Effect of cavity-layer thicknesses on two-color emission in coupled multilayer cavities with InAs quantum dots

Abstract

A GaAs/AlAs coupled multilayer cavity structure was grown on a (001) GaAs substrate. The top cavity contains self-assembled InAs quantum dots (QDs) as optical gain materials for two-color emission of cavity-mode light. The bottom cavity layer was grown with lateral thickness variation in the wafer to investigate the effects of the thickness difference between the two cavity layers quantitatively. The frequency difference was minimum, and the intensity ratio of the two-color emission was unity when the optical thicknesses of the two cavity layers were the same. The emission intensity ratio was explained in terms of the electric fields at the top cavity region containing the QDs.

Surface Emitting Devices Based on a Semiconductor Coupled Multilayer Cavity for Novel Terahertz Light Sources

“…6 (c). This result was quite different from that previously observed when the entire structure was fabricated by MBE on the (001) substrate without using the wafer bonding [28]. In the case, emission intensity of each mode was almost identical as expected.…”

“…We have already demonstrated the two mode emission by optical excitation using self-assembled InAs quantum dots (QDs) that were inserted only in the one cavity layer to realize optical gain in the near-infrared region [26]- [28]. In this paper, we report recent progress on design and fabrication technologies of the GaAs-based coupled multilayer cavity toward compact and room-temperature operable terahertz light emitting devices.…”

Two-color surface-emitting lasers using a semiconductor coupled multilayer cavity

“…If the optical thickness of the lower cavity is less than that of the upper cavity, the electric fields of the shortand long-wavelength modes tend to localize in the lower and upper cavities, respectively. 30) In this case, the long-wavelength mode has a far stronger electric field in the MQW region compared with the short-wavelength mode, so that the stimulated emission is more likely to occur in the long-wavelength mode, as observed in Fig. 3(a).…”

“…Our group previously studied two-mode emission resulting from the optical excitation of a coupled multilayer cavity with self-assembled InAs quantum dots (QDs), [28][29][30][31] and we recently found that significant optical loss results from the bonding interface when this interface is located at an antinode in the electric-field distribution of the mode. 31) To understand the intrinsic characteristics of two-color lasing in the coupled multilayer cavity, the entire structure employed in this study was prepared by solid-source molecular beam epitaxy on a single (001) GaAs wafer.…”

Room-temperature two-color lasing by current injection into a GaAs/AlGaAs coupled multilayer cavity fabricated by wafer bonding

“…Two mode emission characteristics in the nearinfrared region have been studied by the optical pumping of self-assembled InAs quantum dots (QDs) that were introduced only in the upper cavity. [25][26][27] We have also fabricated current-injection surface-emitting devices based on a waferbonded coupled cavity with QDs. Although we introduced nine layers of InAs QD in the active region, the lasing action has not been realized yet owing to insufficient optical gain.…”