Quantum dot selective area intermixing for broadband light sources

Abstract

We report a comparison of different capping materials on the intermixing of modulation p-doped InAs/In(Ga)As quantum dots (QD). QD materials with different caps are shown to exhibit significant difference in their optical properties during the annealing process. The selective area intermixing technique is demonstrated to laterally integrate two and three different QD light emitting devices with a single electrical contact. A spectral bandwidth of 240nm centered at 1188nm is achieved in a device with two sections. By calculating the point spread function for the obtained emission spectra, and applying the Rayleigh criteria for resolution, an axial resolution of 3.5μm is deduced. A three section device realizes a spectral bandwidth of 310nm centered at 1145nm. This corresponds to an axial resolution of 2.4μm. Such a small predicted axial resolution is highly desirable in optical coherence tomography system and other coherence-based systems applications.

Investigation of Chirped InAs/InGaAlAs/InP Quantum Dash Lasers as Broadband Emitters

“…This is achieved either by deliberate increase of the dot/dash size distribution during growth (pre-growth bandgap engineering), normally termed as chirped active region, or by post growth bandgap engineering such as intermixing. In general, a substantially broadened SLD emission is reported spanning > 300 nm in the O-band by monolithic integration of multiple selectively intermixed active region [10]. We successfully established the capability of this technique under the stimulated emission regime by demonstrating enhanced lasing bandwidth of ∼ 41 nm from InAs/InP Qdash with improved device characteristics and emission in the C-band [11].…”

Long-Wavelength InAs/GaAs Quantum-Dot Light Emitting Sources Monolithically Grown on Si Substrate

“…To the best of our knowledge, this is the first demonstration of III-V InAs QD SLD on Si substrates and is a result of optimizing DFLs and careful control of dots size inhomogeneity. Further improvements in linewidth can be expected through using chirped QDs [31], QDs intermixing [32], and hybrid QW/QD structure [33,34].…”

Unlocking Spectral Versatility from Broadly−Tunable Quantum−Dot Lasers

“…While these results were achieved with identical QD layers, a recent new formulation of the structure including non−identical QD layers has led to the demonstration of a 350 nm wide spontaneous emission spectra [92]. The advance of techniques based on selective area intermixing of QD structures has also resulted in 310 nm bandwidth centered at 1145 nm for a device with three sections with different intermixing properties [93], offering more degrees of freedom on QD structure engineering.…”