Hi, everybody.
Soon i will implement RAMAN-COP, and i woud like manualy calculate raman link to understand how it's work. I have CTP design of A and B stes. On witch site SMR-1, AMP-C and RAMAN-CTP. CTP calculate paramentrs on each site:
- SMR-1, LINE-TX add drop power =-10dbm,
- SMR-1, EXP-TX channel power = 5dbm
- AMP-C, LINE-TX channel power = 8dbm,
- RAMAN-CTP, RAMAN-TX lanch power = 772 mwatt
- RAMAN-CTP, RAMAN-TX ratio = 51.5 string
- RAMAN-CTP, RAMAN-TX expected gain = 18.8 dbm
- Distance= 226 km
- Fiber=G625 SMF 28E
- Ls=0,21dbm/km
I had taked some paramatrs from CTP:
- P0 (lanch power) = 772mwatt=0,772w
- Ls (loss per km) = 0,21dbm/km
parametrs from books:
- Lp (loss per km of pump laser) = Ls = 0,21dbm/km
- gr (raman gain efficiency) = 0,75 NOT SURE THAT IT CORRECT
I had make calculation in MATHCAD and i get near 18 dbm Gaint. On graph G(z) - function of gain depends on distance, P(s) - Signal power depends on distance (in formula -2 dbm, because -2 dbm after AMP-C). At the end i get that Gain -18dbm, singnal power at LINE-RX (RAMAN-CTP) = -35dbm. in attach graph.
Signal power from SMR-1, LINE-TX=-10dbm, next signal goes to AMP-C, Signal power -10dbm+8dbm=-2dbm. Then it goes to fiber (226*0,21bdm)=-47,46dbm, signal power -49,46dbm. On fiber works raman with Gain +8dbm, Signal power = -47,46 dbm + 18.8 dbm = -28,66dbm. Then it goes to SMR-1, EXP-TX (channel power) = 5dbm, Signal power = -28,66dbm + 5dbm = -23,66 dbm on SMR-1 EXP-TX.
And at the end i have some question regarding my calculations:
- am i correct calculate function G(z)?
- am i corectly get raman gain efficiency?
- when i calculate i get -35dbm, but when i calculate without graphs i get -28,66dbm, what i calculate not correct?
