Nonlinear absorption edge properties of 1.3 - μ m GaInNAs saturable absorbers

• Published in: Applied physics letters Vol. 87; no. 13; pp. 132103 - 132103-3
• Main Authors: Grange, R., Rutz, A., Liverini, V., Haiml, M., Schön, S., Keller, U.
• Format: Journal Article
• Language: English
• Published: American Institute of Physics 26-09-2005
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.2058216

GaInNAs
1.3
-
μ
m
quantum-well saturable absorber mirrors are characterized with spectrally resolved nonlinear reflectivity measurements over
70
nm
around the broadened band edge. All important parameters such as saturation fluence
F
sat
, modulation depth
Δ
R
, and nonsaturable loss
Δ
R
ns
are obtained relative to the photoluminescence (PL) peak.
F
sat
has a minimum of
4
μ
J
∕
cm
2
10
nm
above the PL peak and
Δ
R
scales with the linear absorption even in the bandtail. The product
Δ
R
∙
F
sat
important to suppress
Q
-switching instabilities in mode-locked lasers decreases linearly with wavelength and reaches a minimum
20
nm
above the PL peak. We observed wavelength-independent nonsaturable losses of only about 10% of the maximum linear absorption. These results increase the understanding of optical and electronic properties of GaInNAs around the band edge.