Deep-UV nitride-on-silicon microdisk lasers

Abstract

Deep ultra-violet semiconductor lasers have numerous applications for optical storage and biochemistry. Many strategies based on nitride heterostructures and adapted substrates have been investigated to develop efficient active layers in this spectral range, starting with AlGaN quantum wells on AlN substrates and more recently sapphire and SiC substrates. Here we report an efficient and simple solution relying on binary GaN/AlN quantum wells grown on a thin AlN buffer layer on a silicon substrate. This active region is embedded in microdisk photonic resonators of high quality factors and allows the demonstration of a deep ultra-violet microlaser operating at 275 nm at room temperature under optical pumping, with a spontaneous emission coupling factor β = (4 ± 2) 10−4. The ability of the active layer to be released from the silicon substrate and to be grown on silicon-on-insulator substrates opens the way to future developments of nitride nanophotonic platforms on silicon.

Ultrathin AlN‐Based HEMTs Grown on Silicon Substrate by NH3‐MBE

“…The AlN buffer layer grown on Si is very smooth (RMS roughness <2 Å), compact since the very first nanometers (no pits and no holes) and the dislocation density can reach the mid 10 10 cm −2 . Recently, by adding 20 pairs of AlN/GaN QWs directly on such a 100 nm‐thick AlN buffer layer grown on Si, lasing in the deep‐UV was observed at 300 K using a microdisk geometry . It demonstrates the potential of using ultrathin AlN‐based epistacks on Si.…”

Nanoscale Structural and Emission Properties within “Russian Doll”‐Type InGaN/AlGaN Quantum Wells

“…For extremely thin III-Nitrides quantum wells and quantum disks, the quantum confinement effect is strong when the thickness is 1-3 atomic monolayers. [30][31][32][33][34][35] In our system, the thickness of each InGaN or AlGaN layer is measured to be 9 atomic monolayers or above, thick enough to neglect the spatial quantum confinement. Since the contrast of the HAADF-STEM images is highly dependent on the effective atomic number (Z), and elements with a higher Z appear brighter in the resulting image, [36] InGaN layers are brighter than the neighboring AlGaN layers in the GaN NR.…”

Demonstration of critical coupling in an active III-nitride microdisk photonic circuit on silicon

“…For the m = 86 mode P th = 1.7 mJ/cm 2 per pulse. The other below-threshold modes are not visible due to the pulsed excitation with top-collection, a configuration that does not allow for easy detection of modes below threshold 15 . Similar lasing spectra for g = 30 nm and g = 55 nm are shown in Fig.…”

“…The main advantages of this material system are the possibility to have active monolithically integrated laser sources from the ultra-violet to visible (UV-VIS) spectral range and a large transparency window for energies smaller than 6 eV. There have been numerous demonstrations of microlasers [10][11][12][13][14][15] and high quality (Q) factor microresonators using III-nitrides [16][17][18] . Several reports have been made on passive microdisks evanescently coupled to bus waveguides in the UV-VIS spectral range [19][20][21] , but only very few demonstrations of active microlaser photonic circuits have been reported 22 , while critical coupling has been observed in passive photonic circuits in the IR [23][24][25][26] .…”