Thank you for sharing these links. These may prove to be very helpful for Sam. And I want to mention here that I have already seen some papers which have achieved 40 Gbps data rate for these PON systems. They have made use of externally modulated Continuous wave lasers and also I have noticed that instead of Fabry parot filters , they have used Fiber Bragg grating as filter because of the response of these finer Bragg gratings. I hope this will definitely help Sam .