title: Ultrafast and widely tuneable vertical-external-cavity surface-emitting laser, mode-locked by a graphene-integrated distributed Bragg reflector.
abstract: We report a versatile way of controlling the unsaturated loss, modulation depth and saturation fluence of graphene-based saturable absorbers (GSAs), by changing the thickness of a spacer between a single layer graphene (SLG) and a high-reflection mirror. This allows us to modulate the electric field intensity enhancement at the GSA from 0 up to 400%, due to the interference of incident and reflected light at the mirror. The unsaturated loss of the SLG-mirror-assembly can be reduced to ∼0. We use this to mode-lock a vertical-external-cavity surface-emitting laser (VECSEL) from 935 to 981 nm. This approach can be applied to integrate SLG into various optical components, such as output coupler mirrors, dispersive mirrors or dielectric coatings on gain materials. Conversely, it can also be used to increase the absorption (up to 10%) in various graphene based photonics and optoelectronics devices, such as photodetectors.
authors: C A
authors: CA
authors: Zaugg
authors: Z
authors: Z
authors: Sun
authors: V J
authors: VJ
authors: Wittwer
authors: D
authors: D
authors: Popa
authors: S
authors: S
authors: Milana
authors: T S
authors: TS
authors: Kulmala
authors: R S
authors: RS
authors: Sundaram
authors: M
authors: M
authors: Mangold
authors: O D
authors: OD
authors: Sieber
authors: M
authors: M
authors: Golling
authors: Y
authors: Y
authors: Lee
authors: J H
authors: JH
authors: Ahn
authors: A C
authors: AC
authors: Ferrari
authors: U
authors: U
authors: Keller
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D006108:Graphite / Q000737:chemistry*; D007834:Lasers; D007909:Lenses; D012031:Refractometry / Q000295:instrumentation*; D018511:Systems Integration
chemical_list: D006108:Graphite