BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Terahertz optics with graphene and nanostructured materials - Miss
  Shruti Badhwar (University of Cambridge\, Semiconductor Physics Group)
DTSTART:20130612T130000Z
DTEND:20130612T141500Z
UID:TALK45696@talks.cam.ac.uk
CONTACT:Teri Bartlett
DESCRIPTION:Plasmonics in graphene has recently received wide attention in
  the optics community. This is because the bound electromagnetic modes (pl
 asmons) are tightly confined to the surface and can also be tuned with car
 rier concentration. Interestingly\, with a doping of the order of 1012- 10
 13 cm-2 that can be achieved with external gates\, the plasmon resonance i
 n graphene appears in the infrared (IR) and terahertz (THz) range.\n\nIn t
 his talk\, I will explore the key question - how does graphene absorption 
 and hence any THz plasmon resonance in graphene evolve with doping\, type 
 of carriers and spatial distribution of carriers induced by the external g
 ate? An understanding of the physical mechanism\, correlating the spectra 
 with the type and spatial distribution of charge carriers is necessary and
  fundamental to the development of THz optical elements using graphene.\n\
 nI will then describe how the gate tunability of transmission through grap
 hene can be applied to develop THz modulators. For example\, we can indire
 ctly modulate the THz beam emitted from a quantum cascade laser\, which is
  a compact\, unipolar electrically driven source of THz radiation.\n\nWhil
 e graphene holds promise for most THz optical elements such as filters\, m
 odulators and detectors\, there is still a need to realize a compact room 
 temperature THz source for an integrated THz optical system. I will finall
 y describe how nanostructuring quantum cascade lasers might hold an answer
  to this question.\n
LOCATION:Mott Seminar Room\, Cavendish Laboratory\, Department of Physics
END:VEVENT
END:VCALENDAR