摘要： Mid-infrared semiconductor light sources emitting around 2–3 μm wavelength are instrumental for an increasing number of applications, such as molecular spectroscopy, trace-gas sensing, medical diagnostics and eye-safe LIDAR. For example, the monitoring of greenhouse gases (C2H2, CO2, CO and N2O) can be done with higher sensitivity using their molecular fingerprints in this wavelength range [1]. On the other hand, for a wider penetration to applications other important aspects, such as cost, power efficiency, portability and reproducibility are the key enablers. To this end, mid-IR silicon-photonics technology has emerged as a developed platform, yet so far relaying on the use of extended-cavity tunable laser concepts [2]. Alternatively, we have proposed the use of high power, spectrally broadband ridge waveguide (RWG) GaSb-based superluminescent diodes (SLDs) exhibiting single-transverse mode for efficient coupling to silicon photonics waveguide and enabling the development of spectral-programmable broadband light sources [3]. While 2–3 μm GaSb-based laser diodes have shown a good level of performance, yet the development of SLDs devices has seen little progress, owing to the peculiarity of GaSb material system, which is less spread as optoelectronics platform, and physics consideration, for example linked to increased Auger recombination. Most recent developments in the performance of GaSb gain-chips at room temperature (RT) include the demonstration of output powers of up to 60 mW at 1.9 μm [4], 10 mW at 2.25 μm, and 5 mW at 2.38 μm [5] for continuous-wave (CW) operation, and 3.2 mW average power at 2.55 μm [6] for pulse operation. Here we report a comparative study of using novel single- and double-pass SLED designs employing a cavity suppression (CS) element, shown in Fig.1. The active region consists of compressively strained GaInSb/AlGaAsSb double QWs [4]. We operated the devices under CW at RT. The double-pass approach has produced an output power up to 120 mW, which is 100% more than our previous single-pass demonstration. The high power is achieved due to the double-pass light amplification and better material quality. The cavity suppression element enabled high current injection with a broad spectrum having a spectral full width at half maximum (FWHM) of 70 nm and 40 nm for single- and double-pass SLDs, respectively. In conclusion, we reported the highest power GaSb-based SLD demonstrated so far, reaching a power level as high as 120 mW and a spectral bandwidth of 40 nm in a single-transvers mode-operation.