Title :
Tunable Terahertz Signal Generation by Chirped Pulse Photomixing
Author :
Stigwall, Johan ; Wiberg, Andreas
Author_Institution :
Photonics Lab., Chalmers Univ. of Technol., Goteborg
fDate :
6/15/2007 12:00:00 AM
Abstract :
Tunable signal generation in the gigahertz to terahertz range was demonstrated by photomixing of a chirped optical pulse and its time-delayed replica. The chirped pulses were created by chromatically dispersing femtosecond pulses from a mode-locked fiber ring laser, and frequency tuning was achieved by adjusting the time delay and/or the amount of group velocity dispersion. It is shown that the signal phase is locked to the femtosecond-laser pulses and that an extinction ratio close to 100% can be obtained. Analytical calculations on the signal chirp introduced by higher order dispersion are also presented and compared with the experimental data
Keywords :
chirp modulation; delays; high-speed optical techniques; microwave photonics; optical fibre dispersion; submillimetre wave generation; chirped optical pulse; chirped pulse photomixing; chromatic dispersion; extinction ratio; femtosecond pulses; fiber ring laser; frequency tuning; group velocity dispersion; higher order dispersion; mode-locked laser; signal chirp; signal phase locking; terahertz signal generation; time delay; time-delayed replica; tunable signal generation; Chirp; Chromatic dispersion; Fiber lasers; Laser tuning; Optical pulse generation; Optical pulses; Pulse generation; Signal generators; Tunable circuits and devices; Ultrafast optics; Fiber optics; microwave photonics; photomixing; submillimeter-wave generation;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2007.898872
