Chirp Control of Semiconductor Laser by Using Hybrid Modulation

Mitsunari KANNO  Shigeru MIEDA  Nobuhide YOKOTA  Wataru KOBAYASHI  Hiroshi YASAKA  

IEICE TRANSACTIONS on Electronics   Vol.E101-C   No.7   pp.561-565
Publication Date: 2018/07/01
Online ISSN: 1745-1353
DOI: 10.1587/transele.E101.C.561
Type of Manuscript: INVITED PAPER (Special Section on Distinguished Papers in Photonics)
dispersion tolerance,  frequency chirp,  frequency response,  semiconductor lasers,  

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Frequency chirp of a semiconductor laser is controlled by using hybrid modulation, which simultaneously modulates intra-cavity loss and injection current to the laser. The positive adiabatic chirp of injection-current modulation is compensated with the negative adiabatic chirp created by intra-cavity-loss modulation, which enhances the chromatic-dispersion tolerance of the laser. A proof-of-concept transmission experiment confirmed that the hybrid modulation laser has a larger dispersion tolerance than conventional directly modulated lasers due to the negative frequency chirp originating from intra-cavity-loss modulation.