Lasing Characteristics and Reliability of 1550 nm Laser Diodes Monolithically Grown on Silicon

Abstract

Room‐temperature continuous wave (RT‐CW) electrically pumped 1550 nm indium phosphide (InP)‐based laser diodes are realized on complementary metal‐oxide‐semiconductor (CMOS) compatible silicon (Si) substrates by direct heteroepitaxy. Dynamic properties are investigated by gain switching and small signal modulation measurements. A maximum 3 dB bandwidth of 5.3 GHz is demonstrated, along with a narrow optical pulse with a width of 1.5 ns. The dark current density of 490 mA cm−2 at −1 V bias is an order of magnitude higher than identical devices grown and fabricated on native InP substrates. Also, reliability measurements and failure analysis are carried out for the lasers on Si. The lasers operate stably over 200 hours (h) at 10 °C under CW operation without apparent change in threshold or output power. In sharp contrast, a rapid failure occurs at 60 °C under pulsed operation following 5.6 h of aging. To further improve device characteristics for lasers on Si, the dislocation density of the InP template is reduced by introducing a 2 μm‐thick compositionally graded In0.4Ga0.6 As buffer. The resulting surface defect density is as low as 4.5 × 107 cm−2, which is expected to improve the performance and reliability of long wavelength lasers grown directly on Si.

High-power, electrically-driven continuous-wave 1.55-μm Si-based multi-quantum well lasers with a wide operating temperature range grown on wafer-scale InP-on-Si (100) heterogeneous substrate

“…It is important to note that the uneven increased J th for the 1750 µm long laser may be due to the improperly split facet. The minimum J th of 0.65 kA/cm −2 was achieved with a cavity length of 1.5 mm at RT under CW mode, which is the lowest J th ever recorded for a Si-based FP laser emitting at 1.55 μm 20 .

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“…The FP lasers have a threshold current density of 2.05 kA/cm 2 at RT, and can be operated at up to 65 °C under CW mode with a relatively thin III-V buffer layer (5.9 μm). In contrast, a rapid device failure occurred at 60 °C after just 5.6 hours of aging under pulsed operation due to the high TDD of 1.15 ×10 8 cm −3 20 . Besides InGaAs/InGaAsP MQW lasers, InAs/InAlGaAs quantum dashes (QDashs) and QDs have also been used as the active gain medium emitting at the 1.55 μm telecommunication wavelength.…”

Recent Progress of Quantum Dot Lasers Monolithically Integrated on Si Platform

“…The operating wavelength range is focused on O-band due to the utilisation of InAs/GaAs QDs. Although C-band operation based on the InP platform is also crucial for mid/long-haul communication, the progress of 1.55 µm QD lasers on Si has been hindered by far more significant lattice mismatch between InP and Si than that between GaAs and Si [86,87]. Indeed, unlike QD lasers grown on InP native substrate, C-band QD lasers on on-axis (001) Si can operate only under pulsed injection with a high threshold current density of 1.6 kA/ cm 2 due to high TDD and rough epilayer surface [88].…”

Quantum Dot Lasers Directly Grown on 300 mm Si Wafers: Planar and In-Pocket

“…The monolithic integration of III-V light sources on Si through heteroepitaxial growth with molecular-beam epitaxy (MBE) and metalorganic chemical vapor deposition (MOCVD) has gained major attention in recent years [18][19][20][21][22][23][24], highlighting the merits of using quantum dots (QDs) as the gain material [25][26][27][28], especially with their improved tolerance to crystalline defects [29][30][31]. Through extensive defect mitigation efforts, e.g., by growing asymmetric step-graded filters to reduce threading dislocation densities (TDDs) and introducing trapping layers to block misfit dislocations (MDs), QD lasers grown by MBE on Si have been demonstrated with excellent performance and good reliability [32][33][34][35].…”