Active control of all-fibre graphene devices with electrical gating

Abstract

Active manipulation of light in optical fibres has been extensively studied with great interest because of its compatibility with diverse fibre-optic systems. While graphene exhibits a strong electro-optic effect originating from its gapless Dirac-fermionic band structure, electric control of all-fibre graphene devices remains still highly challenging. Here we report electrically manipulable in-line graphene devices by integrating graphene-based field effect transistors on a side-polished fibre. Ion liquid used in the present work critically acts both as an efficient gating medium with wide electrochemical windows and transparent over-cladding facilitating light–matter interaction. Combined study of unique features in gate-variable electrical transport and optical transition at monolayer and randomly stacked multilayer graphene reveals that the device exhibits significant optical transmission change (>90%) with high efficiency-loss figure of merit. This subsequently modifies nonlinear saturable absorption characteristics of the device, enabling electrically tunable fibre laser at various operational regimes. The proposed device will open promising way for actively controlled optoelectronic and nonlinear photonic devices in all-fibre platform with greatly enhanced graphene–light interaction.

Optical modulators with 2D layered materials

“…External cavity optical processing (e.g., amplification, frequency conversion and pulse compression) also has been demonstrated as a convenient way to push the output performance 8,11 , e.g., the wavelength accessibility, the pulse duration and the output power and pulse energy. A particularly innovative approach is currently undergoing development in order to improve the ultrafast laser performance with a combined active and passive modulation function in 2D materials [63][64][65][66] . Figure 2c proposes a high-performance ultrafast laser enabled with 2D material based photonic integrated circuit.…”

“…Therefore, it is crucial to overcome the low absorption in monolayer 2D materials in order to increase the modulation depth. Various methods have been proposed or demonstrated to improve the modulation depth by using multi-layer devices (including few-layer graphene 25 or stacked monolayer graphene 83 devices), reflection-mode 84 , patterned structure 95 , interference enhancement 84 , evanescent-mode coupling 65 and cavities 96 . Scale bar, 8ps.…”

2D Saturable Absorbers for Fibre Lasers

“…All of these materials offer distinct, yet complementary properties [10,11,17,18] and, hence, new opportunities for optical applications in fibre-based systems. The possibility of combining layers of 2D materials to form van der Waals heterostructures also offers an exciting prospect for a wide range of new engineerable photonic devices [19], as does the potential to vary nanomaterial properties through their growth conditions, doping and electronic control [20,21].…”

Active backstepping control of combined projective synchronization among different nonlinear systems

“…There are only a few papers on the combination projective synchronization [28,29]. On the other hand, the active control scheme [30][31][32] and backstepping design [33,34] have been widely recognized as two powerful design methods to control chaotic systems in recent years. The active control method is easier to manipulate so that it is used widely to control chaotic systems.…”