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

Ogusu

et al. 2019

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We measured the two-color laser oscillation from a GaAs/AlGaAs-coupled multilayer cavity at 18 °C-42 °C using current injection. We confirmed simultaneous lasing by detecting the sum frequency generation signal generated by the two-color laser light, and performed time-resolved measurement using a streak camera with a spectrometer. From the observed time transient of the spectra at various temperatures, it is clarified that the temperature change of the device, induced by current injection, modulates the effective cavity length. Therefore, the temperature control of the device is a key factor in stable two-color lasing and THz wave generation.

Section: Introductionmentioning

confidence: 99%

Time-resolved measurements of two-color laser light emitted from GaAs/AlGaAs-coupled multilayer cavity

Ogusu

et al. 2019

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“…To obtain terahertz emission through DFG without external light sources, we have fabricated the structure by current injection from the viewpoint of practical device application. [20][21][22][23] The opposite signs of χ (2) (second-order nonlinear susceptibility) in the two cavity regions are necessary to realize a stronger THz-DFG of two modes. The sign of χ (2) can be inverted by the 180°rotation of the crystal around the appropriate axis.…”

Section: Introductionmentioning

confidence: 99%

Sublattice reversal in GaAs/Ge/GaAs (113)B heterostructures and its application to THz emitting devices based on a coupled multilayer cavity

Kumagai

et al. 2018

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We fabricated a coupled multilayer cavity with a GaAs/Ge/GaAs sublattice reversal structure for terahertz emission application. Sublattice reversal in GaAs/Ge/GaAs was confirmed by comparing the anisotropic etching profile of an epitaxial sample with those of reference (113)A and (113)B GaAs substrates. The interfaces of GaAs/Ge/GaAs were evaluated at the atomic level by scanning transmission electron microscopy (STEM) and energy-dispersive X-ray spectroscopy (EDX) mapping. Defect-free GaAs/Ge/GaAs heterostructures were observed in STEM images and the sublattice lattice was directly seen through atomic arrangements in EDX mapping. A GaAs/AlAs coupled multilayer cavity with a sublattice reversal structure was grown on the (113)B GaAs substrate after the confirmation of sublattice reversal. Smooth GaAs/AlAs interfaces were formed over the entire region of the coupled multilayer cavity structure both below and above the Ge layer. Two cavity modes with a frequency difference of 2.9 THz were clearly observed.

“…In our most recent study, we demonstrated two-color lasing from a strongly coupled two-cavity system that contains InGaAs MQWs with two different well widths solely in the upper cavity layer. 32) The coupled cavity structure of that study was formed without using the wafer bonding method and the two-color lasing of the currentinjection device was observed under pulsed conditions at room temperature. In this study, we fablicated currentinjection surface-emitting devices using a wafer-bonded coupled cavity containing InGaAs MQWs and investigated their emission properties.…”

Section: Introductionmentioning

confidence: 99%

Current-injection two-color lasing in a wafer-bonded coupled multilayer cavity with InGaAs multiple quantum wells

Ota

et al. 2017

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Current-injection two-color lasing has been demonstrated using a GaAs/AlGaAs coupled multilayer cavity that is a good candidate for novel terahertz-emitting devices based on difference-frequency generation (DFG) inside the structure. The coupled cavity structure was fabricated by the direct wafer bonding of (001)- and (113)B-oriented epitaxial wafers for the efficient DFG of two modes in the (113)B side cavity, and two types of InGaAs multiple quantum wells (MQWs) were introduced only in the (001) side cavity as optical gain materials. The threshold behavior was clearly observed in the current–light output curve even at room temperature. Two-color lasing was successfully observed when the gain peaks of MQWs were considerably tuned to the cavity modes by the operating temperature.