whats interesting to read is Memo WFC 422 DA, copy attached, it helps make clearer the overall view of the system design for i was getting confused with the laser accellerator, now it comes clearer why he used IR led's paired with IR receivers....
what pointed me to that memo was a comment found on another blog thru google,
"the LED in the GP are not red, they are ultraviolet look at the patent Memo WFC 422 DA page 3-23, in addition to ionization of the area ambiente must use UV 400 to 250 nm is not IR."