220-fs erbium-ytterbium:glass laser mode locked by a broadband low-loss silicon/germanium saturable absorber.
We demonstrate femtosecond performance of an ultrabroadband high-index-contrast saturable Bragg reflector consisting of a silicon/silicon dioxide/germanium structure that is fully compatible with CMOS processing. This device offers a reflectivity bandwidth of over 700 nm and subpicosecond recovery time of the saturable loss. It is used to achieve mode locking of an Er-Yb:glass laser centered at 1540 nm, generating 220-fs pulses, with what is to our knowledge the broadest output spectrum to date.
Grawert
F J
FJ
Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA. felixg@mit.edu
Gopinath
J T
JT
Ilday
F O
FO
Shen
H M
HM
Ippen
E P
EP
Kärtner
F X
FX
Akiyama
S
S
Liu
J
J
Wada
K
K
Kimerling
L C
LC