Bandwidth enhancement of single-mode VCSEL with lateral optical feedback of slow light

Abstract

Abstract:In this paper a novel method to increase the modulation bandwidth of vertical-cavity surface-emitting lasers (VCSEL) is proposed. The modeling predicts that the modulation bandwidth can be enhanced by 60% with lateral optical feedback. Even if the relaxation oscillation frequency is below 15 GHz without optical feedback, the modulation bandwidth can reach at 40 GHz beyond the limit of a relaxation oscillation frequency. Small and large-signal-modulation analysis is carried out. The result shows a potential of high-speed modulation beyond 40 Gbps for use in low-power consumption optical interconnects.

Intensity noise in ultra-high frequency modulated semiconductor laser with strong feedback and its influence on noise figure of RoF links

“…The figure indicates also that the maximum response enhancement is obtained when ∆θ = 1.3π, and the peaked modulation frequency of the response enhancement increases with the increase in the OFB coupling phase ∆θ. Enhancement of the modulation bandwidth under out-ofphase coupling feedback was reported by Koyama and Dalir [29] in VCSELs using a small-signal modulation analysis in a weak-coupling regime. Thus it is noted that the phase of optical feedback should be controlled for getting the modulation response enhancement over the mm wave band.…”

Advances and new functions of VCSEL photonics

“…39) We proposed the optical feedback scheme for enhancing the modulation bandwidth of VCSELs. 40) The optical feedback has been successfully employed for increasing the speed of distributed-feedback/distributed Bragg-reflector (DFB/ DBR) lasers. [51][52][53] We demonstrated the bandwidth extension by exploiting a transverse coupled cavity, which reached the record 3-dB bandwidth of over 29 GHz and large signal modulation up to 36 Gbps for 980 nm VCSELs.…”

“…We proposed and demonstrated the lateral integration scheme. [40][41][42] A VCSEL structure can be used as an optical waveguide in the lateral direction, which is called as a Bragg reflector waveguide. 43) Slow light can be seen in Bragg reflector waveguides with their large waveguide dispersion.…”

Modulation bandwidth enhancement of quasi-single-mode transverse coupled cavity VCSEL

“…To increase the speed of VCSELs, various approaches have been studied [2][3][4][5]. We proposed and demonstrated the bandwidth enhancement using a transverse coupled cavity, which offered the record 3dB bandwidth of over 29GHz [6,7]. The drawback is to need a precise phase tuning current in a multi-mode coupled cavity.…”