1D photonic crystal direct bandgap GeSn-on-insulator laser

Abstract

GeSn alloys have been regarded as a potential lasing material for a complementary metal-oxide-semiconductor-compatible light source. Despite their remarkable progress, all GeSn lasers reported to date have large device footprints and active areas, which prevent the realization of densely integrated on-chip lasers operating at low power consumption. Here, we present a 1D photonic crystal nanobeam with a very small device footprint of 7 lm 2 and a compact active area of $1.2 lm 2 on a high-quality GeSn-on-insulator substrate. We also report that the improved directness in our strain-free nanobeam lasers leads to a lower threshold density and a higher operating temperature compared to the compressive strained counterparts. The threshold density of the strain-free nanobeam laser is $18.2 kW cm À2 at 4 K, which is significantly lower than that of the unreleased nanobeam laser ($38.4 kW cm À2 at 4 K). Lasing in the strain-free nanobeam device persists up to 90 K, whereas the unreleased nanobeam shows quenching of lasing at a temperature of 70 K. Our demonstration offers an avenue toward developing practical group-IV light sources with high-density integration and low power consumption.

Chiral germanium micro-gears for tuning orbital angular momentum

“…Emission of the cavity provide the privilege of inspecting the spectral response from an internal source, overcoming the issues of coupling to an external waveguide and the resulting irrelevant resonant modes. Ge 9 , 10 and 22 – 24 alloys are being investigated as candidate materials for CMOS-compatible light sources. Thus, in our study we have integrated our design on a Ge micro-gear cavity (Fig.…”

“…Namely, on-chip optical communications with two-dimensions of multiplexing—wave and space division multiplexing—for extremely high data-rates 31 . Consequently, Ge was chosen being a promising CMOS-compatible gain medium 9 , 10 , 25 – 29 , especially with the recent lasing reports of Ge and 22 – 24 , although the cavity concept applies to any waveguiding material. This is evident in the sharp-peak resonances observed in Fig.…”

Impact of strain engineering and Sn content on GeSn heterostructured nanomaterials for nanoelectronics and photonic devices

“…36 Hyo-Jun Joo et al prepared 550 nm thick, 10.6% Sn content GeSn layer deposited on Al 2 O 3 and SiO 2 insulating layers on Si, then the Al 2 O 3 layer was selectively etched so that GeSn is on SiO 2 , which serves in optical confinement and enhances the GeSn emission threshold. They obtained 2204 nm lasing line with a pumping threshold density of 18.2 kW cm −2 at 4 K. 138 Youngmin Kim et al prepared a p–i–n heterostructure of 3 GeSn layers with 5–7–5% Sn content deposited on 130 and 200 nm buffer GeSn layers on Ge above the Si substrate, then the Ge buffer was selectively etched so that 11 μm diameter microdisk was directly stacked on Si. A 2215 nm lasing line was detected at 4 K with a pumping threshold power equal to 60 kW cm −2 .…”

Growth and Strain Modulation of GeSn Alloys for Photonic and Electronic Applications

“…Inspired by this research, the first optically pumped FP cavity GeSn laser was demonstrated at low temperature [ 32 ]. From then on, other lasers were successfully demonstrated: GeSn micro-disk lasers [ 33 ], 2D hexagonal photonic crystal (PC) cavity GeSn lasers [ 34 , 35 ], micro-bridge cavity GeSn lasers [ 36 ], 1D PC cavity GeSnOI lasers [ 37 ], GeSn/SiGeSn quantum wells lasers [ 38 ], GeSn micro-disk continuous wave (CW) lasers [ 39 , 40 ] and electrically pumped GeSn/SiGeSn lasers [ 41 , 42 ]. However, their thresholds were still very high, necessitating strategies to achieve both room temperature lasing and low thresholds.…”