Distorsion i halvledarlasrar avsedda för kommunikation över korta avstånd
Typ
Examensarbete för kandidatexamen
Bachelor Thesis
Bachelor Thesis
Program
Engineering Physics (300 hp)
Publicerad
2011
Författare
Haglund, Emanuel P.
Eliasson, Henrik
Fülöp, Attila
Wohlén, Andreas
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Nonlinearities for four different laser configurations have been measured and compared, one DFB laser, one laser modulated externally with a Mach-Zehnder modulator, one VCSEL made at Chalmers and one commercially produced VCSEL. Measurements and analysis of second order harmonic distortion (HD2) and third order intermodulation distortion (IMD3) has been performed. From the results of the measurement, spurious free dynamic range (SFDR) has been calculated and compared. In particular: the VCSEL built at Chalmers has been compared to the commercially produced one. Out of these two, the one made at Chalmers showed better values for SFDR. The behavior of lasers has been analyzed from a theoretical model with third order Taylor series and rate equations. The laser built at Chalmers has been computer simulated from its DC-characteristics and the results from the computer simulation have been compared to the experimental values. It turned out that the laser had a more linear behavior when modulated with high frequency signals than DC-supply.
Beskrivning
Ämne/nyckelord
Fotonik , Informations- och kommunikationsteknik , Nanovetenskap och nanoteknik , Photonics , Information & Communication Technology , Nanoscience & Nanotechnology