title: Optical detection of terahertz using nonlinear parametric upconversion.
abstract: We extend our work to perform sensitive, room-temperature optical detection of terahertz (THz) by using nonlinear parametric upconversion. THz radiation at 700 GHz is mixed with pump light at 1,550 nm in a bulk GaAs crystal to generate an idler wave at 1,555.6 nm. The idler is separated, coupled into optical fiber, and detected using a gated Geiger-mode avalanche photodiode. The resulting THz detector has a power sensitivity of 4.5 pW/Hz and a timing resolution of 1 ns.
authors.affiliation: MIT Lincoln Laboratory, 244 Wood Street, Lexington, Massachusetts 02420, USA. mjkhan@ll.mit.edu
authors.forename: M Jalal
authors.initials: MJ
authors.lastname: Khan
authors.forename: Jerry C
authors.initials: JC
authors.lastname: Chen
authors.forename: Sumanth
authors.initials: S
authors.lastname: Kaushik