Laterally coupled distributed feedback lasers emitting at 2 μm with quantum dash active region and high-duty-cycle etched semiconductor gratings

Abstract

Single-mode diode lasers on an InP(001) substrate have been developed using InAs/In0.53Ga0.47As quantum dash (Qdash) active regions and etched lateral Bragg gratings. The lasers have been designed to operate at wavelengths near 2 μm and exhibit a threshold current of 65 mA for a 600 μm long cavity, and a room temperature continuous wave output power per facet >5 mW. Using our novel growth approach based on the low ternary In0.53Ga0.47As barriers, we also demonstrate ridge-waveguide lasers emitting up to 2.1 μm and underline the possibilities for further pushing the emission wavelength out towards longer wavelengths with this material system. By introducing experimentally the concept of high-duty-cycle lateral Bragg gratings, a side mode suppression ratio of >37 dB has been achieved, owing to an appreciably increased grating coupling coefficient of κ ∼ 40 cm−1. These laterally coupled distributed feedback (LC-DFB) lasers combine the advantage of high and well-controlled coupling coefficients achieved in conventional DFB lasers, with the regrowth-free fabrication process of lateral gratings, and exhibit substantially lower optical losses compared to the conventional metal-based LC-DFB lasers

Co-Package Technology Platform for Low-Power and Low-Cost Data Centers

“…In fact, SiP would highly benefit from integrated laser sources exhibiting a higher temperature insensitivity combined with a low threshold current. As previously shown, low-dimensional nanostructures may exhibit these properties well owing to their lower density of states and smaller active volumes [29][30][31].…”

“…This made the coupling between the III-V and Si waveguides inefficient for many of the QD III-V structures, so special designs were required. The second major challenge concerned the fact that previous QD demonstrations [29][30][31][32][33] always utilized thick gain stacks (epitaxial III-V thickness > 2 µm) in order to provide sufficient material gain and low losses [37]. From the L3MATRIX perspective, considering thin gain stacks that would be compatible with industrial production lines is highly desirable.…”

InAs/GaAs quantum dot laterally coupled distributed feedback lasers at 1.3 μm

“…Uniform Cr gratings with periods of 196.5 nm are clearly shown, which are covered by a silicon nitride isolation layer and the top electrode metal films. According to the coupled-wave theory, the coupling coefficient is given by [16,17]…”

High-order topological states using alignment of different bandgaps in 1D superlattices

“…8,[12][13][14] This presents intriguing possibilities, as DBR or distributed feedback (DFB) mirror-based cavities are widely used in photonics applications, enabling high-quality and reliable cavities in various configurations . [15][16][17][18][19][20][21][22][23][24] Consequently, this may offer a promising avenue to seamlessly integrate topological structures with these established photonic technologies.…”