Graphene photodetectors for high-speed optical communications

Abstract

Moreover, owing to the unique band structure and exceptional electronic properties of graphene, high speed photodetectors with an ultra-wide operational wavelength range at least from 300 nm to 6 µm 10, 11 can be realized using this fascinating material.

Broadband graphene terahertz modulators enabled by intraband transitions

“…On the basis of their peculiar band structures, single-layer graphene and Bernal-stacked bilayer graphene have been proposed for novel terahertz [3][4][5][6][7] and optoelectronic devices 8 , with some successful experimental demonstrations [9][10][11][12] . Interband and intraband transitions under optical excitation in graphene have been investigated by various groups [13][14][15][16][17][18][19] .…”

“…Plasmonic effects in graphene were also recently observed 7 , which are important in the transition range from terahertz to infrared. Rooted in these understandings, several devices based on interband transitions have been demonstrated, including transparent electrodes 10 , photodetectors 11 , and broadband infrared electro-optical modulators 12 . However, to date, device applications of graphene optical properties in the terahertz range remain largely unexplored.…”

Controlled Generation of a p–n Junction in a Waveguide Integrated Graphene Photodetector

“…GHz [20,21,22], showing the promise of graphene for high-speed photodetection applications. Since then, several graphene-based photodetectors on Si waveguides [23,24,25,26,27] have been realized.…”

Surface Plasmon Polariton Graphene Photodetectors

“…The interference between surface plasmon polaritons and the incident wave introduces new functionalities, such as light flux attraction or repulsion from the contact edges, enabling the tailored design of the photodetector's spectral response. This architecture can also be used for surface plasmon bio-sensing with direct-electricreadout, eliminating the need of complicated optics.Graphene-based photodetectors (PDs) [1,2] have been reported with ultra-fast operating speeds (up to 262GHz from the measured intrinsic response time of graphene carriers [3]) and broadband operation from the visible and infrared [3][4][5][6][7][8][9][10][11][12][13][14][15][16] up to the THz [17][18][19]. The simplest graphene-based photodetection scheme relies on the metal-graphene-metal (MGM) architecture [5,7,8,11,[20][21][22], where the photoresponse is due to a combination of photo-thermoelectric and photovoltaic effects [5,7,8,11,[20][21][22].…”

“…E.g., if the two contacts shown in Fig.1b are placed across each other with a 600nm gap, then all the light accumulated from both contacts will be funneled close to only one of them. Such a scheme offers great flexibility in designing asymmetric contacts suitable for uniform illumination, potentially eliminating the need for different metallizations [6]. We explore this asymmetric contact design in Fig.2c (see insets).…”