Isolator-free > 67-GHz bandwidth DFB+R laser with suppressed chirp

Abstract

We report on simultaneous realization of > 67 GHz bandwidth, a reflection tolerance up to 12.5 %, and a record-low chirp parameter of 0.6 for a DFB laser integrated with a passive waveguide with 3% reflection coating, called DFB+R laser.

>100-GHz Bandwidth Directly-Modulated Lasers and Adaptive Entropy Loading for Energy-Efficient >300-Gbps/λ IM/DD Systems

“…In order to achieve single-channel IM/DD operations with >300 Gbps in an effective and power-efficient manner, optical transceivers with large analog bandwidths of >65 GHz are required [3,10,16]. When it comes to such wide-bandwidth optical transceivers, a flat end-to-end system frequency response is rarely achieved without the support of some advanced digital signal processing (DSP) technique.…”

“…cost-per-bit, power consumption, and device footprints. In particular, IM/DD systems that utilize wide-bandwidth directly-modulated lasers (DMLs) [2][3][4][5] are arguably the most energy-efficient approach, which could pose such lasers among the leading technologies to support ICT growth in the future.…”

Beyond the 100 Gbaud directly modulated laser for short reach applications

“…To overcome the K-limited bandwidth ( ), a variety of coupled-cavity laser structures composed of active sections and passive feedback cavities have been proposed (No. 12-22 of Table 4) [16,17,[32][33][34][35][36][37][38][39][40] . These advanced structures can be classified into four types: (1) a multiple-section distributed Bragg reflector (DBR) lasers [32,33] ; (2) passive feedback lasers [34][35][36][37] ; (3) a distributed reflector (DR) Lasers [16,38,39] ; and (4) DFB+R lasers [17,40] , as shown in Fig.…”

Harnessing Advanced Dynamic Effects for High Performance Directly Modulated Lasers

“…Due to the need for an external cavity, the detuned loading effect is always accompanied with PPR effects. The combined effect of detuned loading and PPR has led to a recent demonstration of 65 GHz BW DML with a significantly reduced linewidth enhancement factor of about 0.6 [10]. In addition to the DBR design, the detunedloading effect can also be generated in a "DFB+R" structure [11], where a passive waveguide section with a low reflectivity of ~3% at the front facet is integrated with the DFB section.…”