
   > mount effectively gives you dx cos theta, which can be significantly    
   > smaller.    
      
   Well I was thinking of using slit-style apertures in front of the (BPW43)   
   Photodiodes in order to optimize its efficiency, but that would prevent   
   rotating them. Anyhow, this is not much of an issue since adjusting the   
   distance between the photodiodes and    
   a diverging lens does the trick as well   
      
   > There's also nothing that says the diodes have to be looking at the same    
   > fringe, just that they be on opposite slopes, and that you not have a    
   > full fringe across the diameter of the diode.   
      
   Indeed   
      
   I have started to design a circuit, partly based on the article previously   
   mentioned and your parallel wiring proposal of the diodes, if you may confirm   
   this is what you meant:   
      
   https://flic.kr/p/2og5WDR   
      
   Thank you   
   Loic   
      
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