Hi Folks,
Based on my understanding QSFPP-4X10GE-LR QSFP+ 4x10GbE can be used as only 10GbE interface and not as a single 40GbE interface. You will need a 4X10G BREAKOUT cable to connect to the other end.
The below has few pointers on 10G-40G QSFPP Second Generation PTX Series PICs,
https://www.juniper.net/us/en/local/pdf/datasheets/1000495-en.pdf