15-GHz modulation bandwidth, ultralow-chirp 1.55-μm directly modulated hybrid distributed Bragg reflector (HDBR) laser source

Direct modulation of multimode fiber Bragg grating external cavity lasers

“…It has been shown that the small-signal frequency response of the long cavity MMFBG-ECL is poor, which is unsuitable for light sources in wide-band optical communication systems [4].…”

“…As compared with traditional single mode fiber Bragg grating external cavity lasers (SMFBG-ECLs) [3,4], unique steady characteristics have been demonstrated experimentally and analyzed theoretically for MMFBG-ECLs. For example, MMFBG-ECLs have higher slope efficiency; it can select different lasing wavelengths by the MMFBG, which may facilitate wavelength-division multiplexing (WDM) channels in single mode fiber (SMF) wide area networks or multimode fiber (MMF) local-area networks (LAN); and by tuning the temperature of the MMFBG a large lasing wavelength range can be covered [2].…”

“…On the other hand, in SMF optical communication networks, WDM has already been realized with different fixed wavelength DFB lasers fitting each WDM channel. It has been demonstrated that SMFBG-ECL is also competent in this task with better performances than direct modulated DFB lasers [3,4]. However, a SMFBG-ECL can lock only one wavelength.…”

80 km transmission at 10 Gbps using a directly-modulated miniature planar-external-cavity (PLANEX) laser

“…Standard directly-modulated DFB lasers have large wavelength chirp that result in under 10km reach at 1550nm, with additional reach possible through the addition of an external filter [1]. External cavity lasers (ECL) using a fiber Bragg grating (FBG) have been shown to operate at 10Gbps with much lower chirp [2,3]; a 10Gbps FBG based ECL was shown to transmit over 40km of SMF with dispersion power penalty of 3.8dB [4]. In this presentation, we describe the record results of a directly modulated PLANEX ECL, which has achieved 80km transmission distances at 10Gbps with a power penalty of only 1.4dB, due to optimized chirp characteristics.…”

Wavelength-switchable fiber grating laser with wavelength stabilization

“…Data transmission with direct modulation of FGLs requires low front-end face reflectivity 6 and short resonator lengths. 3 One problem with FGLs is that the Bragg grating itself as a wavelength stabilization element does not prevent wavelength shifts inside the grating reflection range, nor intensity fluctuations or mode hops. 2 On the other side, the external cavity modes and the modes from the semiconductor amplifier section can be controlled actively to obtain a wavelength-switchable, mode-hop-free, and wavelengthstable fiber grating laser with linear power-versus-current characteristics.…”