Multiple-beam interference patterns in optical fiber generated with ultrafast pulses and a phase mask.
We compare the cladding patterns present in grating structures fabricated with an ultrafast laser and a phase mask with a cw beam interference model. We find that the observed patterns agree well with the model results for picosecond pulses; however, for femtosecond pulses, we show that the full bandwidth and the pulsed nature of the sources must be considered because the pattern can be affected by group-velocity walk-off. An interesting consequence of order walk-off is the possibility of pure two-beam interference generation with a phase mask in the femtosecond pulse regime.
Smelser
Christopher W
CW
Communications Research Centre Canada, 3701 Carling Avenue, P.O. Box 11490, Station H, Ottawa, Ontario, Canada K2H 8S2. christopher.smelser@crc.ca
Mihailov
Stephen J
SJ
Grobnic
Dan
D
Lu
Ping
P
Walker
Robert B
RB
Ding
Huimin
H
Dai
Xiaoli
X