Improved quantum efficiency of GaInAsP/InP top air-clad lateral current injection lasers

Room-temperature continuous-wave operation of GaInAsP/InP lateral-current-injection membrane laser bonded on Si substrate

“…The internal quantum efficiency, © i , of 75% is close to that of our one-step grown vertical injection lasers, as well as to the results for our LCI lasers prepared on a semi-insulating InP substrate. 19) This indicates that nonradiative carrier recombinations at both the top and bottom surfaces of the membrane structure are almost negligible, which is attributed to 50-nm-thick InP cap layers as well as high-quality buried heterostructure interfaces prepared by two-step OMVPE regrowth. In addition, this high internal quantum efficiency indicates that there is minimal leakage current through the p-InP cap layer to the n-InP layer.…”

“…For the current-injection operation, we adopted a lateralcurrent-injection (LCI) structure 18) and obtained RT-CW operation of LCI lasers prepared on a semi-insulating InP substrate. 19) To prepare the membrane structure, we utilized the wafer bonding technique 15,20) using benzocyclobutene (BCB) as an intermediate layer. RT-CW operation of LCI-membrane (core thickness 220 nm) lasers prepared on an InP substrate was realized.…”

“…However, the waveguide loss, ¡ WG , of 42 cm ¹1 is very large compared with our previously reported value (5.1 cm ¹1 ) for LCI lasers on a semi-insulating InP substrate. 19) This may be attributed to scattering loss arising from the steps at the regrown interface between the mesa stripe and the InP cladding layers. Because the electric field is strongly confined in the thin semiconductor core, these steps induce a large scattering loss.…”

10 Gbps Operation of Top Air-Clad Lateral Junction Waveguide-Type Photodiodes

“…3) In order to realize electrically pumped membrane lasers, a lateralcurrent-injection (LCI) structure 4) was adopted, and moderate performance was confirmed for LCI-type lasers prepared on a semi-insulating (SI)-InP substrate. [5][6][7][8] Recently, an LCI membrane DFB laser prepared with a BCB bonding process was demonstrated with a relatively low threshold current of 11 mA. 9) Furthermore, we proposed membrane photonic integrated circuits (PICs) consisting of an LCI-membrane-DFB, an InP-based wire waveguide, and other semiconductor components as a candidate for an in-plane photonic platform with extremely low-power consumption.…”

“…In the lateral junction type photodiode, the surface recombination on the interface between semiconductor and air on the top of the stripe thought to be cause of the low internal quantum efficiency i . In case of the lateral current injection laser, the thicker InP cap layer 7) or the uniformly distributed quantum well structure 8) were proposed in order to suppress the surface recombination on the top of the stripe. These structures can be also applied for the lateral junction type photodiode toward enhancement of the responsivity more than 70%.…”