270-km ultralong Raman fiber laser.
We analyze the physical mechanisms limiting optical fiber resonator length and report on the longest ever laser cavity, reaching 270 km, which shows a clearly resolvable mode structure with a width of approximately 120 Hz and peak separation of approximately 380 Hz in the radio-frequency spectrum.
Turitsyn
S K
SK
Photonics Research Group, Aston University, Birmingham, B4 7ET, United Kingdom.
Ania-Castañón
J D
JD
Babin
S A
SA
Karalekas
V
V
Harper
P
P
Churkin
D
D
Kablukov
S I
SI
El-Taher
A E
AE
Podivilov
E V
EV
Mezentsev
V K
VK